How to fertilize Serissa japonica? Dilute rice water once a week

Growing Techniques Jan 1, 1970 0 views

Serissa japonica, a highly ornamental plant, has dense branches and leaves, and when its white flowers bloom, it looks just like snowflakes covering the tree, extremely beautiful. However, if you want to grow Serissa japonica beautifully, there are many things to pay attention to. Pruning is one, and fertilizing is also essential. So how do you fertilize Serissa japonica?

I. How to fertilize Serissa japonica, fertilizer selection

If you want Serissa japonica to grow beautifully, on the outside we can prune it, and on the inside we need to fertilize it reasonably. How to prune Serissa japonica has been introduced earlier, so how do you fertilize Serissa japonica? As far as the editor is concerned, knowing two points is enough: one is what fertilizer to choose; the other is when to fertilize. The details are as follows:

(1) What fertilizer to use for Serissa japonica, rice water

How to fertilize Serissa japonica, first of all naturally means choosing fertilizer. For this, the editor recommends a simple method: find a Jianlibao (JDB) bottle (Jiaduobao works too), fill it with rice water, then seal and ferment for two weeks. After that, dilute the fermented rice water 30-50 times, then use it as fertilizer for Serissa japonica, applying it once a week. Apply thin fertilizer frequently!

(2) Serissa japonica fertilization time, April-May

Serissa japonica likes fertilizer, but this does not mean you can fertilize it at any time. Only by choosing the right time is fertilization useful. As for the fertilization time for Serissa japonica, generally choose April-May. At this time we can use 0.5% phosphorus-potassium fertilizer to water it appropriately, so that Serissa japonica can grow better.

II. Fertilization methods for Serissa japonica

Now that you know the fertilization time for Serissa japonica and what fertilizer to use, next it is time to officially start fertilizing. For this, there are also techniques to speak of. The fertilization methods for Serissa japonica are as follows:

1. Fertilizing Serissa japonica in winter

Besides fertilizing in April-May, the only other time is winter fertilization. Many flower lovers may say that winter is so cold that Serissa japonica should be dormant and should not need fertilizer. Actually, thinking this way is wrong. In winter, we can give it one additional fertilization!

At this time flower lovers can irrigate Serissa japonica with a little thinner and lighter organic fertilizer, but only add this one time. After applying it, do not apply again. Too much is also bad and will affect its growth and have the opposite effect.

2. Do not fertilize too much

For beginners, the more fertilizer, the better Serissa japonica grows, but this idea is wrong! Because if we fertilize Serissa japonica too much, it will only keep growing taller, making the overall plant shape extremely ugly. So be sure not to fertilize too much. Controlling the amount of fertilizer is very important.

3. Do not use concentrated fertilizer

In the fertilization methods for Serissa japonica, besides not fertilizing too much, you also cannot use concentrated fertilizer! Serissa japonica itself likes thinner fertilizer. If the fertilizer we use is too concentrated, it will have the opposite effect. In severe cases, it can cause root rot, leading to yellowing and falling leaves, and even death.

Bonsai management in spring, summer, and autumn and small bonsai making

According to natural laws, potted flowers should have withered leaves and fallen flowers in the severe cold of winter, and be full of blooming flowers and spring vitality in spring. But things are often completely the opposite. In many households, potted flowers have green leaves and red flowers in winter, yet in spring their leaves turn yellow and flowers fall. This is especially true for famous flowers such as Milan, Michelia figo, camellia, and rhododendron, which not only show flower drop and leaf drop, but some even die entirely. What is the reason? The factors are many, but the main ones are as follows.

Moving potted flowers outdoors to bask in the sun too early. Because the indoor temperature at night is relatively low, the sudden temperature change shocks the root system.
Watering too much in early spring. Especially in northern regions, after heating is stopped, the indoor temperature is relatively low, the plant's water absorption capacity is poor, and too much water easily causes root rot. Applying concentrated fertilizer in early spring, especially watering flowers with unfermented fresh milk, sesame paste, or liquid fertilizer containing too much oil, causing the potted flowers to be "burned to death," is the third reason. In addition, in winter potted flowers receive less sunlight indoors, and the branches are tender and weak. If they are moved out too early in early spring and hit by cold wind, they will also be damaged.
Spring is the golden season for repotting. At this time, flowers are in a dormant stage, wounds heal easily after repotting, and the flowers can obtain abundant nutrients, laying a good foundation for the whole year's growth. Herbaceous flowers, because they grow quickly and have a short growth cycle, should be repotted once a year; woody flowers, such as plum, wintersweet, pomegranate, and Chinese rose, can be repotted once every other year; evergreen flowers such as pines, cypresses, and bamboos, because they grow slowly, can be repotted once every 2-3 years or 4 years. Large bonsai or tree-stump bonsai do not need their pot size increased year by year; you can perform ring-shaped soil replacement or root pruning in the original pot, and repot once after several years. Generally, new pots should first be soaked and thoroughly soaked in water before use. It is even better if the pot is first soaked thoroughly in fertilizer water. If you continue using an old pot, it should be cleaned to prevent the original pathogens in the pot from infecting the newly replaced soil.
When repotting, first use a piece of tile to cover the drainage hole at the bottom of the pot, then spread a layer of cultivation soil at the bottom of the pot. When repotting, remove 1/4-1/3 of the old soil, remove old and decayed roots, then plant it into the pot.
Watering: The potting soil should be pressed firm, and new soil added to 2-3 cm from the pot rim. The first watering should be thorough, then place it in a cool place. After about a week, place it in the sun.

1. Avoid fertilizing. In the high heat of midsummer, leaves lose water relatively quickly. Fertilizing at this time will make the concentration of the cell sap in the stump lower than the concentration of the external environment, causing plant cell water to flow back into the soil, and the stump dies from water loss due to fertilizer damage.
2. Avoid drought. Watering when you remember and not watering when you do not, sometimes ignoring it for several days in a row, and only quickly replenishing water once the leaves are found wilted, after which the leaves recover, is a reaction of the stump adapting to the environment. But if this continues long term, the overly strong transpiration will eventually make the stump difficult to recover from serious illness and die of dehydration.
3. Avoid waterlogging. Some people think that frequent watering during high temperatures is beneficial to stump growth. In fact, if the potting soil is too wet, the root system is in an anaerobic respiration state for a long time, and the stump's root function of absorbing water, inorganic salts, and minerals fails, eventually drowning to death.
4. Avoid sunscald. When the environmental temperature exceeds 28°C, the bonsai should be shaded. Otherwise, the amount of water the stump obtains from the soil is far lower than the water lost through transpiration. In mild cases, leaf edges are scorched and withered; in severe cases, the stump is scorched and dies from severe damage.
5. Avoid sudden shading. Usually, to avoid high-temperature damage, when the environmental temperature exceeds the maximum temperature the stump can tolerate, the bonsai should be moved to a lower-temperature area with weaker light, about 2°C lower, to benefit stump growth. But if it is suddenly moved indoors or to a lower-temperature area, within a few days the leaves will naturally fall off, and the tree stump will shrink and die.

Bonsai tree stumps are planted in pots. Generally the pot is shallow and the soil is thin, so moisture in the potting soil is not easy to retain. In addition, summer temperatures are high, water evaporates easily, and tree stumps have a large water requirement. If the tree stump cannot be watered in time at this time, it will lead to water deficiency, a dry stump, and death when the potting soil dries up. How to correctly meet the watering requirements of tree stumps in summer, you must grasp the following points:
1. Grasp the relationship between potting soil and water temperature well: for general watering, the potting soil temperature and water temperature should remain the same or similar. If the difference between potting soil temperature and water temperature is too large, do not water. Especially in summer, when the temperature is relatively high, if you water the tree stump with water at a relatively low temperature, the root system is stimulated by cold water and its absorption performance will weaken. In particular, the leaves of the tree stump, when doused with cold water, the stomata that were originally open on the leaves immediately contract and close upon cold-water stimulation, producing a "physiological drought" phenomenon, causing leaf shrinkage and making the potted stump grow poorly for a long time. When watering in summer, you should also water only when the water temperature is the same or similar to the soil temperature and air temperature.
2. Pay attention to the water quality for watering: for watering potted stumps, rainwater, river water, and pond water are best. Especially for acid-loving tree stumps in the south, rainwater is best for watering, and river water and pond water are also acceptable. But in the north, because the soil tends to be alkaline, river water and pond water also often contain saline-alkaline components. Using this kind of water to water flowers is unfavorable to the growth of acid-loving flowers and trees. At this time, if there is no rainwater to water the stumps, you can use well-rotted rice water diluted and then water the stumps. In addition, tap water and wastewater changed from a goldfish tank can also be used to water neutral and slightly alkaline tree stumps. If using tap water, it must be sun-dried for several days to let the chlorine in the water escape before watering.
Wastewater changed from a goldfish tank contains a certain amount of fertilizer and is very beneficial for watering stumps. Laundry water containing soap, water containing saline-alkaline substances, and chemically polluted water must absolutely not be used to water stumps.
3. Watering depends on weather changes: in summer, the weather is changeable. In sunny, hot, and dry weather, potted stumps have a large water requirement. Besides watering thoroughly once each morning and evening, around noon you should supplement with spraying and watering. Besides spraying the leaf surface, pot surface, and stump body, the ground of the potted stump should also be sprayed frequently to maintain air humidity around the pot, to prevent yellow leaves, dry leaves, and scorched leaves in the potted stump. Do not water on continuous rainy days, and there must be no water accumulation in the pot, to prevent long-term water accumulation from rotting the root system and causing the death of the stump.
4. It depends on the size, depth, and material of the bonsai pot: for tree stumps in small and shallow pots, water more frequently. For large and deep pots, the potting soil contains more water and it cannot evaporate through all at once, so water less frequently accordingly. Clay pots have good water permeability, the potting soil evaporates easily and dries easily, so water more frequently and in larger amounts. For ceramic pots, stone pots, glazed pots, and plastic pots, the pot walls are not breathable or permeable, and the potting soil does not dry easily, so watering should be differentiated according to the pot material. Making small bonsai is suitable in spring and autumn. At this time plants grow slowly, water evaporation is low, metabolism is relatively weak, and the survival rate is relatively high.
The material source for making small bonsai can be purchased from flower and tree shops or nurseries, or you can use wild small plants from mountain slopes and gullies, such as: Serissa japonica, Nandina domestica, Chinese wolfberry, elm, bamboos, etc. After digging them back and planting them in pots for one year, they can be used for making bonsai after repotting.
Beginners can start with forest-style bonsai, selecting several varieties of different heights, thicknesses, density, and forms, such as: boxwood, pond cypress, elm, golden larch, bamboos, etc. They can be planted singly or in groups, but the styling must have some variation and not stick to one pattern. The layout should alternate density and sparseness, with high and low staggered, with emptiness and solidity, balanced left and right, so that the layout is natural, in order to compose a three-dimensional picture. Then add a few stones of different sizes and small grasses, and it becomes a feeling of "open wilderness forest."
After initially getting started, you can gradually train tree stumps into bonsai by pruning. Its shaping methods are generally divided into two kinds: the wiring method and the pruning method. ① Wiring method: following the plant's ecological habits, through winding with metal wire to make it into a unique form and achieve an artistic effect, this is called the wiring method. Materials suitable for the wiring method include: five-needle pine, Luojiji, galanum, Caragana sinica, black pine, etc. ② Pruning method: according to the plant's growth characteristics, through pruning and trunk truncation, controlling the growth direction of its branches and buds and the length of branches, making it into a unique form, this is called the pruning method. Materials suitable for the pruning method include: Sageretia thea, Nandina domestica, Pyracantha, maple, plum, peach, etc.
For small bonsai, rainwater is suitable for watering. If using tap water, it is best to store it for two or three days to let the chlorine in the water volatilize before use. In spring and autumn, water once each morning and evening; during the plum rain period, avoid heavy rain washing to prevent lodging and affecting growth; when summer temperatures are high and the air is dry, prevent heat and lower temperature, and increase the frequency of spraying and watering; in winter, bonsai should be placed indoors. To do a good job of keeping warm and preventing freezing, watering should be reduced, and it is appropriate to keep it drier than usual. The water temperature should preferably be close to room temperature.
Because small bonsai have small pots, if fertilizer is not applied in time, it will cause early decline of tree vigor or branch withering. Therefore, around Qingming Festival, before the plant sprouts, you can first apply a thoroughly rotted thin liquid fertilizer once using the pot-soaking method. For foliage-viewing bonsai, apply fertilizer liquid mainly of nitrogen; for flower-viewing and fruit-viewing bonsai, apply more phosphorus and potassium fertilizer liquid; for pine and cypress bonsai, applying base fertilizer once a year is enough. During the plum rain season, because temperature and humidity conditions are suitable, potted plants easily send out new branches and tender leaves and grow extremely fast. Therefore, supplementing fertilizer for potted plants is very important. In this way their branches and leaves can maintain growth. In addition, fertilizing is suitable on sunny days when the potting soil is relatively dry, so that the fertilizer is not easily lost. As for the amount of fertilizer, it can be determined according to specific requirements. For small bonsai mainly for flower viewing, after flowering continue applying thin liquid fertilizer to keep next year's flower buds numerous and plump; for fruit-viewing varieties, it needs to be thicker, and apply a light fertilizer once before and after flowering to maintain nutrient supply and help increase the fruit-setting rate; among deciduous miscellaneous bonsai, except for those growing too weakly, generally it is not suitable to apply too much fertilizer, otherwise it will cause excessive vegetative growth and affect the beauty of the posture.
Pruning and pinching. Summer is the growth period of tree-stump bonsai. Plants grow quickly and have strong sprouting ability, which often affects the perfection of their form. Therefore, pruning and pinching work must be carried out.
For plants with particularly strong sprouting ability, such as Serissa japonica, Sageretia thea, elm, etc., pruning five to six times a year is required to maintain their graceful posture; Podocarpus macrophyllus is pruned once each in about June and October; five-needle pine, when replacing new leaves in April, not only must over-dense tender branches be cut off, but pinching must also be done, removing 1/3 of the new buds; black pine and Huangshan pine can have all main buds removed when new buds appear, leaving the newly grown secondary buds; after boxwood and golden larch sprout, leave one to two nodes and pinch, making them sprout more, then pinch again. In this way, their branches can be numerous and short, maintaining a graceful form.
For flower-viewing and fruit-viewing varieties, such as Malus halliana, Chaenomeles speciosa, Pyracantha, etc., more flowering branches should be retained, generally retaining 1-2 nodes per flowering branch; pomegranate is a bonsai for both flower and fruit viewing and also grows very vigorously, so more buds should be removed and branches pruned; for winter jasmine, plum, peach, etc., after flowering the short branches and thin branches should be trimmed away so that they sprout robust new branches again; for Sabina chinensis, from late May to early July cut off dead branches under the crown, and remove by hand the tender branches protruding beyond the crown, making the crown neat and full.
For deciduous varieties of tree stumps, after leaf fall, remove drooping branches, excessive growth branches, crossing branches, overlapping branches, diseased and insect-damaged branches, etc., so that the layers are distinct and beauty can be maintained.
For cypress and pine plants, pruning should not use scissors, otherwise the healed wounds will develop rust-colored spots; they should be removed by hand. For pruning forest-style bonsai, the integrity of the group should be considered to benefit viewing.

Bonsai is a kind of ingenious skill in flower art. Its careful maintenance is very important, and the position of autumn management is also an important part of the year.
Watering: Watering is the most basic and also the most important part of autumn management of tree-stump bonsai. In autumn the air is dry, and there is little soil in bonsai on courtyards and balconies, so if you are not careful it dries up. Watering too much can also cause excessive growth of branches and leaves, consuming too many nutrients. Rot of the root system in the bonsai leads to the death of the whole plant. So you must make sure not to water when not dry, and when watering, water thoroughly. Water less for coniferous trees and more for broadleaf trees; water less for clayey soil and more for sandy soil. It is suitable to water in the morning and evening, and avoid watering facing the sun at noon; avoid incomplete watering; avoid water temperature being too high or too low.
2. Placement environment: In autumn, bonsai should be placed in a place with air circulation and sufficient light. Coniferous trees and deciduous broadleaf tree stumps mostly like sun, such as five-needle pine, black pine, plum stump, pomegranate, etc. Evergreen broadleaf trees are relatively shade-loving, such as rhododendron, boxwood, Podocarpus macrophyllus, etc. Shade-loving ones should be placed in semi-shade for cultivation, and shallow pots or small pots especially need shading and moisture retention. Sun-loving plants absolutely must not be exposed to the sun either; they should be placed at the edge under trees, with more light.
3. Shaping. This refers to the method of achieving a desired plant shape by removing part of the terminal buds, lateral buds, leaves, and branches. Some remove terminal buds to promote lateral branch growth; some remove or retain adventitious buds sprouting from the base of the stump and trunk to make the plant shape beautiful; some, in order to appreciate new leaves, promote the tree to sprout two to three times a year by leaf removal. For example, maple leaves are removed in dog days, and by late autumn the leaves are red like fire. After Chinese wolfberry is defoliated twice in early summer and early autumn, in early winter green leaves and red fruits complement each other. Branch pruning is to obtain an ideal tree shape, or to facilitate light and air penetration and promote healthy growth.
4. Fertilizing: In principle, one is fully rotted and the second is thin. That is, the liquid fertilizer applied must be fully rotted. Fertilizer that is too concentrated will cause branches and leaves to grow too densely and vigorously, which is not conducive to overwintering. In addition, do not fertilize on rainy days or when the potting soil is too wet, and avoid splashing fertilizer liquid on branches and leaves.

Complete guide to orchid cultivation techniques

"Three parts planting, seven parts care," this is the ancients' experience in growing orchids. Whether care is good or bad determines whether orchids flourish and whether they can bloom, so the fact that predecessors attached great importance to this is reasonable. Below is a specific introduction to methods for caring for and managing orchids.

I. Location

The location where orchids are placed is very important, as it directly affects the growth and development of orchids. Orchids are generally placed in open ground in spring, summer, and autumn (in summer placed in a shaded spot in open ground), and placed indoors in winter. Outdoors it is best to have open surroundings and moist air. Indoors there must be sufficient light, preferably facing south. In this way, orchid growth is benefited. Orchid pots are best placed on wooden shelves or tables, not on the ground.

II. Shading

Orchids mostly belong to semi-shade plants, and most species are afraid of direct sunlight and need appropriate shading. In early and mid-April, orchids can receive more sunlight to promote growth. After late April, appropriate shading is needed. For summer orchids and autumn orchids with upright leaves, it is best to place them on the south side of a shaded area so they receive appropriately more sunlight; for drooping-leaf autumn orchids and spring orchids, receiving two hours of light per day is best. From the beginning of June to September, shading should be started earlier each day. If using reed blinds, dense blinds or two layers of sparse blinds can be used. After October, the weather turns cooler and sunlight is weaker, so shading can be delayed, but around noon attention must still be paid to doing shading work well.

III. Rain protection

Orchids can be exposed to light rain, but must avoid plum rains, showers, or continuous rain. During the plum rain season, especially, rain protection work must be done well. From late June to mid-September, there are often showers. If the rain time is short and the rainfall is also small, more watering should be done in the evening to let the hot air in the pot escape, otherwise orchids will be damaged, or even root rot and death will occur. If a shower is followed by sunshine, shade must be provided in time, so that the rising hot air from the ground does not affect orchid growth. The rainy season coincides with the stage when orchids send out leaf buds. If the potting soil is too wet, it will cause poor leaf bud growth or invite disease. At this time, a small amount of plant ash can be sprinkled to regulate the humidity of the potting soil.

IV. Watering

A flower proverb says: "Dry orchids, wet chrysanthemums." This saying has some truth. Generally speaking, for orchids, eight parts dry and two parts wet is best. If too wet, it easily causes the flower to rot at the root and die. The principle of watering should be: water when dry, stop when wet, and appropriately lean dry. In specific practice, generally pay attention to: during the growth period (May to the end of June) water appropriately more, during the leaf bud emergence period (about March-April) and flowering period (about March-April) water appropriately less, and during the dormant period (winter), water even less or not at all. If the flower pot is large and the orchid plant is small, water less; if the pot is small and the plant is large, water more. When the climate is hot and dry, water appropriately more; when cold and humid (such as the plum rain season, etc.), water less or not at all. For orchids newly dug from the mountains, if the root system is sparse or many roots are broken, water less and keep the potting soil a bit dry, so that root rot does not occur and new leaf growth is favored. The ancients' experience of "not dry in autumn, not wet in winter" is a very good summary of how to water spring orchids and summer orchids. But in some northern regions, because the climate in winter and early spring is too dry, orchids should not be made too dry either. Watering time: in summer and autumn, water after sunset so that the orchid leaf surface dries before nightfall, or water in the early morning; in winter and spring, water around sunrise. Do not suddenly water with cold water after burning sun exposure, so as not to lower the soil temperature, affect root water absorption, and disturb physiological balance. The amount of water should not be too large, to help suppress disease occurrence.

Watering method: water should be poured in from the edge of the pot, and must not be poured into the flower buds, to avoid causing rot.

Predecessors had very good summaries of experience in watering orchids. For example, Yu Zhao in "Record of Orchid Cultivation at the Capital Gate" proposed different watering methods according to the twenty-four solar terms within a year. The following is an excerpt for reference. But two points need attention: first, "Record of Orchid Cultivation at the Capital Gate" uses Beijing's climate as the standard; second, the months in the text refer to the lunar calendar rather than the Gregorian calendar, for example "first month" is actually February in the Gregorian calendar.

1. Start of Spring, Rain Water: spring orchids have already set flowers, the soil should not be too dry, slightly moisten along the pot edge; if the autumn orchid pot has not dried to the bottom, do not water.

2. Awakening of Insects: when the spring orchid pot has dried to half the pot (empty above, solid below), it can be moistened with water, but not too much; autumn orchids same as before.

3. Spring Equinox: spring orchids have finished flowering, avoid moisture; when the pot is half dry, it can be moistened with water.

4. Clear and Bright, Grain Rain: do not let the potting soil become too dry; moisten with water every 5 days.

5. Start of Summer: orchids begin to be moved out of the room; it is suitable to water thoroughly once.

6. Grain Full: the potting soil should not be too dry or too wet. Spots appearing on the leaves means it is too wet; new buds with withered tips means it is too dry. Water one sheng every 4 days (about a dry teacup), so that the potting soil is moist from the bottom up to 2/3.

7. Grain in Ear: the climate is dry, and even more attention should be paid to not being too dry or too wet.

8. Summer Solstice: the potting soil should not be too dry. If there is heavy rain, it can only endure one day. If there is continuous overcast rain, the pot needs to be moved to a ventilated place.

9. Minor Heat: at this time the air is too humid, and the potting soil must not be too wet. The pot should be placed in a ventilated place. If it is dry and hot with little rain, water one sheng every 2 days. After heavy rain or one heavy wetting, you must wait until the potting soil is dry to 2/3, otherwise it is not suitable to water again.

10. Major Heat: the potting soil easily dries all the way through, and attention should be paid that only one heavy rain or one heavy wetting per day is suitable.

11. Start of Autumn: orchids need water at this time, requiring 2 sheng of water every 3 days, and it is also suitable to shelter from wind.

12. End of Heat: water once every 5 days. Except for continuous haze and rain, they can be allowed to receive rain and dew.

13. White Dew: autumn orchids need frequent watering even more than spring orchids, but after being wet they must dry greatly before they can be wetted again.

14. Autumn Equinox: if autumn orchids have already produced flowers, watering should be slightly less; if they have not produced flowers, watering should be slightly increased.

15. Cold Dew: autumn orchids should be watered thoroughly; spring orchids should not be watered thoroughly but should be moistened.

16. Frost's Descent: orchids should be moved indoors, the watering time changed to midday, and after watering they need to be placed in the midday sun for 1-2 hours.

17. Start of Winter: only moistening with water is suitable, about half a sheng every 5 days.

18. Minor Snow: the flower room should avoid warmth, and should not be too humid. If too humid, it can cause root rot, scarred leaves, and even withering. If the pot has not dried to the bottom, only slightly moisten the soil surface.

19. Major Snow: autumn orchids do not need water; spring orchids should be slightly moistened.

20. Winter Solstice: neither should be irrigated.

21. Minor Cold: watering is avoided for both.

22. Major Cold: autumn orchids still do not need water; spring orchids can be slightly moistened with water.

V. Fertilizing

Whether to fertilize orchids depends on the orchid's growth condition. Those growing luxuriantly and without disease can be fertilized; those growing poorly should not be fertilized or should be fertilized only a little. For orchids newly dug from the mountains, before new roots develop, absolutely do not use fertilizer. They need 1-2 years of cultivation, and only when the new roots are vigorous can fertilizer be applied, otherwise they easily wither and die.

Generally speaking, in June-July, when orchid leaf buds extend to about 1.5 cm, 1-2 applications of thin rotted liquid fertilizer can be given (chemical fertilizer is not suitable), but fertilizing is not suitable in high-temperature seasons. In August-September, apply 1-2 more applications of rotted thin liquid fertilizer. For plain-heart orchid varieties, 1-2 applications of plant ash extract can be given, with very good results. The best time to fertilize is in the evening, and the next morning water once with clear water.

A relatively simple way to tell whether orchids need fertilizer is to look at the depth of leaf color. Leaves that appear yellow and thin indicate fertilizer deficiency, and topdressing should be applied; leaves that appear black with scorched leaf tips indicate too much fertilizer, and fertilizing should be stopped.

For fertilizer, you can use the various methods introduced above to make fertilizer yourself. When applying these fertilizers, they need to be diluted with 8-9 times water, and must not be too concentrated. When fertilizing, apply it to the root zone of the plant, and absolutely do not apply it to the leaf surface. The main fertilization times and dates for orchids: times, dates, category, first time, second time, third time, fourth time, notes

Spring orchid category: late June, mid-July, mid-August, early September. The fourth time must be especially thin.

Summer orchid category: late June, mid-July, mid-August, early September. The fourth time must be especially thin.

Autumn orchid category: early June, late June, late July, mid-August. The fourth time must be especially thin.

VI. Pruning

In orchid cultivation, pruning must be carried out continuously. When old leaves turn yellow, they should be cut off in time to facilitate ventilation. Some leaves whose tips have dried should also be cut off. In particular, leaves damaged by disease and insects need to be removed in time to avoid contagion. When cutting off leaves with viral disease, the scissors used should not be used again to cut disease-free leaves, to prevent virus transmission. If the same pair of scissors is used, it must be disinfected. For precious orchids, after flower buds emerge from the soil, if there are too many flower buds, keep the strong buds and remove the rest of the thin and small flower buds; leaving 1-2 flower buds per pot is suitable. If there are too many flower buds, it will not only make the current year's flowers bloom poorly, but also consume too much of the mother plant's nutrients and affect next year's flowering. Generally orchids do not need flower buds cut off. Spring orchid flowers bloom for about half a month, after which the flowers need to be cut off; for summer orchid flowers, when the last flower on the inflorescence has been open for one week, the inflorescence should also be cut off. Precious varieties should not be allowed to pollinate and set seed, otherwise next year's flowering will be affected. If used for hybrid breeding, then they need extra careful cultivation to make the fruit plump and mature.

VII. Cold protection

Autumn orchids should do cold protection work early. If the temperature is 2-3°C, they can be moved indoors. Cold orchids, growing in the south, need even earlier cold protection. Spring and summer orchids have relatively strong cold resistance, but if freezing occurs they must also be moved indoors in time. If the room temperature can be maintained at 1-2°C, they can overwinter. If a severe cold current strikes and the room temperature drops below zero, heating must be carried out in time; generally it is enough to keep the room from freezing. Indoors, autumn orchids should be placed on the south-facing side, and spring and summer orchids on the other side. Around noon, windows should be opened for ventilation on the south and southeast sides (for autumn orchids on overcast days at 1-2°C, windows must not be opened, to prevent cold wind from blowing in and freezing the leaves). Autumn orchids like to be somewhat dry in winter, while the potting soil of other orchids should remain moist.

VIII. Flower removal

For orchids growing poorly, with few leaves per clump, or with poor roots, flower removal should be carried out. For relatively good varieties, spring orchids can appropriately have 1-2 flower buds removed; for summer orchids, when the flower buds have extended, keep 1-2 flower buds and remove the rest. In this way the flowers can bloom longer, more new leaves can be sent out, and old leaves are less likely to wither and die. Precious spring orchid flowers should be removed after blooming for 3-5 days, so that leaf buds grow robustly; when the topmost flower of a summer orchid has opened, it can also be cut off at cm from the pot surface.

IX. Flood prevention

If the cultivation site has open surroundings and relatively high terrain, when strong winds or typhoons pass through in summer, wind protection work needs to be done well, to prevent the leaves of summer orchids or cold orchids from being broken and damaged.

X. Mist spraying

In dry seasons, spray mist every evening on the balcony where potted flowers are placed, mainly to make the ground moist and increase air humidity. The pot surface of orchids should also be sprayed with mist. When spraying mist, spray upward so that the mist droplets fall finely and evenly and the leaf surface is moistened. This can promote good orchid growth and give the leaf surface a glossy appearance.

XII. Pest and disease control

Sterilization treatment should be carried out (exposure to the blazing sun is enough) to prevent disease occurrence. Orchids are most prone to southern blight in rainy and high-temperature seasons, and thiophanate or Bordeaux mixture at 800 times dilution can be sprayed for prevention. If the disease is severe, thiophanate at 500-750 times dilution can be used, sprayed once every 7-10 days. Among insect pests, scale insects occur most. This insect attaches to the base of the leaves. If scale insects are found, they should be removed in time. To avoid scale insect infestation, starting in April, "1059" at 2000 times dilution can be used for control. In order to suppress the occurrence of orchid diseases, besides properly controlling the dry and wet degree of the potting soil at ordinary times, you should also use as many clay pots and as few glazed pots as possible in pot selection. Especially for poorly growing orchids newly dug from the mountains, clay pots must be used for planting. Doing this makes the potting soil dry easily, which can promote orchid growth and reduce disease occurrence

How should orchids be grown well?

1. Potting soil requirements: neutral to slightly acidic soil containing a large amount of humus, loose, and with good drainage is best. The pH value is generally around 5.5 to 6.5. In Sichuan, Emei Xiantu and "Xinghong brand" refined orchid planting material are mostly used, and more commonly "bamboo root mud" and leaf mold from broadleaf forests in mountainous areas are used to cultivate orchids.

2. Placement location: orchids can be cultivated outdoors and on balconies in spring, summer, and autumn. Choose a place with good ventilation, moist air, and no environmental pollution. Being near a pond or riverside is of course good, but at least there should be tall trees or bamboo groves and shade nets to reduce sunlight exposure and lower temperature. Orchid pots are best placed on wooden shelves (or steel shelves). If placed on the ground, bricks should be used as a base. For home balconies, a small galvanized iron water basin can also be used to store water with bricks placed on it for cultivation, increasing humidity.

3. Appropriate shading: orchids mostly belong to semi-shade plants, and most species are afraid of direct sunlight and need appropriate shading. In early and mid-April, orchids can have the net removed and windows opened, receiving more sunlight to promote growth. In May, besides the midday sun, they can receive 6 hours of light; starting in June, shade all day; after October, besides midday, they can be fully opened for care. Remember the proverb: "More shade gives good leaves, more sun gives good flowers."

4. Reasonable fertilization: orchids are originally "vegetarian," and fertilizing depends on the selected potting soil and growth condition. Those growing luxuriantly and without disease can be fertilized; those growing poorly should not be fertilized or should be fertilized only a little. For newly planted orchids whose roots have not fully developed after potting, only after 1-2 years can fertilizer be applied. Generally in June-July, when orchid leaf buds extend to about 1.5 cm, apply rotted liquid fertilizer once every three weeks (a thin concentration of 10% is suitable). Avoid chemical fertilizer. If high-temperature seasons occur, fertilizing is not suitable. In August-September, apply diluted liquid fertilizer once every two to three weeks. Each fertilization of orchids is best done in the evening, and in the morning water with clear water, called "return water."

5. Appropriate watering: for orchids, rainwater and spring water are best for watering. Tap water or rice water needs to be used after standing overnight. When watering, pour from the pot edge, and do not pour into the flower buds. The amount of water should be determined according to air temperature, the dry and wet degree of the potting soil, and the growth condition of the orchid. Water more for large leaves and less for fine leaves. In April-May, before new buds have emerged from the soil, the potting soil should be somewhat dry; if too wet, new buds easily rot; June-September is the growth period of new orchid buds, and the amount of water should be increased. On sunny days, water once each early morning, and absolutely avoid watering under the blazing sun at noon. In autumn, reduce the amount of water as appropriate, and leaf-surface misting can be used to keep the potting soil moist. In winter, water should be controlled even more, keeping "eight parts dry, two parts wet" as suitable.

6. Evening misting: orchids originally grow in a moist-air environment, so in dry seasons, besides shading, mist must also be sprayed in the evening to increase air humidity and lower temperature; water can also be poured on the ground (table surface) where potted orchids are placed. "One cold and one hot" can even more stimulate orchid growth.

7. Wind and rain protection: "February ghost wind" and old leaves turning yellow and receding are normal phenomena, and withered branches and fallen leaves can be cut off. Orchids can be exposed to light rain, but avoid plum rains, rainstorms, or continuous rain, otherwise the heart and leaves easily rot. In rainy seasons, a small amount of plant ash can be sprinkled appropriately.

8. Pruning and flower removal: in orchid cultivation, withered, yellow, broken leaves and diseased leaves should often be cut off. To facilitate ventilation. For precious orchids, if there are too many flower buds, keep only the strong buds, and 1-2 flower buds per pot is suitable. Spring orchid flowers should be removed half a month after blooming; precious orchids should be removed after 7 days, so that spring orchid leaf buds grow robustly and bloom better next year. When the last flower on a summer orchid inflorescence has been open for one week, cut it off at 3 cm from the pot surface.

9. Cold protection and warmth: because orchid varieties differ, their places of origin vary, and their cold resistance also differs, so the time for moving them indoors in winter and their indoor placement also differ. Cold orchids, autumn orchids, and New Year orchids grow in the south, and are suitable to be moved indoors when the temperature is 5°C (or close the windows and surround with netting), and placed as much as possible in a south-facing sunny spot. Spring and summer orchids have strong cold resistance, and can be moved indoors only when the temperature reaches 0°C, placed on the northeast side. Around noon on sunny and windless days, windows should be opened on the south or southeast side, and nets pulled open for ventilation. Autumn orchids on sunny days at 1-2°C must not have windows opened. Of course, if there is a greenhouse, electric light heating can be used.

10. Disease and pest control: the potting soil generally needs sterilization treatment (exposure to blazing sun also works) to prevent disease occurrence. Orchids are most prone to southern blight in rainy and high-temperature seasons. For a small amount, it can be brushed off with a wet cloth; for many pots, Bordeaux mixture or thiophanate at 500-800 times dilution can be used, sprayed once every 7-10 days. Among pests, scale insects (commonly called "orchid lice") occur most. During the hatching period, use 1% omethoate and 25% phosmet emulsifiable concentrate at 1000 times dilution, sprayed once a week. To treat the symptoms you must treat the root cause. Pots should be arranged with appropriate density and placed high and low to increase air permeability and ventilation and reduce disease occurrence.

(II) Ecological habits of orchid cultivation

Orchids originated in our country. They like warmth and humidity, and especially warm winters and cool summers are most ideal. High temperature and dryness must be avoided. In winter, it is best if it does not freeze, and maintaining 3°C-7°C is most suitable. In summer, 25°C-28°C is suitable. In natural distribution, orchid production areas are near streams and gullies, receive rain and dew all year round, and require annual rainfall of more than 1000 mm. They require deep upper soil, rich in humus, dark brown, loose and fertile, with good water permeability and water retention, slightly acidic soil, pH 5-PH 6.5, and avoid water accumulation.

Orchids like shade and require short sunshine duration. In natural distribution, it is shown that spring orchids require tree shade canopy density of 0.7-0.95; Cymbidium faberi requires 0.5-0.8, with light duration slightly longer than spring orchids; Cymbidium ensifolium, Cymbidium sinense, and cold orchids also require large canopy density shading. Cymbidium plants have the habit of dormancy in their native areas, which depends on the rainy season and dry season. Usually the dry season is in winter, which is the dormant period of orchids, and the rainy season is in spring and summer, which is the growth period of orchids, when they can continuously send out buds and bloom.

(3) Propagation methods for orchid cultivation Orchids are commonly propagated by division, sowing and tissue culture.

1. Division This can be done in both spring and autumn, generally once every three years. Any plant that grows vigorously with densely clustered pseudobulbs can be divided, and after division each clump must retain at least 5 pseudobulbs connected together. Before division, reduce watering so that the potting soil is fairly dry. When potting up after division, first cover the drainage hole at the bottom of the pot with a broken tile, then spread coarse gravel to occupy 1/5 to 1/4 of the pot's depth, then add coarse-grained soil and a little fine soil, and finally plant in sandy loam rich in humus. The planting depth should be just enough to bury the pseudobulbs in the soil, leaving a 2 cm rim at the edge of the pot, topped with Selaginella or fine gravel, and finally water thoroughly, place in shade for 10-15 days, keep the soil moist, gradually reduce watering, and carry out normal care.

2. Propagation by sowing Orchid seeds are extremely fine, containing only one incompletely developed embryo, with very low germination capacity; moreover, the seed coat does not readily absorb water, so sowing by conventional methods will not germinate them. Orchid mycorrhiza or an artificial culture medium is therefore needed to supply nutrients before germination can occur. For sowing, it is best to select fruit that has not yet split open; after sterilising the surface with 75% alcohol, remove the seeds, soak them in 10% sodium hypochlorite for 5-10 minutes, take them out and rinse 3 times with sterile water, then sow them in culture bottles containing culture medium, and place them in a dark culture room, keeping the temperature at about 25C; after they begin to sprout, move them into the light and they will form protocorms. From sowing to transplanting takes six months to a year. Tissue culture has already been successful, and where conditions permit this method can be used for propagation.

(4) Cultivation techniques for orchids

1. Site selection The site should be open on all sides, well ventilated, close to water, with moist air and no coal-smoke pollution. On the southwest side of the site, evergreen broadleaf trees can be planted, with a canopy density of about 0.7, which reduces afternoon sunlight and helps regulate humidity and temperature.

2. Watering Rainwater or spring water is preferable; water containing salt and alkali should not be used. If tap water is used, it should be left to stand for several days before use. Watering depends on the temperature: in spring the amount of watering should be small, in summer it should be greater; during the plum rain season, when orchids are putting out leaf buds, the potting soil should be kept slightly dry; after autumn when the weather turns cool, reduce the amount of watering and simply keep the soil moist. In winter, keep the plants dry indoors, reduce the frequency of watering, and water at midday. Orchids can tolerate light rain, but continuous rain or heavy rain easily causes rot of the heart and leaves, so protection from rain must be attended to.

3. Fertilising For orchids, cake fertiliser is suitable: mix 4 parts plant ash, 10 parts bean cake and 10 parts bone meal evenly, place in a crock, add water several times until the bean cake is soaked and swollen, then cover and seal, let it decompose for one year, and then make it into dry granules. When using, simply place on the surface of the pot. If whole manure is used, it should also be decomposed for one year, then diluted with water, filtered and used. Generally, fertilising begins in May and stops at the Beginning of Autumn, following the principle of frequent applications of weak fertiliser. Fertilising should be done in the evening, and the next morning water once with clear water.

4. Shading and cold protection Except in early spring and winter, the plants should be kept under open-air frames. The shade frame requires good ventilation. When orchids have just been brought out in March to April, they can be given more sun, and afterwards the shading time is gradually increased. In winter, orchids must be moved indoors for protection from the cold, with the room temperature kept at 1C-2C. In addition, after orchids are brought out in spring and before they are brought in in autumn, attention must also be paid to protection from frost.

5. Pest and disease control The main pests and diseases of orchids are:

(1) Southern blight: occurs mostly during the plum rain season. Prevention should focus on ventilation and light penetration and good drainage of the potting soil. After the disease appears, the infected potting soil can be removed and quintozene powder or lime sprinkled on.

(2) Anthracnose: present all year round, and more rampant in hot, rainy seasons. In addition to improving environmental conditions, control methods include spraying with a 800-1500 times dilution of 50% thiophanate-methyl wettable powder at the onset of the disease, once every 7-10 days, then supplementing with 1% Bordeaux mixture of equal parts, once every half month.

(3) Scale insects: they reproduce fastest under hot, humid conditions with poor air movement. Use conventional control methods.

In summary, to grow orchids well one must understand their natural growing environment, take reasonable measures and strengthen care and management. According to the "Orchid Growing Formula": "Do not bring them out in spring, do not sun them in summer, do not keep them dry in autumn, do not keep them wet in winter" - this is a summary of China's orchid-growing experience.

A brief discussion of the rational use of pesticides for orchids

Fungicides are agents for preventing and controlling crop diseases. When we normally control orchid diseases, we must choose according to the different properties and modes of action of different categories of fungicides. One category is protective fungicides, whose function is to treat plants or the environment in which plants grow before the pathogen invades. They need to be used before the plant comes into contact with the pathogen or before disease occurs in order to be effective, such as Bordeaux mixture, lime sulphur, mancozeb, zineb, etc. There is another category, therapeutic fungicides, which we encounter frequently; their characteristic is that they are systemic. The use of such fungicides is when the pathogen has already invaded the plant body or the plant is already diseased, and at this point they are applied to reduce or eliminate the plant disease. Applying the agent in the early stages of the disease gives a better effect.

The onset and peak stages of different pathogens also differ, being greatly influenced by the external environment, especially by the growth and development status of the infected crop and by temperature and humidity, (therefore, we must grow strong orchid plants). When controlling diseases, it is better if one can be familiar with the living habits and epidemic patterns of the pathogenic organisms; disease control can then be carried out according to different seasons and temperature environments, which plays a huge role in the effective exertion of the pesticide's efficacy. The crop diseases caused by various pathogens differ, and the disease symptoms are also markedly different, so when choosing fungicides one must prescribe the right medicine for the illness. Moreover, the efficacy should be significant and lasting; one should not blindly pursue high efficiency, broad spectrum or even "all-purpose" agents - as if, whatever the disease, one single agent can handle it all. This is certainly not workable. When using agents, attention should be paid to preventing the development of pathogen resistance, that is, one must not use the same fungicide continuously, nor use the same category of fungicide several times in succession during one growing season; the number of applications of systemic agents especially should be limited. For example, in production, systemic agents can be used in combination or in rotation with chlorothalonil, mancozeb, etc.

In our daily use of agents, we should adopt corresponding control measures according to the patterns of pathogen infection. When using fungicides to spray directly on orchid plants, attention should be paid to the influence of natural conditions, to prevent loss of efficacy or phytotoxicity. When temperature and humidity are high, the concentration of the agent used can be appropriately reduced; for agents that readily decompose or volatilise under strong light, application should be carried out on cloudy days or in the evening. Different pesticides each have a certain scope of use; only by understanding them deeply and mastering their characteristics of use can one correctly select pesticides and achieve twice the result with half the effort. Carbendazim is a systemic fungicide commonly used by everyone; it can control dozens of fungal diseases, and ascomycetes and deuteromycetes are especially sensitive to it, but it is ineffective against bacteria and against diseases caused by oomycetes among the fungi. Therefore, when a plant has been definitively diagnosed as infected with a fungal disease and repeated use of carbendazim is ineffective, one should consider switching to a phenylamide pesticide (such as metalaxyl); this category is mainly used for downy mildew, phytophthora blight and pythium rot caused by oomycetes, while its effect on diseases caused by other fungi and bacteria is very poor. Chlorothalonil is a non-systemic broad-spectrum fungicide with a preventive effect on many plant fungal diseases; it can block the germination of pathogen spores, hinder mycelial development and spore formation, and can control diseases that have developed resistance to carbendazim, but its control effect on diseases caused by soil-borne Pythium is poor. Therefore, often change the fungicide, (Huakang is claimed to kill all diseases, I do not know whether it is true; when I use it I dare not be careless and still mix it with other fungicides), striving to protect the orchid plants to the greatest extent and spare them the torment of disease. When the orchids grow healthily, orchid growers are happy too.

Figure 1 Ring spot disease + anthracnose (Colletotrichum)

Ring spot disease + anthracnose (Colletotrichum) routine preventive applications:

Pesticide name: 77% Kocide wettable powder; mode of action: broad-spectrum protective fungicide; method of use: 1000 times dilution / 3-4 applications / 7-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: brown spot disease, anthracnose, leaf spot disease, ring spot disease, bacterial brown spot disease;

Pesticide name: 25% Sportak emulsion; mode of action: broad-spectrum fungicide; method of use: 1500 times / 2-3 applications / 8-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: anthracnose, leaf spot disease, sooty mould, black spot disease, round spot disease, ring spot disease;

Pesticide name: 80% mancozeb wettable powder; mode of action: broad-spectrum protective fungicide; method of use: 800 times / 3-4 applications / 6-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: anthracnose, leaf spot disease, sooty mould, black spot disease, round spot disease, ring spot disease;

Ring spot disease + anthracnose (Colletotrichum) supplementary notes:

1. Because most of the control prescriptions for anthracnose are of the emulsion or mancozeb type, when using them one must pay attention to the weather temperature and the UV index.

2. When the temperature exceeds 30 degrees, avoid using emulsion and copper agents as far as possible; when the UV index is too high, choose to apply the agent before 5 a.m. or after 6 p.m. as far as possible.

3. It is suggested that during normal application one may choose to mix two prescription fungicides for use, so that treatment and defence can be carried out in multiple aspects.

Figure 2 Ring spot disease + leaf spot disease

Ring spot disease + leaf spot disease routine preventive applications

Pesticide name: 80% mancozeb wettable powder; mode of action: broad-spectrum protective fungicide; method of use: 800 times / 3-4 applications / 6-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: anthracnose, leaf spot disease, sooty mould, black spot disease, round spot disease, ring spot disease;

Pesticide name: 77% Kocide wettable powder; mode of action: broad-spectrum protective fungicide; method of use: 1000 times dilution / 3-4 applications / 7-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: brown spot disease, anthracnose, leaf spot disease, ring spot disease, bacterial

Ring spot disease + leaf spot disease supplementary notes: before the leaves of a diseased orchid have dried up, ring spot disease, if not carefully examined, is often taken for ordinary leaf spot disease or [...]. Treating [...] is [...]

2. It is suggested that during normal application one may choose to mix two prescription fungicides for use, so that treatment and defence can be carried out in multiple aspects.

Figure 3 Mild nutrient deficiency disease (zinc, magnesium, iron)

Mild nutrient deficiency disease (zinc, magnesium, iron) routine preventive applications: although this is a diseased state it is not contagious; during normal fertilising, supplement with some trace elements and fertilisers containing zinc, magnesium, iron and calcium. Mild nutrient deficiency disease (zinc, magnesium, iron) supplementary notes: during normal fertilising, supplement with some trace elements and fertilisers containing zinc, magnesium, iron and calcium.

Figure 4 Soft rot + black spot disease

Pesticide name: 72% agricultural streptomycin sulfate wettable powder; mode of action: antibiotic fungicide; method of use: 800 times / 2-3 applications / 7-day interval, spray, drench at the roots; can also prevent: bacterial brown spot disease, soft rot;

Soft rot + black spot disease supplementary notes: because this is a condition in which fungi and bacteria occur simultaneously, two different fungicides must be mixed for use. Since the two fungicides each have their own dilution concentration when mixed, this often troubles beginner orchid growers. Here is a supplementary explanation: ratio: 100 jin of water is needed; use the bacterial one, streptomycin sulfate at 500 times, mixed with the fungal one, carbendazim at 1000 times.

1. 100 jin of water at 500 times streptomycin sulfate means streptomycin sulfate needs to be added in an amount of 100 grams.

2. 100 jin of water at 1000 times carbendazim means carbendazim needs to be added in an amount of 50 grams.

3. That is, using 100 grams of streptomycin sulfate equals (500 times) + 50 grams of carbendazim equals (1000 times), put into 100 jin of water at the same time and mixed for use - only then is the pesticide dosage correctly prepared.

Figure 5 Leaf-tip anthracnose + leaf blight

Leaf-tip anthracnose + leaf blight routine preventive applications

Pesticide name: 25% propiconazole emulsifiable concentrate; mode of action: broad-spectrum systemic fungicide; method of use: 1500 times / 2-3 applications / 8-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: brown spot disease, round spot disease, anthracnose, leaf spot disease, leaf-tip blight;

Pesticide name: 10% Score water-dispersible granules; mode of action: broad-spectrum systemic fungicide; method of use: 3000 times / 2-3 applications / 8-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: brown spot disease, leaf spot disease, black spot disease, round spot disease, leaf blight, ring spot disease, leaf-tip blight, sooty mould;

Leaf-tip anthracnose + leaf blight supplementary notes: because this is a cross-symbiosis of two pathogens, it is suggested that using two fungicides is a relatively simple control. Regarding the mixing method of the two fungicides, to repeat once here: when two disease conditions occur simultaneously, two different fungicides must be mixed for use. Since the two fungicides each have their own dilution concentration when mixed, this often troubles beginner orchid growers. Here is a new supplementary explanation: ratio: 100 jin of water is needed; use the bacterial streptomycin sulfate at 500 times mixed with the fungal carbendazim at 1000 times.

1. 100 jin of water at 500 times streptomycin sulfate means streptomycin sulfate needs to be added in an amount of 100 grams.

2. 100 jin of water at 1000 times carbendazim means carbendazim needs to be added in an amount of 50 grams.

3. That is, using 100 grams of streptomycin sulfate equals (500 times) + 50 grams of carbendazim equals (1000 times), put into 100 jin of water at the same time and mixed for use - only then is the pesticide dosage correctly prepared.

Figure 6 Leaf-margin black spot disease

Leaf-margin black spot disease routine preventive applications

Pesticide name: 80% mancozeb wettable powder mode of action: broad-spectrum protective fungicide method of use: 800 times / 3-4 applications / 6-day interval, spray / underside of leaves, upper surface of leaves can also prevent: anthracnose, leaf spot disease, sooty mould, black spot disease, round spot disease, ring spot disease.

Pesticide name: 10% Score water-dispersible granules; mode of action: broad-spectrum systemic fungicide; method of use: 3000 times / 2-3 applications / 8-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: brown spot disease, leaf spot disease, black spot disease, round spot disease, leaf blight, ring spot disease, leaf-tip blight, sooty mould;

Pesticide name: 25% Sportak emulsion; mode of action: broad-spectrum fungicide; method of use: 1500 times / 2-3 applications / 8-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: anthracnose, leaf spot disease, sooty mould, black spot disease, round spot disease, ring spot disease;

Pesticide name: 50% Sportak wettable powder; mode of action: broad-spectrum fungicide; method of use: 2000 times / 2-3 applications / 8-day interval, spray / underside of leaves, upper surface of leaves; can also prevent: anthracnose, leaf spot disease, sooty mould, black spot disease, round spot disease, ring spot disease;

Leaf-margin black spot disease supplementary notes: in fact the fungicides used for many orchid leaf diseases are of similar nature, but as our professional introduction we have no choice but to present all the disease conditions for orchid growers to understand. In general fungicide selection, broad-spectrum and systemic pesticides of the two kinds are the best.

Experience-talk reminder: in my experience, the key work when buying pesticides is to choose the manufacturer's reputation and the stated ingredients, lest one has only the psychological comfort of having sterilised, when the result is fake pesticide ingredients, so that the disease is not brought under control and the golden time for treating the disease is missed.

Experience-talk reminder: the second cause of harm is this: thinking that these pesticides may not have enough of the specified ingredients, one instead increases the concentration and the dilution factor; who would have known that this time one had bought the real pesticide, and as a result, once the dilution factor was increased, serious phytotoxicity was caused. Ha ha! One can only look speechlessly to the heavens.

Figure 7 Blight disease

Blight disease routine preventive applications

Pesticide name: 72% Curzate wettable powder; mode of action: systemic fungicide; method of use: 1500 times dilution / 2-3 applications / 10-day interval, drench the root and stem; can also prevent: blight disease

Pesticide name: 50% Anke wettable powder; mode of action: systemic fungicide; method of use: 12500 times / 2-3 applications / 10-day interval, drench the root and stem; can also prevent: blight disease

Blight disease treatment supplementary notes:

1. At the peak of the disease, preventive medication must be continued persistently. Having understood the characteristics of stem rot, we can only use targeted fungicides

2. 72% agricultural streptomycin sulfate soluble powder at 800 times dilution, 77% Kocide powder at 1000 times dilution, spray the underside of leaves, upper surface of leaves and the crown

3. Mifenan (emulsion) 1500 times + tetracycline (powder) 2000 + dimethomorph (powder) 2000 times dilution, spray the underside of leaves, upper surface of leaves and the crown

4. Antaisheng 500 times + Mifenan 1500 times + streptomycin sulfate 500 times dilution, spray the underside of leaves, upper surface of leaves and the crown (when applying fertiliser or pesticide, one must spray the underside of the leaves, because plant absorption relies on the stomata on the underside of the leaves)

5. About every 20 days, use Dexon 800 times + tetracycline 3000 times dilution to thoroughly drench the roots.

6. Fungicides must be alternated and rotated so as not to produce resistance and delay the disease.

Basic principles of orchid cultivation and management techniques - orchid cultivation techniques

1. Preparation of growing medium Planting orchids requires a specially made growing medium, also called orchid mud. The growing medium for orchids should preferably be loose and air-permeable, with good aeration, an appropriate amount of fertiliser and no hidden pests or diseases. The composition of the growing medium is made from one or several basic components (substrates). These basic components include soil, fertiliser and other materials, of quite many kinds. Some components seem unrelated to soil, but all are substrates on which orchids rely to stabilise the plant and to grow and develop.

(1) Growing medium formulas.

In East China, orchid growers generally like to use orchid mud from Shaoxing, Yuyao and other places; in recent years Emei Pai Wangpai Xiantu has also been welcomed by people, but the quantity of these growing media is limited and the price is high, so they can only be used for repotting. For large-scale planting in the ground, hundreds or thousands of tons of growing medium are needed, so one can only use local materials. After years of practice and repeated screening, we determined that the best formula is: four parts yellow sandy soil, four parts sawdust, two parts river sand; if it is yellow loam, then one part river sand, one part sawdust, one part yellow loam. All are thoroughly mixed. The pH value of the prepared growing medium should be between 6.5-6.8; it is loose and air-permeable, with excellent water retention and aeration, and comprehensive nutrition. The river sand and sawdust serve to conduct water and air; the sawdust is decomposed by bacteria and can slowly release nitrogen, phosphorus, potassium, etc. Yellow loam also contains various trace elements. After years of observation, this formula is very suitable for orchid growth. It is especially suitable as a substrate for the domestication and cultivation of wild orchids; it suits Cymbidium goeringii and Cymbidium faberi, and is also ideal for Cymbidium ensifolium and Cymbidium kanran, with the flowering rate and stress resistance both increasing markedly.

(2) Bamboo root mud.

This refers to the soil at the roots of bamboo clumps that have been planted for many years. Because of the spreading growth of bamboo rhizomes and bamboo roots and the rotting of bamboo leaves and shoot sheaths, this soil has become loose in structure, well drained, and possessed of a certain fertility without being excessively fertile, and is suitable for orchid growth. The quality of bamboo root mud depends on three factors: first, the original soil quality, which is the predecessor and foundation of the bamboo root mud, sandy loam being the best; second, the number of years the bamboo clump has been planted - the longer the time, the more fully the effect of the bamboo roots, bamboo leaves and bamboo rhizomes; third, the distance from the bamboo stump - the closer the soil is to the bamboo stump, the better.

(3) Vetch bran soil.

Vetch bran is made by harvesting, sun-drying and crushing the plants of a green manure (Chinese milk vetch). Mix the vetch bran with bamboo root mud or ordinary sandy loam, pile it up and let it decompose, and it becomes vetch bran soil. The preparation method is: choose a rain-sheltered site, spread a layer of soil, scatter a layer of vetch bran, pour on a round of * manure water, and pile up layer by layer in this way; after the pile is finished, sprinkle water on the surface to moisten it, then coat it with thin mud to seal it. After piling and fermenting for half a year it can be used.

When using, mix it into other growing media in proportion.

(4) Leaf mould.

Made by piling up fallen leaves or green grass and tall stalks, watering or applying fertiliser, coating with thin mud to seal, then decomposing and sieving. It is best to use green grass that has not set seed, and to let it decompose fully, killing pests, diseases and weed seeds, otherwise there will be a great many weeds in the orchid pots later.

(5) Mountain soil.

That is, the forest soil in the mountain woods where wild orchids originally grow. It is leaf litter and fallen leaves accumulated and rotted over many years and mixed with the soil. The naturally formed leaf mould contains abundant humus, is loose and air-permeable, and is very suitable for orchid growth. Where transport is convenient, digging up mountain soil in large quantities to plant orchids is relatively simple and economical, and is even better for domesticating raw plants. The humus soil under broadleaf forests, especially the leaf mould under chestnut trees, is a very ideal soil for orchids.

(6) Pond mud.

In conjunction with winter repairs to ponds and fish ponds, dig the mud out, dry it in the sun, then break it into fine granules; it can be used to cultivate all flowers, including orchids.

(7) Field soil.

That is, choose loose topsoil from the fields, mix in a little sandy soil or a small amount of rice-husk ash, then add some decomposed compost or organic fertiliser such as fermented and decomposed bean cake or rapeseed cake, to improve the soil structure and enhance fertility. After turning and mixing evenly several times, sieve it. This kind of soil is near neutral and is not as good as humus soil. Therefore it is only used reluctantly when there is no suitable humus soil or mountain forest sandy loam, and is mostly used for cultivating coarse orchid varieties.

(8) Cow dung soil.

Break up and grind fine dried fermented cow dung, and mix it into sandy soil or the topsoil of field soil, prepared in a 1:3 ratio. It is best to select cow dung from cows fed dry fodder in winter, because after the dry fodder is ruminated in the cow's stomach, although the fibre is fine and broken, it is still full of elasticity, and being plant fibre it contains a certain amount of nutrients. This cow dung soil is loose and soft and rich in fertiliser, and is extremely suited to the orchid roots' love of air. In Taiwan, China's orchid-growing circles, people often use this cow dung soil as a filling material for cultivating terrestrial orchids, with very good results. Abroad, for cultivating terrestrial orchids, generally 5 parts humus soil or leaf mould plus 1 part sand is used; or 3 parts peat soil plus 1 part river sand, mixed with broken dried cow dung, thoroughly mixed and used. The cultivation substrate for epiphytic orchids is mainly moss and ferns, with a small amount of tree leaves, small pieces of charcoal and broken dried cow dung added. Before using soil to plant orchids, expose the soil to sunlight for disinfection and sterilisation. In summer, spread the soil out and let the sun expose it for more than 3 days, which can kill the pathogens and insect eggs within. Before use, the growing medium should be tested and its pH adjusted. For soil that is too acidic, lime can be used to adjust it. For soil that is too alkaline, use superphosphate, ferrous sulfate, etc. mixed into the soil. In short, it is best to keep the soil pH neutral to slightly acidic (i.e. pH 5.5-7). Using organic fertiliser, such as fertiliser composted from green grass and tree leaves, added to the soil to change the soil pH is a better method. In addition, before planting orchids, the nutrient soil should be sieved and graded, separating the large granules from the small ones.

When planting orchids, place the large granules at the bottom of the pot to facilitate drainage. At the same time, the degree of dryness and moisture of the soil should also be properly adjusted, neither too wet nor too dry. It is best to ball the soil in the hand and squeeze hard so that the soil forms a ball; open the hand and shake it a little, and the soil again breaks into granules - such a degree of dryness and moisture is suitable.

2. Preparation of the orchid-growing site 1. Productive ground planting The original environment of terrestrial orchids is growing among mountain forests and secluded valleys, on high, refreshing terrain, with trees for shade, forming a moist microclimate. The temperature difference is small and the air is clean.

When introducing and domesticating them, one should first simulate their wild environment before they can be grown with abundant flowers and lush leaves. At present, with industrial development and urban modernisation, and greening work unable to keep up accordingly for the time being, they suffer pollution from factories and vehicles. Therefore orchids cultivated in the city do not grow as robustly as those in the suburbs. There is a gap from the original environment of wild orchids, and a great difference from the meteorological factors of the original habitats of Cymbidium kanran and Cymbidium ensifolium, so in the domestication and orchid-planting site careful design was made and practical arrangements were made for regulating environmental factors.

The orchid nursery occupies about 1.5 sq m [sic, ten thousand sq m as written: 1.5 wan sq m], is rectangular, and has a rectangular pond for storing rainwater. In the nursery, every 2.5 m or so a 2.5 m high moso bamboo pole is fixed, and above, moso bamboo is tied horizontally into a frame, used to lay and tie the first layer of shade netting; 20 cm below the first layer of shade netting, another horizontal thin moso bamboo is placed, used to lay out the second layer of movable shade netting. The first layer of shade netting is basically fixed from spring to autumn, and the second layer can be opened or closed as needed. Light and temperature are carefully regulated. The seedbed width is 1.2 m, the length 12-16 m (depending on the terrain), the height about 30-40 cm (5-7 bricks high), the seedbed spacing 50 cm, and the passage width 130 cm. This facilitates daily management. In winter, every two beds are tied with a plastic greenhouse for warmth. On snowy days, pay attention to clearing the snow and avoid too much snow crushing and collapsing the plastic greenhouse. About every mu (one mu is about 667 sq m) of land, two water tanks with a storage capacity of 1 cubic metre are built with masonry, to treat tap water. In winter, 100-150 watt bulbs are set up about 4 m apart inside the plastic greenhouse, mainly for raising the temperature.

2. Open-field cultivation

(1) Growing orchids in the ground in tree shade.

This is for ornamental purposes, making use of sparse tree shade in front of houses, in wall corners or in scenic areas, planted appropriately in the ground, but the original barren clay must be dug out and replaced with loose humus soil or good field topsoil.

When winter arrives, spread some straw over the mud surface at the roots to avoid freezing injury to the orchid roots. If there is severe cold, straw curtains or other soft coverings must also be laid over the leaf clusters to prevent cold damage. Apart from needing strengthened management and protection in the intense heat of midsummer, this kind of ground-planted orchid cultivation can generally be extensive and left to grow naturally. Orchids planted in the open field are all coarse varieties without petal types. The following spring, after the weather turns warm, the cold-protection coverings can be removed. After growing for many years, as long as they are watered and fertilised in good time, their adaptability is relatively strong, and they can bloom abundantly year after year, with delicate fragrance drifting far - a fine item for embellishing the countryside.

However, when arranging ground-planted orchid cultivation, besides considering the tranquillity of the layout

(2) Pot cultivation of orchids.

This refers to growing orchids under a shade frame.

For pot cultivation of orchids, it is best to use clay pots, that is, unglazed fired tile pots; they have good air permeability, can filter water, and are cheap. They are economical and practical orchid-growing utensils. But tile pots are rather rough and not attractive, and are unsuitable for exhibitions. Porcelain pots or glazed pots are attractive in appearance, but their air permeability and water filtration are both very poor; if used for long-term orchid growing, they easily rot the orchid roots and make it difficult for orchids to grow vigorously. Therefore, when using porcelain or glazed pots for orchids, one must place more drainage tiles at the bottom of the pot, or fillers such as clam shells; and watering must be restrained and not excessive. If orchids are grown in clay tile pots, they can be slipped into larger porcelain or glazed pots when participating in exhibitions. Yixing purple clay pots are attractive and elegant in appearance and also have a certain air permeability, and are relatively suitable for growing orchids. Newly bought orchid pots must be soaked in water for several days; especially tile pots just out of the kiln must be allowed to absorb enough water, completely eliminating their fiery dryness. For general orchid growing, newly planted orchids mostly use new pots, and repotting mostly uses old pots. For any potted orchid, it is best not to sit it directly on the ground, because it is easily disturbed by insect pests and overgrown weeds. Especially in hot summer, with the scorching sun, the ground temperature rises and harms the orchid plants; whenever there are thunderstorms or in the plum rain season, the humid heat rises even more, easily steaming the orchid roots; moreover, being close to the ground, ventilation is poor. This is detrimental to aerial root growth. To reduce the above effects, the orchid pots can be placed on an orchid stand built of cement slabs, facilitating upward and downward convection and constantly supplying fresh air, promoting orchid respiration, enhancing metabolic function, accumulating nutrients and energy production, so that orchids grow robustly, and also avoiding harm to the orchid roots from ants, slugs, etc. If conditions are restricted, an empty clay pot can be turned upside down on the ground, and the potted orchid placed on top of it.

3. Orchid room cultivation The orchid room is mainly for the overwintering of terrestrial orchids.

Different kinds of orchids have different ecological habits, so the time for bringing them indoors for the winter and the room temperature requirements also differ. For terrestrial orchids, as long as the temperature is not lower than 7°C-8°C, most can be cultivated in the open air. In Jiangsu and Zhejiang, the custom is that after the Beginning of Winter, Cymbidium ensifolium, Cymbidium kanran and Cymbidium sinense, which require a slightly higher temperature, are moved indoors for cultivation, and some Cymbidium goeringii and Cymbidium faberi with flower buds are moved under the eaves or to cold-sheltered places, so as not to be attacked by the first frost and affect flower bud development. After Lesser Snow, potted orchids raised from pseudobulbs and thin, weak small plants, especially orchids of the plain-heart petal type, are gradually moved indoors and placed on orchid stands near the window so as to receive sunlight. After Greater Snow, all potted orchids are moved indoors for care. Before orchids enter the orchid room, first wash the area around the orchid pots clean, which both prevents mud and dirt from contaminating insect eggs, mould, etc., and makes things look clean and elegant. When placing orchid pots, pay attention to reasonable arrangement, both to facilitate sunlight penetration and to favour ventilation. When terrestrial orchids overwinter indoors, the key is to manage temperature and humidity well. Generally the room temperature should be kept above 7°C-8°C, and for Cymbidium sinense the ideal is 10°C-15°C. After the orchid pots are brought indoors, if the weather is not yet severely cold and freezing, the south-facing window should be opened around midday and a small vent opened on the north side, to facilitate indoor air circulation. In the evening, if the indoor temperature is still above 5°C, the small vents on the south and north sides can be opened slightly; if below 5°C, all windows should be closed. In the depths of winter, only on windless, clear days at midday should the windows be half-opened slightly for a little ventilation; once the sun leans a little, close the doors and windows, and towards evening hang straw curtains or cotton cloth curtains. If the temperature continuously drops below 3°C-5°C, a coal stove with a chimney pipe can be used for heating. After the Beginning of Spring, the climate gradually warms; at clear midday the doors and windows of the orchid room can all be opened wide, but attention must be paid to changes in temperature; in the afternoon, as the temperature gradually drops, it is best to leave the south window half-open and half-closed; before nightfall, close everything properly again.

During this period, the temperature of the orchid room is best kept at around 10°C; if the temperature is on the high side, it will cause the early-flowering varieties of Cymbidium goeringii to bloom early, and the flowers are also liable to wilt early. In early spring, one must especially guard against a late spring cold snap, which affects the growth of the flower buds and may even freeze the orchid roots.

After Awakening of Insects, all Cymbidium goeringii and Cymbidium faberi without flower buds can be brought out of the room and placed on open-air stands, with reed curtains added over the frames at night to guard against frost damage. All kinds of orchids with flower buds should still be kept in the orchid room for care, and only after Qingming can they be moved outside for cultivation; but at night attention must still be paid to guarding against late frost. During the period of indoor orchid cultivation, especially in the severely cold season, special attention must be paid to the dryness and moisture of potted orchids. The potting soil should be dry; when watering is needed can be judged by looking at the pot surface: if the surface layer of soil is in a powdery, loose state while the soil below is still slightly moist, do not wait until the potting soil is completely dry before watering. When watering, first move the potted orchid down and place it on the ground, water along the water channel at the pot rim, and on no account let water soak into the leaf clusters. The orchid pot can also be placed in a water vat to soak shallowly for a few minutes, with the water limited to reaching the waist of the pot. When watering, if water soaks into the leaf sheaths, it should promptly be wiped off with a dry cloth, or allowed to dry in the sun before the pot is moved back indoors. Because orchids are kept indoors for a long time, much dust often adheres to the leaf surfaces, hindering metabolism. One can choose clear, warm weather, and around midday move the pots outside into the sunlight, and use a fine-holed watering can to spray and clean the leaf surfaces, washing away the dust and grime; after the water marks dry, move them back indoors. If the water marks are not dry, the moistened parts of the orchid leaves are liable to turn black and wither. When growing orchids indoors, during the heating period, the indoor air temperature is often on the high side, the leaf clusters appear dry, the soil surface in the pot is dry and loose, or the moss on the pot surface is withered. Then water should promptly be sprayed on the passages and walls, letting it evaporate, to regulate the temperature. In short, for indoor orchid cultivation, whether the orchid plants in the pot or the moss on the pot surface, it is best to keep them green and fresh. If one is an amateur orchid grower, limited by conditions, one can make use of a spot outdoors facing south and towards the sun along a wall: one side leans against the wall body, and the other three sides are built with bricks into a single-slope ground box. The size can be determined by the number of pots. On the slope of the ground box, install a wooden-framed glass window or plastic film window that can be opened and closed. For those with long, tall orchid leaves, place them in the higher space near the wall, on inverted empty flower pots, or on stacked bricks, wooden strips or cement slabs at suitable heights. Short orchid pots are arranged in rows towards the front, and all leaf tips or the tops of the ring leaves must not touch the glass or plastic film of the window surface. In the severely cold season, whenever the temperature is too low or on windy and snowy days, the sloped window must be covered with enough straw curtains or other coverings to prevent cold air from entering. When the weather is clear and mild, especially after the Beginning of Spring, when the sun shines, the cold-protection straw curtains can be removed; at midday when the sunlight is fairly strong and the temperature slightly higher, the window cover can be lifted and propped open a crack to regulate fresh air. After the sunlight slants, the window cover should immediately be closed. In daily care, great attention must be paid: too many water droplets must not condense on the glass of the window cover, to prevent them from dripping into the leaf clusters, where the moistened parts often turn black and rot or even die.

3. Planting orchids 1. Planting timing Whether repotting or newly planting, the choice of timing has a great influence on the survival, growth vigour and development of orchids. It is therefore very important. Generally the more suitable time is the orchid's dormancy period, that is, March to April, before the new shoots have emerged from the soil; in terms of the solar terms, it is between the Spring Equinox and Qingming. If done after the new shoots have emerged, the operation is very inconvenient, and a little carelessness will break or injure the new shoots. When the orchid's dormancy period is about to end, and the new shoots and new roots are just about to grow but have not yet grown, planting at this time is best; shortly after planting they can send out roots and shoots and resume normal growth. If planting is too early, then after planting the orchid is not easily revived, and in case of low temperature, cold wave, late frost or spring thunder, freezing injury is often caused. In the Yangtze River basin, orchid rooms are seldom heated in winter. Winter is very cold, so dividing is not advocated in the severe cold of winter. To make the operation convenient when dividing, the soil can be allowed to dry appropriately before division. This makes the roots turn white and produce an inconspicuous shrinkage, making the originally brittle and easily broken fleshy roots soft and pliable, so that when dividing and potting the roots are not broken too much. For larger orchid nurseries, the planting workload is great and takes a long time from start to finish. Precious varieties should be arranged for planting at the best time. Ordinary varieties can be postponed or advanced as appropriate.

2. Using orchid seedlings For propagation, orchid seedlings that grow well and are free of pests and diseases should be selected.

After 2-3 years of cultivation, orchids need a change of soil or pot, and at this time division propagation should be combined with it. When repotting, support the bottom of the flower pot with the palm of the left hand, carefully extend the fingers of the right hand into the orchid seedling's leaf cluster to block the potting soil, then lay the orchid pot on its side, with the pot body tilted sideways facing the person, and the lower edge of the pot mouth touching the ground. At this point, lift the pot slightly upward with both hands, gently tap the lower edge of the pot against the ground, let the potting soil loosen, rotate the pot body and change the contact point of the lower edge of the pot mouth against the ground, so that the potting soil gradually loosens evenly and separates from the flower pot. Support the orchid plant with the right hand and remove the flower pot with the left hand. If the orchid plant is too tall, it is better to tap the lower edge of the pot mouth against the edge of a wooden chair or cement platform, so that the orchid leaves hang in the air and are not injured or broken. After the orchid potting soil has separated from the pot, lay the orchid seedling and potting soil flat, so that the soil ball does not suddenly loosen and crack open, causing the orchid root system to break. Then carefully pat the soil ball gently to loosen it, and gradually shake off the old potting soil. Carefully grasp the pseudobulbs so as not to injure the leaves and tender shoots, and especially protect the root tips. Cut off the leaves that have already turned yellow and withered, the rotting sheath leaves on the pseudobulbs, and the rotted, hollow, dried old roots. However, for pseudobulbs with new shoots, the leaves should be retained as far as possible to promote good growth of the new shoots. For the larger clumps that have been selected and cleaned up, find the natural gap where two pseudobulbs are relatively far apart and easily loosened when shaken by hand, cut the two pseudobulbs apart (what earlier people called "opening the road"), then hold the bases of the two clumps with both hands, and along the road shake gently and pull slowly to divide them into two clumps. Trim the separated orchid clumps appropriately, then soak them in a 800 times water-diluted thiophanate solution for 10-15 minutes; only the roots should be soaked, not the leaves; a 1000 times potassium permanganate solution can also be used for disinfection. Note that only the wounded parts are disinfected, then dry the orchids in a cool, ventilated place. When the orchid roots have become soft and easily bent, they can be planted. Generally, in clear weather, drying for half a day is enough; of course they must not be dried too much.

3. Planting procedure For the separated orchid clumps, do not split them too sparsely; each clump should have at least 3-5 seedlings, and it is best to keep one-year-old plants, two-year-old plants and three-year-old plants in the same clump.

(1) Padding the pot.

Cover the drainage hole at the bottom of the pot with a piece of tile, then gradually fill with bricks, tiles or shells, filling the large gaps with mud granules or bean-sized stones, generally to about 1/2-1/3 of the pot's internal height. The remaining clear height is about 10-15 cm, reserved for the growing medium layer. Its specific height should be determined according to the orchid species, the length of the orchid roots and the height of the pot. The padding should not be filled too densely or too solidly; a little porosity should be retained. Practice has proved that some new roots can grow well in the pores of the padding layer.

(2) Planting.

On the padding layer, first fill in 2-3 cm of growing medium, press it slightly firm with the hand, then place the orchid upright on it. According to the size of the plant and the flower pot, several single plants, 2 clumps, 3 clumps or more clumps can be planted in one pot. 3 clumps are suitably planted in a tripod arrangement. 4 clumps can be planted in a square. 5 clumps are suitably arranged in a plum-blossom shape. The orchid roots should spread out naturally and the leaves should spread in all directions. Slowly place the orchid roots into the pot so that the orchid roots spread naturally and as far as possible do not rub against the inner wall of the pot. After the orchid plant is in the pot, gradually fix the posture of the orchid plant. For one clump per pot, the old pseudobulbs should be placed to one side, leaving room for the new shoots to develop. For multiple clumps per pot, the old pseudobulbs of each clump should be gathered relatively towards the middle of the pot, so that the new roots and new shoots developing outwards each have enough space.

(3) Filling soil.

When planting, hold the leaves with one hand and add nutrient soil with the other, holding the base of the orchid plant and lifting it slightly upward to spread out the root system, while shaking the orchid pot. Let the growing medium penetrate deep into the root zone; continue adding soil and shaking the orchid pot to adjust the position and height of the orchid plant. Press with the hand along the pot edge, but do not press too hard lest the roots be injured; continue adding soil and pressing until the soil surface is 2-3 cm above the pot mouth, slightly in a steamed-bun shape. The growing medium should cover all the orchid roots, burying up to the base of the pseudobulbs. As for the depth of soil filling, tradition holds that Cymbidium goeringii should be shallow and Cymbidium faberi deep, but generally the measure is not to bury the leaf bases on the pseudobulbs. When newly collected orchids grow in the wild, the plants retain clear markers above and below the soil surface, and these markers can be taken as the standard. The size of the flower pot should also match the size and number of the plants; there should be neither a large pot with small and few plants, nor a small pot with large and many plants. Generally, the number of plants should be such that they are expected to just fill the pot after 2-3 years. The size of the plant should match the height of the pot. This is both conducive to growth and meets ornamental requirements.

(4) Top dressing.

After planting is complete, a layer of small stone granules or green moss can be spread on the surface of the potting soil, preferably high-quality moss from under the forest; it is both attractive and can regulate moisture, and can also protect the leaf surface from being polluted by muddy water, and the new shoots will not rot at the heart from being infected by pathogens in the soil; in addition, it can also slow the washing away of the potting soil by rain and keep the potting soil loose.

(5) Watering.

After planting is complete, water the first time immediately; the potting soil must be thoroughly wetted, and the water droplets should be fine and the force not too great. If placed in a water basin to soak up water, on no account soak too long. As soon as the potting soil is soaked, immediately take the orchid pot out, then move it to a shaded place for care.

4. Care and management after planting Mastering the art of planting orchids is of course very important, but managing and caring for orchids well is even more difficult, hence the saying "three parts planting, seven parts care". The care of orchids requires understanding the environment, accumulating care experience, and patience and attentiveness. The most important thing is to master the patterns of orchid growth and development: when they sprout, when they grow leaves, when they flower and when they go dormant. Then carry out care and management in terms of temperature, humidity, watering, fertilising, ventilation, plant protection, cherishing the leaves and protecting the flowers, and one will certainly grow orchids well.

1. Cherishing the leaves Orchid leaves are soft and graceful yet not weak, upright and firm yet not stiff.

Orchids are moving and lovely, but good flowers do not come often, and when the flowers fall there is nothing to be done; yet orchid leaves stay green through all four seasons, forever full of vitality, giving people enjoyment that lasts all year round. The elegance of the orchid is both revealed in the flowers and entrusted to the leaves.

And lush leaves are the prerequisite for good flowers; when leaves are healthy and lush, the plant produces abundant nutrients on its own, resulting in many beautiful flowers. If the leaves are sparse yet the flowers are numerous, it is merely a sign of rapid decline. The key to cherishing the leaves is first of all to control the degree of shading, air humidity, appropriate water and fertilizer, and maintain good ventilation. This keeps orchid leaves lush and healthy, verdant and glossy. It is also necessary to strengthen pest and disease control, and prevent damage from wind, rain and mechanical injury. In addition, the leaf tips must be preserved; the tips of orchid leaves are like the tip of a sword, the point of a brush, or the tip of an eyebrow, able to convey expression and spirit. Losing the leaf tip makes the plant look abrupt and dull. The key to preserving leaf tips lies in ensuring the water and nutrients the orchid needs are sufficient, the potting soil is loose and breathable, so the root system is well developed and intact, the plant grows vigorously, and no scorched tips occur. Some people believe that the mark of an orchid kept well is that the leaf tip can pass through the eye of a needle, which means the leaf tip is intact and its sharp point undamaged. The shape of leaf tips differs among orchid species: some are acuminate, some obtuse and rounded, some notched, some upturned. As for leaf color, some orchid varieties have golden or silver tips (that is, the leaf tips are yellow or white) and appear precious and rare; this is another layer of charm of leaf tips in leaf appreciation. During care, attention should be paid to protecting orchid leaves at ordinary times; when handling, be gentle and careful, do not bump the orchid leaves, and maintain their natural posture.

Contaminated leaves should be carefully cleaned; sprayed water must not accumulate in the center of the leaf cluster. Dead yellow old leaves and diseased leaves should be cut off promptly. For partial pruning of orchid leaves, a slanted cut can be made at an appropriate spot, and the resulting pointed angle should be less than 30. Some also cut twice, but it must not be cut into a flat head.

2. Flower protection After the flower buds emerge, if there are too many, they consume excessive nutrients from the mother plant, hindering the formation and vigorous growth of leaf buds, so excess thin and small flower buds should be removed early; keep one flower bud z per orchid seedling.

Each pot should preferably retain 3-5 flower buds. Retain flower buds appropriately according to the orchid variety, the size of the pot, and the number of seedlings. To protect and develop rare varieties, all flower buds can also be pinched off to let them proliferate luxuriantly. During the period from flower bud elongation to flowering, moderate light should be maintained so the flower color is bright and full, rich in luster and full of fragrance. If the light is too weak, the flower color will be pale and lacking in luster. Flowers that remain open too long consume nutrients and hinder bud emergence, leaf growth, and flowering the following year. The flowers of Cymbidium goeringii (spring orchid) bloom for about half a month; after they fade, the flower scape should be cut off promptly. For Cymbidium faberi (Huilan), when the last flower of the inflorescence has been open for 1 week, the inflorescence should be cut off. When pinching off the flower scape, steady the leaf base with one hand and press the flower scape to one side with the other, then it can be broken off from the base and pulled out, or it can be cut off. The removed flower scape can be placed in a vase and enjoyed for many days. Generally, orchids are not allowed to be pollinated and set seed after flowering, especially those that are not very robust and rare varieties; otherwise it affects flowering the following year. If hybrid breeding is to be carried out, artificial pollination should be done at the appropriate time. The mother plant should then be carefully managed so its seeds are plump and mature.

3. Temperature Most of our country lies in the temperate and subtropical zones, while orchids generally come from places with mild and humid climates, relatively high annual average temperatures, and long frost-free periods. In northeast and northwest China, orchids are rarely grown, mainly because of temperature constraints. The northernmost distributed Cymbidium species in our country are Cymbidium goeringii and Cymbidium faberi. Along their distribution line, there is frost or short-term snow in winter, and summer temperatures are relatively high. However, because orchids mostly grow in mixed broadleaf and coniferous forests or in bamboo groves, the trees both block the summer sun and resist the winter cold wind; even in places covered with snow, the impact on orchids is not great, because snow actually protects orchids through winter, and the ground temperature beneath the snow is generally not lower than 0°C. In our introduction and domestication of Cymbidium ensifolium and Cymbidium kanran, we have already pushed them 600-1000 km northward from their places of origin, and on a large scale in ground planting. It can be seen that the survival ability and adaptability of orchids are still relatively strong. In most areas of northeast, northwest and north China, winters are too cold, and outdoor orchid cultivation is unsuitable. From mid-to-late October to late April of the following year, about half a year, orchids all need to be moved indoors or into greenhouses for cultivation. In the lower Yangtze region, orchids also need to be brought indoors in winter or heated in sheds. In Fujian, Guangdong, Guangxi, Yunnan, Sichuan, Taiwan, China and other provinces and regions, Cymbidium kanran and Cymbidium ensifolium generally do not need to overwinter indoors in winter. In Jiangxi, Hunan and parts of Sichuan, certain measures are still needed in winter to protect orchids.

Orchid temperature requirements: The temperature for orchid seed germination is: 21°C-25°C during the day, 15°C-18°C at night. The temperature required for grown terrestrial orchids is 20°C-22°C during the day and 13°C-0°C at night.

During the winter dormancy period of orchids, the temperature can be lowered. For example, Cymbidium goeringii and Cymbidium faberi require a minimum nighttime temperature of 4°C-6°C in winter, and dropping to 0°C is also acceptable; under dry conditions, it does not matter if the plant leaves drop to minus 2°C-3°C. Orchid flowers develop from flower buds, and flower bud differentiation is closely related to temperature and light. Predecessors did much research on orchid flower bud differentiation and concluded that a low temperature of 12°C-13°C is sufficient for flower bud differentiation, and the relationship with day length is not very great. But the more light the orchid receives, the more pronounced the effect of low temperature on flower bud formation. Therefore, from late spring to autumn, placing orchids outdoors for cultivation is better for growth and development than indoors. The purpose of regulating temperature mainly has 3 aspects, namely: preventing cold in winter, preventing summer heat, and changing the flowering period. When the winter temperature is below 0°C, orchid leaves and flower buds are prone to freezing injury, with water-soaked black spots appearing on the leaves and flower buds wilting. If the temperature drops suddenly and sharply or there is a severe frost, the damage is even greater. But winter temperatures being too high is also not good, because orchids are in a dormant state in winter, and too high a temperature interferes with dormancy. In summer, if the temperature is too high and orchids suffer from heat, the leaves turn yellow, become rough and lusterless, and are susceptible to disease invasion, often with decay beginning at the leaf base. The flowering period of orchids is very obviously affected by temperature; under general conditions, appropriately raising the temperature can make them bloom earlier. For example, under cultivation conditions in plains and cities, the flowering period of orchids is often 15-30 days earlier than under original wild conditions. Using this biological characteristic, the temperature can be appropriately regulated to advance the flowering period by half a month to one month. This is especially true for species that bloom in spring; generally, flower buds have already formed by July-September of the previous year, and after they pass through the winter dormancy stage, appropriately raising the temperature can make them bloom early, in time for the Spring Festival holiday. But it must be pointed out that raising the temperature must be done step by step. Experiments show that rapid temperature increase instead produces an inhibitory effect and delays the flowering period.

Methods of regulating temperature:

Temperature has an enormous influence on orchid growth and development. If the temperature is too high, respiration speeds up and nutrient consumption increases; if too low, enzyme activity decreases, synthesis is reduced, and growth and development slow down. What is important is that a daily temperature difference and a seasonal temperature difference must form, so that sprouting and flowering can occur. In temperature regulation for domestication and cultivation, we adopt the principle of approximating the original orchid producing areas. In summer, double-layer shade nets are used to shade the orchid nursery, and the cooling effect is obvious: when the air temperature reaches as high as 35°C, the temperature in the orchid nursery is only 31°C-32°C. In winter, plastic greenhouses are used to keep warm; when the air temperature is as low as 0°C, the inside of the plastic shed can still remain at 6°C-8°C, and the winter temperature difference is smaller than in the open field, which is beneficial for nutrient storage and also prevents freezing injury. Besides building soil orchid sheds and orchid rooms, temperature can also be regulated by planting trees, shrubs, vines and lawns around the orchid nursery. In summer they can absorb part of the solar radiant heat, and in winter they can slow the loss of heat from the ground and air. Taking lawn as an example, according to measurements, in winter the air temperature over grassland is higher than over bare ground, with a maximum daytime difference of up to 4.4°C, helping to avoid freezing injury; while in summer the air temperature over grassland is much lower than over concrete ground, helping to prevent heat and cool down. In summer, it is advisable to spray or sprinkle clear water in the air, on the ground surface, on the flower benches and on orchid leaves. Because water absorbs part of the heat when evaporating, it can play a role in cooling and preventing heat; similarly, expanding the water surface nearby also has this effect, such as ponds, reservoirs, ditches, and water vats. Greenhouses need curtains hung on the glass to block light and prevent heat. In hot weather, even more attention should be paid to ventilation and strengthening air convection for heat dissipation, partially lifting the covering on the shed; in orchid rooms, open doors and windows to avoid accumulation of hot air. In regulating temperature, besides air temperature, soil temperature should also be noted. Orchid roots grow in the soil, and the temperature of the potting soil has a direct influence on their physiological functions. Under general conditions, soil temperature and air temperature are positively correlated; when air temperature is high, potting soil temperature also rises, but the change process is relatively slow. First, prevent direct sunlight from heating the flower pot and scorching the soil and pot, burning orchid roots close to the pot wall; also note that when watering, the water temperature should be close to the soil temperature and not too different. There is also a question worth exploring, namely the relationship between artificial protection and the orchid's own adaptability. Like all plants, orchids have their own adaptability to the external environment. They are not inherently delicate. Therefore, when orchid growers protect orchids from heat and cold, their measures should be moderate. Covering too densely and for too long will inevitably weaken their resistance. In our orchid nursery, the Cymbidium kanran and Cymbidium ensifolium introduced and domesticated from 600-1000 km away in the south, besides protective measures, are also gradually allowed to strengthen their resistance and gradually adapt to the new environment.

4. Humidity Humidity generally refers to relative humidity, commonly expressed as a percentage.

Orchids have no fibrous roots, still less root hairs, so their water-absorbing surface is small; on the contrary, orchid leaves grow in clusters. Leaf transpiration is relatively large, and only when the air is humid can the balance between water absorption and transpiration be maintained. In the growing season at the places where orchids originate, rainfall is abundant and the air is humid, with relative humidity above 80%; especially Cymbidium sinense, which grows beside streams where water mist is often diffused, has relative humidity around 90%. One important reason why growing orchids in the north is difficult is dry air. Generally, growing orchids in urban homes and on balconies is not easy to succeed at, and insufficient temperature is also a main factor. When air humidity is low, orchid leaves are rough and dull without luster; when air humidity is suitable, the leaf surface is moist and green. Usually the humidity required during the orchid growing season cannot be lower than 70%, and in the winter dormancy period it is about 50%; at night air humidity should be somewhat higher than during the day. Humidity and ventilation are two relatively contradictory factors; too much ventilation lowers humidity. In winter and spring in the north, dry winds blow frequently and humidity cannot be maintained, which is unfavorable for orchid growth, so ventilation should be appropriately reduced.

Methods of regulating and increasing air humidity:

Plant many trees, bamboo and grass around the orchid nursery. The root systems of these plants can absorb large amounts of water from underground and then release it through transpiration from the leaves above ground. They can also retain surface water and release it gradually through transpiration, increasing the content of water molecules in the air and thereby raising air humidity. When the ground is dry, sprinkle water on the ground, benches and walls, which also has the effect of lowering temperature. Water can also be sprayed or sprinkled in the space of the orchid growing site or on the leaf surface. However, sprinkling or spraying water on the leaf surface should not be done at night; if the leaf surface needs to be sprinkled in the evening, it must be ensured that the leaf surface can return to dryness by night. In southern China there are sometimes continuous rainy days, especially in the plum rain season when humidity is too high, so doors, windows and coverings should be opened for ventilation. Orchids like warmth and moisture; when humidity is high and ventilation is good, orchids grow robustly; but when the temperature is low and there is no ventilation, water vapor condenses into droplets, which is harmful to new shoots and easily causes disease, so low temperature and high humidity should be avoided. In our large-area ground-planted orchid seedling beds, bricks are laid around, and moss is planted on top. Bricks and moss have very strong water-absorbing and moisture-retaining capacity; this economical and convenient natural humidifying measure is very effective.

5. Watering When watering, attention should be paid to water quantity, water quality, water temperature, watering time, watering method and other issues.

In the classification of xerophytes, hydrophytes and mesophytes, orchids belong to mesophytes and do not need too much water, so the potting soil should not be too wet. This is determined by the structural characteristics of orchid roots and stems. The pseudobulbs of orchids are fat, with a cuticle on the surface, and the epidermal cells are thickened to form stone cells; the stem is filled with vascular bundles. The pseudobulbs can store nutrients and water and are not easy to evaporate. Orchid roots are mostly fleshy, with the outermost layer being velamen tissue, whose cells are elongated cylindrical or polygonal. When the velamen tissue cells mature, the protoplasm disintegrates and thickened striations form on the cell walls. The function of the velamen tissue is to protect the cortex, absorb water, and reduce and protect against the loss of water inside the cortex. Therefore, orchids should not be watered too frequently, and the potting soil should not be too wet, so as to avoid root rot. In addition, judging from the places where orchids originate, orchids mostly grow on hillsides, on both sides of ridges, and in rock crevices. These places drain well and have no trouble with accumulated moisture or waterlogging. It is precisely in adaptation to such an environment that orchid root and stem structures are suited to storing and retaining water and nutrients.

Principles of watering orchids:

The following conditions must be relied upon:

(1) The type of orchid.

Epiphytic orchids and those with aerial roots can be watered less. For example, Cymbidium hookerianum has aerial roots and can absorb water from the air, so it need not be watered too much. In addition, those with thick cuticles on the leaves should be watered less; for example, the leaves of 'Tiegusu' have a thick cuticle and low water evaporation, so watering must be strictly controlled.

(2) The growing season of the orchid.

In spring, when the temperature gradually rises and it is the season for new buds to sprout, watering should be timely. Water once a day or every other day to keep the potting soil moist. During this period, lack of water causes delayed flowering and weak buds. In summer, when the temperature is high and water evaporation is large, and it is the period of leaf expansion, root emergence, and root and leaf elongation, water once every early morning; in the evening, if the potting soil is dry, some water can be added to moisten the potting soil, moisten the leaves, lower the temperature, and reduce nutrient consumption, so as to facilitate growth and development. Entering autumn, the temperature gradually drops and orchid growth slows; observe the dryness or wetness of the potting soil every day, water when dry, and leave it when wet. In winter, orchids enter dormancy. The potting soil should be slightly dry, and watering should be reduced or omitted, but attention should be paid to the potting soil to prevent it from losing too much water and instead drawing water out of the roots. At the turn of winter and spring, after Cymbidium goeringii buds and flower buds begin to elongate, the potting soil should also maintain a certain humidity. If the potting soil is too wet in winter, the water content of the orchid plant increases, which easily causes freezing injury.

(3) The growth condition of the orchid.

If the orchid grows strongly and the roots are good, water more; otherwise reduce as appropriate, and for diseased plants water must be controlled even more. When orchids are sprouting and growing, water can be somewhat more; after sprouting, it can gradually be reduced. When new shoots gradually mature, water should again be somewhat less; when flower buds appear, slightly more water; but during flowering, water should not be too much, so as to prolong the flowering period. After the flowers fade, watering should be stopped for several days to let the potting soil become slightly dry and the orchid rest a little, and then water again.

(4) The condition of the flower pot and the plant.

That is, water according to the texture and size of the flower pot: water more for clay pots and large pots, and less for porcelain pots and glazed pots. Water more when there are many potted plants or when ground-planted orchids are densely planted.

(5) The dryness or wetness of the potting soil.

The bases for watering, such as season, plant, weather, flower pot and soil quality, can all be comprehensively reflected by the degree of dryness or wetness of the potting soil, so the dryness or wetness of the potting soil is the direct and intuitive basis for watering.

It can be judged by observation and touch. If the potting soil becomes hard, the color becomes lighter, and the moss on the pot surface is dry and wilting, it indicates that the soil is dry. It should be watered immediately. If the potting soil is dark in color, has moisture, and the moss is moldy, it is a sign that the soil is too wet and should not be watered. Generally, a soil moisture content of 15%-20% is suitable.

(6) Watering time.

Generally speaking, in spring and autumn it is suitable to water in the morning; during the hot midsummer period, it is suitable around sunrise and sunset; in early winter and early spring, water after the sun is at its zenith and the temperature has warmed slightly. During the period when they are brought indoors to overwinter, watering must be done at noon on clear days. But care should be taken to avoid wetting the leaf surface or soaking into the leaf sheaths. Among the people there are some very valuable experiences in watering orchids. For example, for Cymbidium goeringii and Cymbidium faberi there is the experience of "not dry in autumn, not wet in winter" and "pleased by moisture in spring, pleased by slight dampness in summer and autumn, and needing moisture with dryness in winter." This shows that orchids have different water requirements at each growth and development stage, and management should be adapted to local conditions and flexibly handled. Generally, after the Beginning of Spring, the climate gradually warms, the flower cores swell, and the soil should be kept moist, spraying water once every 2-5 days. After Awakening of Insects, for flowerless Cymbidium goeringii and Cymbidium faberi grown in the open, where wind and sun easily dry the pot water, daily watering should be frequent, but the amount should not be too much; water once every 2-3 days or a small amount once a day. After the Beginning of Summer, for all orchids that have finished flowering (including Cymbidium kanran and Cymbidium sinense), the soil should be somewhat drier, because after flowering most have a short dormancy period, grow slowly, and evaporate less from the leaf surface. From June onward, the weather gradually becomes hot, and the growth rate of daughter plants (that is, young shoots) speeds up. At this time, pay more attention to soil humidity and frequently spray clear water on orchid leaves and orchid benches to create a moist microclimate, which is beneficial for daughter plants to extend and put out leaves. During the plum rain season, watering should be controlled to reduce disease occurrence; leaf-variegated plants and some petal-type seedlings are even more prone to disease and should be watched even more. In the dog days, when the climate is hot, besides strengthening shading, carefully maintain soil moisture and spray clear water on leaves and the pot surface around sunrise every day. After White Dew, it gradually turns cooler in autumn, and with the nourishment of night dew, the growth of new grass pauses and orchid buds break through the soil and grow slowly; at this time, irrigation can be reduced; but when the potting soil is found to be dry, it must be watered until moist. In late autumn, new grass has turned from new green and tender green to deeper and darker shades. Flower cores and outer sheaths are all visible; guard against prolonged rain and excessive moisture to reduce rotten sheaths (that is, rotting of the bract sheaths), and measures should be taken to avoid rain and receive more sunlight.

(7) Water quality and water temperature for watering.

For watering orchids, it is best to use stored rainwater, which is the cleanest and also neutral; river water is next; well water contains minerals and is mostly alkaline, so it is relatively poor; tap water contains disinfectants and is the least suitable for orchids. If tap water must be used, it should be stored in a pond for more than 24 hours, and it is even better if exposed to sunlight, so that after the disinfectant settles or decomposes, the clearer water on top can be taken to water orchids. Besides this storage treatment, there is also an activation treatment, which is to keep fish, algae, Chlorella, red floating algae and other aquatic organisms in the pond where tap water is stored, in order to improve water quality. But attention should be paid to whether the fish have diseases, to prevent water quality contamination. The temperature of the potting soil can directly affect the water-absorbing function of orchid roots. Therefore, the temperature of the irrigation water should be very close to the potting soil temperature and air temperature. In hot summer, after flower pots and soil are heated by direct sunlight, if cold water is suddenly poured on them, the temperature difference is too great and will disrupt the normal absorption function of the root system and affect physiological balance. Therefore, in summer, orchids should be watered in the early morning and evening, when the water temperature is close to the soil temperature. Reservoirs or water vats are best half buried in the soil, with shading added, so that in summer the water temperature will not become too high.

(8) Watering methods.

Common orchid watering methods include watering, spraying and soaking. Usually a watering can, ladle or hose is used to water; when watering, pour slowly from the edge of the pot so that water gradually seeps downward and toward the center. Never pour suddenly into the center of the leaf cluster, and do not let water splash up the potting soil and dirty the leaves. Spraying should soak through the whole pot and must not be half-way watering, that is, with water only on the surface while the lower layer gets none. If half-way watering continues for a long time, the surface is wet while the interior is dry, causing some orchid roots to be unable to absorb water for a long time and shrivel, while the upper orchid roots reverse and grow upward, scattered and coiled in the surface soil. Many people, for convenience and to save trouble, connect a rubber hose directly to the tap and irrigate the orchid pot. This is very harmful: first, the tap water is untreated and the bleaching agent is harmful to orchids; second, the water temperature and soil temperature differ greatly; third, watering cannot be differentiated according to different situations. The spraying method is to spray water on the leaf surface with a spray pot, which can both increase air humidity and soil moisture and wash away dirt on the leaf surface. This method is often used during the orchid growing season. Do not spray too much each time; the standard is that the leaf surface is wet but does not drip. If too much water is poured into the leaf center, it will rot new seedlings if it remains for a long time. The nozzle holes of the spray pot should be fine and dense, and the water droplets fine and even. The soaking method, also called seep watering, is to put the bottom of the orchid pot into shallow water and let the water gradually moisten the potting soil. The soaking time must not be too long; as soon as the surface soil is seen to be moist, take the orchid pot out immediately. This method can keep orchid leaves clean. In dry seasons, the orchid pot can also be placed in a shallow water tray; the flower pot absorbs the accumulated water in the tray and then moistens the potting soil, thus maintaining relatively stable soil moisture. The disadvantage is that the bottom hole of the flower pot is blocked by water, so air permeability is affected to a certain extent.

6. Light and sunshine Light refers to the quality and quantity of sunlight, including wavelength, spectral composition and light intensity. Sunshine refers to the duration of sunlight; generally, irradiation for more than 14 hours is long-day, and less than 14 hours is short-day. Among plants, those that need long days to flower are called long-day plants; conversely, those that need short days to flower are called short-day plants. Light and sunshine are closely related to the growth and development of orchids.

Orchid light requirements:

There is a floral saying: "Shade for camellias, sun for peonies, half shade and half sun for four-season orchids." This shows that different flowers and trees have different sunlight requirements, and orchids need half-shade and half-sun light conditions. The effect of light on leaf color - Orchids have long grown in mountain forests and have developed a shade-tolerant habit, disliking direct strong light. When light is too strong, the leaf color becomes light green; if suddenly exposed to strong light, the leaf color quickly turns yellow, the leaf surface becomes rough, and the leaves may even scorch. With moderate light, the leaves are green with fine texture and luster; when light is too weak, the leaf color is dark green and loses luster. The effect of light on sprouting - The strength of light has a direct influence on the number of leaf buds and flower buds, the time they emerge from the soil, and their growth condition. When light is too weak, orchids produce more leaf buds and fewer flower buds, and their growth is poor. Therefore, starting some time before flower bud formation, appropriately increasing light can promote flower bud differentiation and achieve the goal of more flowers. The effect of light on flower color and flowering - The flower color of orchids is mainly determined by flower pigments, and violet light and ultraviolet light in the light are the main light energy forming orchid pigments. Therefore, when light is strong, the flower color is deeper and more vivid; when light is too weak, the flower color is extremely pale, and compared with normal, it may be mistaken for another variety. For example, in ancient times in Ningbo, Zhejiang, there was a kind of snow orchid produced on the shady side of a mountain; if planted in a pot and exposed to a little sunlight, it turned green, and so it was regarded as rare and precious, but now it is often encountered during wild collection and can also be obtained through artificial cultivation. Some people use this to practice fraud and pass it off as a new variety, and those without enough experience are often deceived. If other conditions are the same, the orchid pot placed in a position with stronger light blooms first; this is because the accumulated illumination and accumulated temperature first reach a certain value. Some people have experimented and found that extending the light duration to 14-16 hours can promote earlier flowering of medium-sized plants and small seedlings; but for mature orchid plants, a light duration of no more than 8 hours can promote flowering. For orchids that bloom in winter, short days and long nights and low temperature conditions must be met to promote flowering. For orchids that bloom in summer, long days and short nights and high temperature are required to promote flowering. For orchids with flower buds, to promote early flowering, light and temperature can be appropriately increased. In a small room, using a 100-watt light bulb can raise the room temperature by 3°C-5°C and can promote earlier flowering. The relationship between light and leaf variegation - Leaf variegation is the cultivation technique in which lines or spots appear on the leaves. Leaf variegation is related to light. Changes in light can be used to promote changes in leaf variegation. The method is to use robust growing orchid seedlings, with more than three plants connected together; before 9 o'clock in summer and before 10 o'clock in winter, place the orchid pot in the sun, insert a thermometer in the pot, and when it has been exposed to 30°C, move it into the shade. When it drops to 25°C, move it out again into the sunlight. Repeat this over a long period. One shade and one sun, one cold and one hot, is beneficial for the appearance of variable factors within the leaves. Over months and years, hard work pays off, and variegated leaves may appear. But the premise must be that hidden factors for leaf variegation exist within the orchid leaves; the change in sunlight merely promotes their manifestation.

Bases and methods for regulating orchid light:

Liking half-shade and half-sun light is a common characteristic of most Cymbidium plants, but there are also differences among orchid species. Species that bloom in spring, such as Cymbidium goeringii, Cymbidium goeringii var. longibracteatum and Cymbidium cyperifolium var. szechuanicum, need relatively weaker light, and the shading degree should be controlled between 70%-80%. Species that bloom in summer and autumn, such as Xia Hui and Qiu Su, need somewhat stronger light, and their shading degree should be controlled between 60%-70%; Cymbidium sinense needs about 85%. The light duration and intensity of spring, summer, autumn and winter are all different and should be treated separately, adjusting the shading degree well. Within a day, morning and evening sunlight can be allowed, while the fierce midday sun must be blocked and regulated, and on cloudy days the shading degree should be reduced. It is worth noting that after summer rainstorms, or when it first clears after long rain, orchid pots must absolutely not be exposed to the sun. Predecessor experience: if exposed to the sun immediately after rain, the water in the pot becomes hot and scalds the leaves and injures the roots. Although orchids are relatively shade-tolerant, they also have phototropism. In the same cultivation site, the flowers and leaves on the sunny side are always somewhat more luxuriant. Over time, the growth of flowers and leaves becomes uneven and they lean to one side. For symmetry and beauty, the direction of the orchid pots should be rotated and adjusted at intervals. If for special needs of modeling or composition, in order to express a specific poetic and pictorial meaning, the position of the light source can also be used to strengthen the tendency of flowers and leaves, achieving the beauty of dynamic balance and satisfying appreciation needs. To regulate shading degree and light duration, there are usually the following methods: Buildings - Establish greenhouses, orchid pavilions, waterside pavilions and orchid corridors to place orchids, using the light-transmitting and sun-shading properties of such buildings to regulate light. As long as the orchid pots are placed appropriately, the expected effect can be achieved; in the sunny places of these buildings, bamboo curtains or shade nets can be hung for regulation. For potted orchids kept on balconies, light is regulated by carrying them in and out; although it is hard work, it also cultivates enjoyment, and there is joy in combining flower growing with fitness. Building sheds - Shade sheds can be built with bamboo, wood, angle steel and the like as frames, covered with bamboo curtains, plastic film, shade nets and so on. Our method of regulating light intensity is to set up bamboo frames in the orchid nursery and install double-layer shade nets with 50%-70% shading rate on them; the upper layer is relatively fixed and only rolled up in winter, while the lower layer can be put down or rolled up. In midsummer use double layers; in spring and autumn use a single layer; at noon on clear days in summer and autumn use double layers, and on rainy days a single layer. In winter, it depends on the situation: on clear days let down the lower layer, on cloudy days roll up the lower layer, because in winter the light change inside the plastic greenhouse must not be too great; if too great, temperature and humidity will also change accordingly, which is unfavorable for orchid dormancy. In addition, before orchid flower cores are in bud and about to bloom, there must be moderate scattered sunlight, otherwise the flower color is dull and does not appear pretty. Building trellises - On the orchid cultivation site, build bamboo frames, wooden frames or reinforced concrete frames and let vines such as grape, honeysuckle, morning glory, Chinese trumpet creeper and cypress vine climb and spread over them, which can both shade and be beautiful and practical. Deciduous vines shade in summer and let light through in winter, which is a natural regulation. Planting trees - Around the orchid nursery, select and plant in combination evergreen trees, deciduous trees, bamboos and so on of different heights to regulate light intensity.

7. Fertilization Orchid roots have no fibrous roots, and there are symbiotic bacteria inside the roots.

The root bacteria absorb mineral nutrients from outside and supply them to the orchid, while orchid root cells provide water and organic nutrients to the root bacteria, forming a mutually beneficial and coexisting symbiotic relationship. But a stable balance must be maintained between them for luxuriant growth. Preparing suitable nutrient soil and fertilizing appropriately to maintain the balance between the two can promote vigorous orchid growth. Previously some people thought that since orchids grow in the mountains and are naturally elegant and pure by nature, clear water and fresh air alone could sustain them. Others loved orchids too deeply and were too impatient, often applying strong, high-concentration heavy fertilizer, causing results contrary to their wishes. Therefore, we must seriously explore scientific and reasonable fertilization.

(1) Types of fertilizer.

Fertilizers can be distinguished by their effective components, fertilizer properties, and fertilizer usage. By effective components, they are mainly nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer. Nitrogen is the main component of cell nuclei and proteins, and also an indispensable element in forming chlorophyll. Nitrogen fertilizer can make orchid leaves lush and robust; otherwise the leaves droop and soften, sprouting is difficult, and the reproduction rate is low. Commonly used nitrogen fertilizers include compost, * manure and urine, urea, green manure, ammonium sulfate, ammonium nitrate and so on. Phosphorus is also a main component of cell nuclei and directly affects cell division, chlorophyll formation and protein synthesis and transformation within plant cells; it can promote flower bud differentiation and growth, and promote large flowers, bright color and strong fragrance. Commonly used phosphorus fertilizers include superphosphate, potassium dihydrogen phosphate, phosphate rock powder, bone meal, rice-washing water and so on. Potassium directly participates in photosynthesis, can make cell physiology normal, and is also related to the synthesis of carbohydrates, proteins and fats. Potassium fertilizer can make orchid stems, leaves and roots grow robustly, make leaves tough and not easily broken, and enhance cold resistance and disease resistance, and can also increase flower fragrance. Commonly used potassium fertilizers include plant ash, potassium sulfate and potassium dihydrogen phosphate, all of which are fertilizers relatively rich in potassium. Besides the three main elements nitrogen, phosphorus and potassium, orchids also need various trace elements such as calcium, magnesium, iron, boron and zinc. These can be satisfied in the prepared culture soil and generally need not be added separately. But the demand for nitrogen, phosphorus and potassium is relatively large and must be solved through fertilization, repotting and soil changing. By fertilizer properties, they can generally be divided into organic and inorganic fertilizers. Organic fertilizers include compost, green manure, barnyard manure and cake fertilizer. Before use, organic fertilizer must be fully fermented, and the fermentation time must be at least more than one month. Organic fertilizer can improve soil structure, increase soil humus, make the soil well aerated and water-retentive, and its fertilizer effect is also long-lasting, able to gradually decompose and supply long-acting nutrients for orchid absorption. Inorganic fertilizer, also called chemical fertilizer, has high nutrient content, is clean and odorless, and can be diluted and used immediately without fermentation; it is convenient and quick-acting, but lasts only a short time, and long-term use can worsen soil structure. Generally, orchid growers oppose the use of chemical fertilizers. In fact, if orchids are mainly given organic fertilizer and supplemented with chemical fertilizer, the effect is still very good. By fertilizer usage, they can be divided into base fertilizer and topdressing. Base fertilizer is the fertilizer added to the soil when preparing culture soil or before planting, such as leaf mold, grass compost, and sorghum husk soil, which are both cultivation media for orchids and base fertilizer. Silkworm droppings, * manure, cow dung, bone meal, hair, cake fertilizer and so on can all be used as base fertilizer added to the bottom of the pot or turned under the soil as base fertilizer, but chicken manure and human manure are taboo.

(2) Topdressing is fertilizer applied during the growing season after orchids have been planted.

Generally, orchids are only repotted and given new soil 2-3 years after planting, and nutrients must be supplemented in between, so topdressing should be applied.

Fertilization time:

During the spring and summer growing period of orchids, to make orchids grow robustly and vigorously, more nitrogen fertilizer can be applied. If it is a leaf-variegated variety, then apply less or no nitrogen fertilizer, because dark green leaf color will affect the appreciation effect of leaf variegation. Do not fertilize when the summer temperature is above 30°C, because the potting soil temperature is relatively high, water evaporates too quickly, and the concentration of residual fertilizer increases, which is harmful to growth. If fertilized too frequently in summer, it easily stimulates autumn buds, and the plants that grow later are short and weak, and the following year's spring buds will be inhibited as a result. Do not fertilize when the temperature is below 10°C, because at this time they are in a semi-dormant state and do not absorb nutrients. Fertilizer should only be applied when sunlight and temperature are suitable and photosynthesis is vigorous. In winter orchids are in a dormant state, so there is even less need to fertilize. Before orchid new shoots grow to half-mature from the pseudobulb, the period before and after leaf buds emerge from the soil and during their elongation is the vegetative growth stage of orchids, when somewhat more nitrogen fertilizer should be applied and less phosphorus and potassium fertilizer. After vegetative growth comes reproductive growth; the nutrients produced by photosynthesis are stored in the pseudobulbs and leaves for flowering or new shoot growth. At this time, more phosphorus and potassium fertilizer is needed; applying appropriate phosphorus and potassium fertilizer can promote the pseudobulbs to become plump and mature, and to sprout and flower. If orchid leaves are pale and yellow and the plant is weak, it is mostly caused by fertilizer deficiency, and topdressing should be applied in time. But sometimes leaves also turn yellow due to too strong sunlight. Diseased plants should not be fertilized; fertilize only after the disease has been cured and they have recovered. Robust orchid seedlings can be helped by applying more fertilizer.

Ancient orchid growers had experience:

Never suddenly fertilize a thin orchid. Never leave a fat orchid thin for long. This means that a thin orchid that has never been fertilized cannot suddenly be given strong fertilizer, for it cannot absorb it and it is harmful. For orchids that are fertilized regularly, they also cannot go a long time without fertilizer. In short, uneven fat and thin is not beneficial to orchids. Usually Cymbidium goeringii, Cymbidium faberi and Cymbidium ensifolium begin fertilization in early May. In the dog days of summer, and from December to early February of the following year, do not fertilize. From May onward, apply dilute fertilizer once every 2-3 weeks until the end of September. In early September apply dilute fertilizer once to Cymbidium goeringii, and in late September fertilize Cymbidium ensifolium once. After each fertilization, clear water must be added the next morning, which facilitates orchid absorption and also prevents root injury from improper concentration. Generally, fertilization is not suitable before and after flowering.

(3) Fertilization methods.

Fertilization must mainly use organic fertilizer, which can make the soil loose with good structure and benefit orchid growth. Also apply thin fertilizer frequently, that is, the predecessor experience of "frequent and dilute," absolutely avoiding sudden and thick application, which is what people today mean by "small amounts, many meals." When applying, dilute the water-fertilizer appropriately, then pour it into the root zone with a spray pot, without contaminating orchid leaves. If chemical fertilizer is used, the concentration must be even lower. During the orchid growing season, a water solution of 2‰ urea and 2‰ potassium dihydrogen phosphate can be used as topdressing 2-3 times.

8. Ventilation.

Ventilation is also very important in orchid cultivation and management, but it is often overlooked by people. 146 Zhuhongxinsu (Beijing) With good ventilation and a constant supply of sufficient fresh air to orchids, photosynthesis can be promoted, nutrient production increased, metabolism promoted, and orchids made luxuriant. Ventilation in orchid rooms and shade sheds can regulate their temperature and humidity, making them beneficial for orchid growth and also reducing the occurrence of pests and diseases. Orchid brown spot disease and southern blight mostly occur in poorly ventilated environments. The orchid growing site must be open, with slightly higher terrain; the flower bench should not be too low, and always pay attention to ventilation. Orchids like gentle and soft breezes, not sharp winds, and overly cold or strong winds should be avoided by all means. Orchid pots should be placed sparsely rather than densely, and sufficient distance should be kept between orchid pots to prevent leaves from rubbing against each other in the wind and being damaged. If the site is small, the flower bench can be built in a stepped shape, which is good for ventilation and convenient for management and appreciation. Each orchid pot should not contain too many or too densely planted plants. If the plants multiply too densely, repot and divide them promptly. Frequently remove weeds, diseased leaves, fallen tree leaves and other debris from the orchid pots to facilitate ventilation within the pot. Daily work for ground-planted orchids through the four seasons: In spring, around Qingming, remove the plastic film from the shed, then water thoroughly once; several days later apply once a 15-20 times diluted duck feather water or fertilizer water made by fermenting cake fertilizer. At the same time, spray once with 1‰ omethoate (containing 40% effective ingredient) to kill insects. From May to July, apply once a month a fertilizer water made from 5% duck feather water or cake fertilizer. In August apply once a 3‰-5‰ compound fertilizer. After the beginning of autumn, no more fertilizer is applied. Autumn management is extremely important, and we summarize it in two words: autumn tempering. That is, after the beginning of autumn, orchids are no longer fertilized, water is controlled, and light is increased to promote early maturity. Generally, potted orchids should follow the golden rules of orchid growing: do not take them out in spring, do not expose them to the sun in summer, do not let them dry out in autumn, and do not keep them wet in winter. But ground-planted orchids are not entirely like this; in autumn they should be kept dry rather than wet. The reasons are: although the air is dry in autumn, ground moisture still rises from the soil, so severe water shortage will not occur; moreover, drought can temper the cold resistance of orchids and prepare them for overwintering. Autumn tempering can promote nutrients to gather in the pseudobulbs, increase the protoplasm concentration of the pseudobulbs, lower the freezing point, and prevent freezing injury. If orchid seedlings grow vigorously in autumn, then when a cold wave comes and the temperature drops sharply, they will inevitably suffer freezing injury. Ground-planted orchids cannot be moved indoors before severe winter arrives, so they can only survive through autumn tempering. November is a relatively busy season in the orchid nursery; the main work is to prepare for the overwintering of orchids. First, remove the upper shade net, then install the plastic greenhouse. At first do not close the two ends of the greenhouse, and only close them when the temperature drops noticeably; on clear days open them at noon for ventilation. This month, spray once with 1:1 Bordeaux mixture. Entering the severe winter season, first, do not water easily; second, appropriately increase light. So-called appropriate means that in winter some clear days have relatively high temperatures, especially with the warming winter phenomenon in recent years; at this time the lower shade net should be laid down so that the temperature inside the shed does not rise or fall suddenly. If the shade net is not laid down and the temperature inside the shed reaches 18°C-22°C for several consecutive days, some new shoots will begin to sprout, and once a cold wave arrives and the temperature drops sharply, they will undoubtedly be frozen. Therefore, in winter a dormant environment must be created for orchids, and dormancy must not be easily broken. In early spring, cold and warm air masses move frequently over the land, so management must be even more careful; otherwise orchid seedlings that have consumed nutrients through the winter are very likely to turn yellow and wither. Gradually and appropriately increase light, and do not remove the plastic film too early; only remove it after the weather becomes stable and clear in early April.

1. Potting soil requirements: It is best to use neutral to slightly acidic soil containing large amounts of humus, loose and well drained, with a pH generally around 5.5 to 6.5. In Sichuan, Emei Xiantu and "Xinghong brand" refined orchid growing medium are often used, and more commonly "bamboo root soil" and leaf mold from moist forests in mountainous areas are used to cultivate orchids.

2. Placement site: Orchids can be cultivated outdoors and on balconies in spring, summer and autumn, and a place with good ventilation, humid air and no environmental pollution should be chosen. Being near a pond or riverside is of course good, but at least there should be trees or bamboo groves and shade nets to reduce sunlight exposure and lower temperature. Orchid pots are best placed on wooden frames (or steel frames); if placed on the ground, bricks should be used as padding. Home balconies can also use small galvanized iron water tanks to store water, with bricks on top for cultivation, increasing humidity.

3. Appropriate shading: Most orchids belong to semi-shade plants, and most species fear direct sunlight and need appropriate shading. In early to mid-April, orchid pots can have the net removed and windows opened, receiving more sunlight to promote growth. In May, aside from the midday sun, they can receive 6 hours of light; from June onward, shade all day; after October, aside from the midday sun, they can be fully opened for care. Remember the proverb: "More shade, better leaves; more sun, better flowers."

4. Reasonable fertilization: Orchids are naturally "vegetarian," and fertilization should depend on the chosen potting soil and growth condition. Those growing luxuriantly without disease can be fertilized, while those growing poorly should not be fertilized or only lightly fertilized. Newly planted orchids whose roots have not fully developed must wait 1-2 years before fertilization. Generally in June-July, when orchid leaf buds have elongated to about 1.5 cm, apply once every three weeks a fully fermented liquid fertilizer (dilute concentration is suitable, about 10%). Chemical fertilizer is taboo; in high-temperature seasons fertilization is not suitable. From August to September, apply a diluted liquid fertilizer once every two to three weeks. Each fertilization of orchids should be carried out in the evening, and clear water should be watered in the morning, called "return water."

5. Appropriate watering: For watering orchids, rainwater and spring water are best; tap water or rice-washing water must be left overnight before use. When watering, pour from the edge of the pot, and do not pour into the flower buds. The amount of watering should be determined according to air temperature, the degree of dryness or wetness of the potting soil, and the growth condition of the orchid. Water more when there are many leaves, less when leaves are fine. In April-May, when new buds have not yet emerged from the soil, the potting soil should be somewhat dry; if too wet, new buds easily rot; from June to September, which is the growth period of orchid new shoots, the amount of watering should be increased, watering once every morning on clear days or once a day, and absolutely avoid watering under the fierce midday sun. In autumn, appropriately reduce the amount of water, and leaf-surface misting can be used to keep the potting soil moist; in winter, water should be controlled even more, and it is suitable to maintain "eight parts dry, two parts wet."

6. Evening misting: Orchids originally grow in humid air environments, so in dry seasons, besides shading, evening misting must also be done to increase air humidity and lower temperature; water can also be poured on the ground (bench surface) of the potted orchids; "one cold and one hot" can further stimulate orchid growth.

7. Wind and rain protection: The "February ghost wind" causing old leaves to turn yellow and fall is a normal phenomenon, and dead branches and withered leaves can be cut off. Orchids can be exposed to light rain, but must avoid plum rain, rainstorms or continuous rain, otherwise the heart and leaves easily rot. In seasons with a lot of rain, a small amount of plant ash can be appropriately sprinkled.

8. Pruning and flower removal: In orchid cultivation, withered, yellowed, broken leaves and diseased leaves should be cut off frequently to improve ventilation. For precious orchids, if there are too many flower buds, keep only the strong ones, with 1-2 flower buds per pot being appropriate. Cymbidium goeringii (Spring Orchid) flowers should be removed half a month after opening, and precious orchids after 7 days, so that the spring leaf buds grow vigorously and produce even better blooms the following year. For Cymbidium ensifolium (Summer Orchid), when the last flower on the inflorescence has been open for one week, cut it off 3 cm above the pot surface.

9. Cold protection and warmth: Because orchid varieties differ, their places of origin vary, and their cold resistance differs as well, the time to move them indoors in winter and their indoor placement also differ. Cymbidium kanran, autumn orchids and Cymbidium sinense (Bao Sui Lan) grow in the south, so they should be moved indoors (or have windows closed and netting drawn) when the temperature reaches 5°C, and placed in a south-facing sunny spot as much as possible. Spring and summer orchids have stronger cold resistance and can stay out until 0°C before being moved indoors, placed on the northeast side. On clear, windless days around noon, open windows on the south or southeast side and draw the netting for ventilation. Autumn orchids should not have windows opened on clear days at 1-2°C. Of course, if a greenhouse is available, electric lighting can be used for heating.

10. Disease and pest control: Potting soil should generally be sterilized (sun exposure also works) to prevent disease. Orchids are most prone to southern blight (Sclerotium rot) in rainy, hot seasons; for a small amount, it can be brushed off with a damp cloth, and for many pots, a 500-800 times dilution of Bordeaux mixture or thiophanate-methyl can be used, sprayed once every 7-10 days. Among pests, scale insects (commonly known as "orchid lice") occur most; during the hatching period, use a 1% omethoate and 25% phosmet EC 1000 times solution, sprayed once a week. To treat the symptoms you must treat the root cause: pots should be spaced appropriately, placed at varying heights, with increased ventilation, to reduce disease occurrence.

However, different orchids have different cultivation methods.

Several aspects to note in orchid cultivation

China has a long history of orchid cultivation, and our predecessors accumulated rich experience in orchid growing for us. We should thoroughly understand the experience of our predecessors, absorb its essence, and deeply recognize that: cultivation environment, growing medium, watering, fertilizing, and pest and disease control are the five major links in orchid cultivation and management.

1. The choice of environment is relatively important. Cymbidium faberi (Huilan) mainly grows under shrubs in subtropical mountain forests, which has cultivated the orchid's growth habit of preferring half shade and half sun and enjoying moisture and ventilation. As long as you grasp the orchid's growth patterns and provide or create environmental conditions close to the orchid's natural growing environment, spring orchids and Huilan can be cultivated anywhere in the country.

2. The use of growing medium. According to cultivation experience in various places, as long as it is slightly acidic, any growing medium (including soilless cultivation) can grow orchids well; the issue is that different growing media require different management methods. It is best to use clay pots or Yixing clay pots for the pots, because orchids are aerial-root plants and pot breathability is very beneficial to orchid growth.

3. Reasonable watering is the key to growing orchids well. The water used for watering orchids must be clean and slightly acidic; never water with sewage containing pathogens. Watering methods should differ depending on the plant. Loose mountain soil holds sufficient water, and granular soil plus volcanic rock with stones also absorbs water fairly fully without waterlogging. After different growing media have been watered thoroughly once, when the pot surface looks dry and about one centimeter of the growing medium has turned whitish. To increase air humidity, you can spray the pot surface, increasing moisture in the upper layer of the growing medium so that the orchid grass and pseudobulbs maintain a certain moisture; when the whole pot from top to bottom has not dried out completely, water heavily and thoroughly again.

4. Fertilizing: On the basis of good watering, in order to promote better growth of the orchid grass, fertilizing becomes even more important. Organic fertilizer, that is, farmyard manure, should be diluted and can be applied once every ten days or so; other inorganic fertilizers (chemical fertilizers) should be used according to the instructions. During the orchid's growing period, foliar fertilizer can be applied as a top dressing outside the roots. Base fertilizer is also very important; when repotting and changing soil, as long as the fertilizer does not touch the orchid roots, an appropriate amount of base fertilizer can be added. Too much fertilizer easily burns the orchid roots and causes black spots; if fertilizing is done properly, it can produce strong seedlings and good flowers. The general requirement for fertilizing orchids is small amounts, clear, dilute and light, truly achieving "thin fertilizer applied frequently."

5. Pest and disease control: Insect pests are easy to prevent, but fungal diseases are hard to cure. If scale insects and other pests are found on orchid grass, use omethoate or deltamethrin and spray according to the instructions, preferably in combination, 2-4 times a year. General fungal diseases such as black spot can also be treated with fungicides such as copper hydroxide, thiophanate-methyl, and chlorothalonil according to the instructions, with regular alternating treatment and preventive spraying every 15-20 days during the growing period. If Bayras soft rot (rot coccus disease) is found, it is a terminal disease among orchids that cannot be cured fundamentally; once discovered, remove it promptly. Therefore, when purchasing orchid grass, you must pay attention and absolutely do not buy lower-priced diseased plants, thereby affecting other precious orchid grass.

Different orchid species have different temperature requirements. The most suitable temperature for vegetative growth of Chinese orchids is 20-30 degrees, the adaptive temperature range is 5-35 degrees, and the temperature for the reproductive period is generally between 5-15 degrees. Nighttime is 3-5 degrees lower than daytime. When the summer temperature is above 30 degrees, the higher the temperature, the more orchid growth is hindered. But under ventilated conditions, Chinese orchids are not harmed by short periods of temperatures as high as 35-42 degrees. When the temperature is below 12 degrees, growth is slow. When the temperature is below 12 degrees, Chinese orchids shift to reproductive growth. Cymbidium sinense (Molan) originally grew in subtropical mountain forests; in summer, daytime temperatures can reach around 32 degrees, while at night it is cooler, with temperatures generally not exceeding 20 degrees, and winter temperatures not dropping below 10 degrees. Cymbidium kanran and Cymbidium ensifolium originally grew in transitional subtropical mountain forests. Cymbidium goeringii and Cymbidium faberi mostly grow in temperate mountain forests; in temperate regions, summer temperatures can reach around 38 degrees, but in shaded mountain forests, daytime temperatures do not exceed 30 degrees, and nighttime is around 18 degrees. In winter, under short-term snow cover, the surface temperature still exceeds 5 degrees, with no effect on flowering. Indoors, they can overwinter at around 0 degrees. The suitable growth temperature for Cymbidium goeringii 'Chunjian' is 18-28°C, not exceeding 35°C in summer, and not lower than minus 2°C in winter, with a reproductive growth temperature of 8-18°C. The temperature requirements for Cymbidium lianpan generally are not lower than -12°C in winter; during the reproductive period in spring and autumn, the temperature should not be lower than 12°C; during the summer growing period, temperatures mostly between 15°C-32°C are appropriate, with 35°C or above being the critical line for growth, beyond which growth stops again.

The driving force of orchid life - light

"All things grow by the sun." This sentence highly summarizes the enormous role of light in the growth and development of living things, especially plants, and in the continuation of generations. Orchid grass itself relies on the photosynthesis of green leaves to obtain energy to maintain and continue life and reproduce; sunlight is the driving force of orchid life. But for orchids, which require a half-shade, half-sun habit, excessively strong light is also harmful to orchid growth. We must regulate and control the light suitable for orchids according to the temperature, humidity of different seasons, and the growth habits formed under the ecological environment of various orchid grasses, so as to satisfy and benefit the survival and growth of orchids. Below, regarding the close relationship between light and orchid grass, I will discuss some immature views and explore them with fellow orchid growers, which may be of some use for growing orchids well:

Below we explore from five aspects:

1. The relationship between light and orchid grass growth.

2. The influence of light on orchid leaves, buds and flowers:

3. The effect of light on orchid fertilizing and sterilization.

4. The light intensity for orchids.

5. Artificial regulation of light.

1. The relationship between light and orchid grass growth.

Suitable light can promote normal orchid growth: orchid growth relies on the photosynthesis of green leaves to obtain energy to maintain and continue life; light's effect on photosynthesis in Cymbidium plants is accomplished through light quantity and light quality.

① "Light quantity." That is, the intensity of light. Plant photosynthesis changes with changes in light intensity, and photosynthetic intensity is directly proportional to light intensity. That is, when light intensity doubles or halves, photosynthetic intensity also doubles or halves. Through the chemical action of chlorophyll in orchid leaves, light absorbs carbon dioxide and releases oxygen to increase the nutrients needed by the orchid body. At night, the bulbs and roots carry out digestion and decomposition, converting carbon dioxide into sugar, and then forming various needed proteins, which are transported to all parts of the plant through the flow and pressure of water and air, allowing potted orchids to grow shoots and bloom. Photosynthesis has a heat limit and a cold limit, that is, the highest temperature and the lowest temperature, also called the critical points of photosynthesis. Too much and too strong sunlight, exceeding the critical point, can cause leaves to become dwarfed and yellowed, or even age prematurely and stop growing grass, gradually declining and dying. Conversely, if light is insufficient, although the plant still grows, the nutrients produced are not enough, which is equally unfavorable to the healthy growth of orchids. Therefore, the levels of the plant's light compensation point and light saturation point directly affect the accumulation of organic matter and healthy growth of orchid grass. To make crops grow well, attention should be paid to lowering the light compensation point and raising the light saturation point. The usual measures are: sun plants should be reasonably densely planted, controlling population development, ensuring the plants have enough light; if natural light is insufficient, increase artificial light; shade plants should be moderately shaded on the premise of satisfying their photosynthetic intensity as much as possible. Letting orchids have relatively abundant light of sufficient duration is beneficial.

② "Light quality." The regulation of light should consider not only light quantity but also light quality. The intensity of plant photosynthesis varies with light quality. Sunlight contains seven kinds of visible light as well as invisible light such as ultraviolet rays. Orchid leaves respond only to red, orange, yellow, and blue-violet series of light. Different colors of sunlight produce differences in the intensity of plant photosynthesis; red light and blue-violet light are more efficient, while yellow-green light is lower. Not only does photosynthetic intensity differ, but the photosynthetic products are not entirely the same either. For example, when plants grow under blue-violet light, the amount of protein and fat in their photosynthetic products increases, while under red light more carbohydrates are formed. Infrared light irradiation is beneficial to plant cell division, showing as thickening in plants; far-infrared light irradiation is beneficial to plant cell elongation, showing as growing taller in plants; ultraviolet light irradiation is beneficial to shortening orchid internodes, showing as dwarfing in plants. Therefore, orchid supplemental lighting should set different light qualities according to the specific growth conditions and requirements of orchid seedlings. (Ordinary incandescent lamps have less blue-violet light than the sun but more infrared light; fluorescent lamps have more blue-violet and green light but less red light; the visible light portion of xenon lamps approximates sunlight, but ultraviolet and infrared light are greater than in sunlight.) Orchid cultivation generally uses more red light and blue-violet light. Experts suggest that supplemental lighting for Chinese orchid cultivation should use more red light. Of course, if conditions permit, choosing plant lights specially designed for orchid supplemental lighting is even better.

In short, according to the type of photosynthetic products needed as described above, one should comprehensively consider and make up for deficiencies, choose a suitable light source, and promote the normal growth of orchids.

2. The influence of light on orchid leaves, buds and flowers:

1. The influence of light on orchid leaves.

① Orchid leaves under different light: Orchids have long grown in mountain forests and developed a half-shade, half-sun habit, preferring diffused light and disliking direct strong light. When light is too strong, orchid grass leaves tend to be shorter, thicker and stiffer, with a rough leaf surface, and the leaf color turns pale green. If there is sudden strong light, the leaf color quickly turns yellow, the leaf surface becomes rough, and the leaves may even scorch. With moderate light, the leaves are green with fine texture and luster, and the growth is robust. When light is too weak, the leaf color is emerald green, and the leaf texture is thin and long without luster. In short, the stronger the light, the yellower the leaf color; the weaker the light, the deeper the green leaf color. Too strong or too weak will both affect the perfect growth of orchid grass.

② Changes in light can promote the appearance of leaf variegation. Plants with the possibility of variegation can receive a longer light duration; for linear-variegated orchids, sunlight from 6 to 9 in the morning is best. Someone did an experiment: before 9 o'clock in summer and before 10 o'clock in winter, place the orchid pot in the sunlight, insert a thermometer into the pot, and when it reaches 30°C move it into the shade. When it drops to 25°C, move it out into sunlight again. Repeat this over the long term. One shade and one sun, one cold and one hot, is beneficial to the appearance of variable factors within the leaves; over the years, variegated leaves may appear. But this must be premised on the existence of hidden variegation factors within the orchid leaves; the change in sunlight merely promotes their appearance and has no necessary connection. White-spotting cells are the decisive factor and determining effect in orchid linear variegation changes.

2. The influence of light on sprouting. Light can increase the sprouting rate of orchid grass. Orchid grass sprouting cannot rely solely on water and fertilizer management; appropriately increasing light is very crucial. The sprouting rate is generally high when receiving strong sunlight; strengthening light can not only increase the sprouting rate but also make new shoots stronger.

① Shallow planting of orchids produces more sprouts. Orchid growers generally believe that for orchid grass, "deep planting is not as good as shallow planting." This is because when orchids are deeply planted, the bulbs are buried deep and receive less light; under the same fertilizer, water and management conditions, deeply buried bulbs are small and sprout less in spring. With shallow planting (with half the bulb exposed outside the soil), the bulbs are large and sprout more in spring. This is closely related to the spectrum and the length of light duration. It also demonstrates the principle that light can increase the sprouting rate of orchid grass.

② Light can promote flower bud differentiation and achieve the goal of more blooming. Because light is the source of nutrients for flower bud differentiation and growth. The strength of light has a direct impact on the number of leaf buds and flower buds, the emergence period and growth conditions. Orchids with sufficient light produce more nutrients through photosynthesis, have more flower bud differentiation, bloom more, have deeper flower colors, and have large, good flower shapes. Conversely, orchids with too weak light, although the plants grow luxuriantly, do not produce enough nutrients, and grow more leaf buds and fewer flower buds. Even if they bloom, the flower color is paler, the flower shape is poorer, and the growth is poor. Therefore, starting a period before flower bud formation, appropriately increasing light can promote flower bud differentiation and achieve the goal of more blooming.

3. The influence of light on flowering:

① Light strength and flower color changes. Sunlight is the fundamental source of color for all things in the world. The seven colors of the rainbow can change in countless ways, and the original colors of orchids are composed of ever-changing original light. Violet light and ultraviolet rays in light are the main light energy forming orchid pigments. Therefore, sunlight has a direct influence on colored orchids. Strong light makes flower colors deeper and more vivid; excessively weak light makes flower colors extremely pale. For example, to make the flower color of the red-flower series beautiful, sunlight can be slightly strengthened; to make the blue series produce beautiful flowers, sunlight should be reduced. Colored flowers should be appropriately shaded during the flowering season, because under sunlight red and green light are not absorbed, while petal-form flowers should be more exposed to sun to thicken the petals. When growing colored flowers, paying attention to and controlling light well during cultivation can make the flower color more beautiful. Green and white flowers should reduce light; red, yellow, pink and purple need increased light. For example, if Cymbidium goeringii blooms in shade, the flower quality and color are better than when blooming in sun (except colored flowers), and the flower stalk is also longer. For Cymbidium faberi and Cymbidium ensifolium, stronger light is beneficial to flowering, with larger flowers, good color and fragrance. Therefore, controlling and regulating reasonable light is a necessary maintenance technique to fully express the best flower color.

② The influence of light on orchid opening.

For orchid grass with flower buds, to promote early or delayed flowering, this can be achieved by regulating the length of light duration. Appropriately extending light and increasing temperature. For example, using a 100-watt bulb or infrared lamp in a small room to raise room temperature by 3°C-5°C can promote earlier flowering. Similarly, orchid grass with flower buds placed in a location with weak light and low temperature can also delay flowering. For orchid grass that has already formed flower buds, appropriately extending sunlight and raising temperature, or using a 100-watt bulb or infrared lamp in a small room to raise room temperature by 3°C-5°C, can accelerate the flowering period and make it bloom earlier. Conversely, reducing light in a low-temperature environment can delay the flowering period, because raising or lowering temperature can accelerate or slow the physiological activities within the plant. Using this biological characteristic, some people have experimented: extending light duration to 14-16 hours can promote earlier flowering of medium plants and small seedlings; but for mature orchid plants, a light duration of no more than 8 hours can promote flowering. Appropriately adjusting light intensity can make orchids open at the right time, especially for species that bloom in spring; they generally form flower buds as early as July-September of the previous year, and after passing through the winter dormancy stage, appropriately increasing light and raising temperature can make them bloom earlier, catching up with the Spring Festival holiday. Conversely, appropriately reducing light and lowering temperature can also delay flowering for timely orchid exhibitions. In short, regulating light intensity can make orchids open at the right time.

3. The effect of light on orchid fertilizing and sterilization.

1. The relationship between light and fertilizing. Generally, for various orchids in different seasons and at each growth stage, how to shade and supplement light so that orchids receive suitable light intensity is of concern to everyone. However, in the process of orchid cultivation, how to correctly handle the relationship between fertilizing and light may not necessarily be taken seriously, yet this is equally very important for the vegetative growth of orchids. The strength or weakness of light will lead to the strength or weakness of assimilation. If light is too weak, the assimilation of leaves is also insufficient. This leads to poor digestion of nitrogen fertilizer during the day, less accumulation of sugars and starch, and therefore less decline at night. Over time, leaves become very long while roots remain very short. If light is too strong, leaf assimilation also becomes too strong. Orchid grass respiration increases, consuming excessive nitrogen fertilizer, causing leaves to become short, small and yellowed. At the same time, abundant sugars and amino acids cause excessive growth of pseudobulbs and roots. The causes of these two poor growth conditions may be many-sided; light is not the only factor. (For example, long-term dryness of the orchid pot, too much phosphate fertilizer, high-carbon growth, small day-night temperature difference, nitrogen deficiency and other conditions can also produce these problems.) Failure to correctly handle the relationship between fertilizing and light is also one of the important reasons, and must be noted. The maintenance measures when encountering this situation are: when orchids show a "long leaves, short roots" state, light intensity must be gradually strengthened, organic nitrogen continuously supplied, and water supply reduced. After new roots grow out, they will slowly return to normal. When orchids show a "small leaves, strong roots" phenomenon, light should be reduced, and sufficient inorganic nitrogen continuously supplied. This can both lower sugar content and promote protein synthesis, and the new grass produced can then return to normal.

Practice has proved that only under conditions of sufficient light can orchids absorb nutrients, so when fertilizing orchids there must be moderate sunlight; the best fertilizing time is the morning of good weather. When applying chemical fertilizer, the light intensity selected should be relatively high; when applying organic fertilizer, it should be relatively low.

2. Sunlight is a good weapon for sterilizing orchid grass and preventing disease. Light can not only raise temperature; the ultraviolet rays in the spectrum can kill and prevent the breeding of fungi, pathogens and viruses. Pathogenic bacteria generally find it very hard to survive under intense sun exposure. Therefore, exposure to the sun can sterilize and disinfect pots and growing media. But for the sterilization and disinfection of orchid grass, the use of sunlight must be timed. For example, sun orchids in winter, letting the whole orchid plant bathe in sufficient sunlight; in summer, avoid the intense sun at noon and in the west. Light can also close orchid leaf stomata, blocking pathogenic fungi that easily invade through stomata. We have found that orchid plants with good light have strong disease resistance, while orchid plants with poor light, because their stomata are often open, are prone to infection by invading pathogens; orchid plants with insufficient light are prone to pests and diseases. Using sunlight for sterilization and disinfection has always been advocated by orchid growers. Orchid photosynthesis, like other biochemical processes, cannot exist in isolation, and at the same time is restricted and influenced by external environmental conditions. These external factors are: light intensity, concentrations of carbon dioxide and oxygen, wind speed, temperature, water supply, inorganic nutrients, and pollutants in the atmosphere and soil, etc. In addition, photosynthesis is also affected by the plant's own internal factors, such as chlorophyll content, degree of stomatal opening, and the physiological state and structure of the leaves themselves. By improving these internal and external factors, the goal of increasing plant photosynthetic efficiency can be achieved. Promote healthy development, growth and flowering of orchids. In summary, according to the growth habits of orchids, giving appropriate light can improve fertilizing efficiency, enhance disease resistance, and benefit the healthy growth of orchid grass. For this reason, orchids with weak plants, no flowering and susceptibility to pests and diseases must have strengthened light.

4. The light intensity for orchids.

1. Orchids grow in mountain forest areas, and the ecological environment has cultivated the need for half-shade, half-sun light conditions. There is a folk flower saying: "Shade for camellias, sun for peonies, half shade and half sun for evergreen orchids." This shows that orchids have a half-shade, half-sun light habit, and the growth of all kinds of orchids cannot be separated from light. This is also a "common characteristic" of orchid plants.

2. The light requirements of various orchid grasses are not entirely the same. Because of differences in ecological environments, various orchid grasses differ in strong or weak light requirements. Generally speaking, Cymbidium faberi and Cymbidium ensifolium need more light for growth and can be shaded less. But in the vigorous summer and early autumn, strong direct light will still scorch some leaves, causing the leaves to turn brown, or even the leaves to scorch yellow and wither; at this time shading is necessary, shading out 70%-80% of sunlight. Cymbidium kanran and Cymbidium sinense relatively need less light, and in summer should be shaded from 80%-85% of sunlight. For newly potted grass, diseased and weak seedling grass, old grass, particularly delicate grass, and grass that has not been hardened and has long been in half shade and half sun, shading must be given during the growing period. For marginal-variegated grass, striped grass, crystal grass, and if they are transparent bodies, etc., they must not receive relatively strong direct light. They must be shaded when sunlight is strong. The amount of shading is also a rough estimate, because different varieties under the same species do not have absolutely identical light requirements; for example, within the same species, variegated grass, colored flowers, and strong versus weak plants all differ in light requirements. This is the "individuality" of orchid plants. The grower needs to observe carefully to correctly grasp the appropriate light for various orchid grasses.

3. Orchids can be roughly divided into three categories: sun-loving, semi-shade and shade types. As well as long-day and short-day types. Long-day orchids bloom as daytime gradually lengthens and nighttime gradually shortens; for example, Cymbidium ensifolium and summer Cymbidium kanran that bloom in late spring and summer, etc.; short-day orchids are the opposite, blooming as daytime gradually shortens and nighttime gradually lengthens, such as Cymbidium goeringii, Cymbidium goeringii 'Chunjian', Cymbidium faberi, and Cymbidium sinense that bloom in late autumn and winter.

4. Reference values for the optimal sunlight intensity of various orchids (unit: LUX)

Orchid species Sunlight range Optimal light intensity Variegated grass light intensity

Evergreen Orchid (Sijilan) 10000-14000 **** 10000

Huilan 9000-13000 11000 9000

Spring Orchid (Chunlan) 8000-**** 10000 8000

Chunjian 8000-**** 10000 8000

Lianpan Orchid 8000-**** 10000 8000

Kanran 8000-**** 10000 8000

Molan 4000-****5000 4000

"Fairburn and Pringle pointed out: no one can propose the best light quality and light quantity for orchid growth and development, because this is a complex factor involving light, temperature, different times, carbon dioxide concentration, day length, nutritional conditions, humidity, and the day-night temperature difference, etc." ----Excerpted from Wu Yingxiang, "Chinese Orchids." So the sunlight intensities above are only reference values.

5. The light intensity for orchid grass changes with the seasons: In winter and spring, orchids should see more sunlight and basically can go without shading; in summer and autumn, sunlight before 8-9 in the morning should be more fully received, and the west sun in the afternoon must be avoided, otherwise orchids are prone to disease. Sunlight and temperature have a great influence on orchid reproduction. If there is no sunlight for a long time in winter and the temperature is relatively low, it will affect the development of winter buds, leading to fewer and poorer-quality seedlings in spring and affecting the grass increase rate for the whole year.

6. Orchids like light in a cool environment. Generally, shading begins when spring turns to summer and ends only after late autumn. In summer, shade 40-50%; in late autumn, winter and spring, they should fully receive light. Generally speaking: at 20-25°C, under direct sunlight, the chemical reaction between chlorophyll in orchid leaves and light is fast, and the grass grows vigorously. Above 30°C, chlorophyll in the leaves automatically decreases, the leaf color becomes lighter, and a gray visible film gradually forms to reflect sunlight and prevent scorching. This condition can only be maintained for a relatively short time; if it lasts long, it starts from the tip of the orchid leaf first, and the whole plant gradually dies, especially old grass, which first turns yellow and then scorches. Therefore, the length of time orchids receive light changes with high or low temperature, in an inverse relationship.

7. Orchids like morning sunlight. When the morning sun first rises, the sunlight angle is low and the orchid's illuminated area is large. Also, because morning sunlight is blocked by morning mist, the light is relatively soft, and direct will not scorch orchid leaves. After nighttime nutrient accumulation, orchids have the strongest photosynthetic capacity in the morning.

5. Artificial regulation of light.

Too strong or too weak light is unfavorable to orchid growth, and orchid light varies greatly with season, weather, region, environment, etc. If light is therefore too strong, artificial shading must be adopted, adjusting the shade density to reduce the orchid's light. If light is insufficient because of this and affects the healthy growth of orchid grass, artificial lighting must also be adopted to appropriately supplement light for orchid grass, letting it have relatively abundant light of sufficient duration. In short, to give orchid grass appropriate light, artificial regulation is necessary.

1. The basis for regulating orchid light:

① Regulate the appropriate light for various orchid grasses according to differences in light requirements among orchid species. Orchid varieties differ, and their photosynthesis and optimal temperatures also differ. For example, different orchid species and variegation types will differ at different times and in different regions. On blazing sunny days in midsummer and golden autumn, regarding shading requirements, the shade density for Cymbidium ensifolium is 60%-70%; Cymbidium goeringii and Cymbidium faberi require 70%-80% shading in summer, while Cymbidium sinense needs about 80-85%. Ordinary linear-variegated orchids can be about 80%, while high-grade linear-variegated orchids, crystal-variegated orchids, and pattern-variegated orchids should be about 90%. Flower-art orchids and ordinary linear-variegated orchids can receive full light before 9 a.m. and after 4 p.m. on clear days; high-grade linear-variegated orchids, crystal-variegated orchids, and pattern-variegated orchids should be half shaded. In high-temperature "furnace" regions, the shading density should be correspondingly increased by more than 5%. In winter and spring, appropriately increasing the light amount by 20% is more beneficial to orchid growth.

② Adjust the shade density according to the light duration and light intensity of different seasons. From late spring to summer and autumn, shade 40%-50%; in winter and early spring, 10%-20% light. Insufficient light will make orchid leaves soft and deep in color, and make the leaves at the rhizome bend downward or outward. Especially during the leaf-pulling period, it makes leaves grow rapidly. Conversely, too much light will make leaves turn yellow or chlorophyll be destroyed, causing cell death, and too much light makes leaves shorter and thicker and open prematurely or bend outward. Therefore, except in early winter and midsummer, move orchids outdoors in the morning until 9-10 o'clock, so they get sufficient light. As the angle at which sunlight strikes the earth shifts, light duration, light intensity, etc. will all change. In the short and weak light of winter and spring, except that high-grade linear-variegated orchids, crystal-variegated orchids and pattern-variegated orchids need 60%-70% shading, all other orchids can have full light, or be half shaded from 10-14 o'clock on clear days. In the long and strong light of summer and autumn, the shading time and density for orchid grass must also be adjusted accordingly.

③ According to weather changes. In changeable weather such as clear, partly cloudy, cloudy, overcast, rainy and snowy days, light also changes frequently accordingly. Therefore, the shading degree must be appropriately adjusted with weather changes and light strength. In particular, high-grade linear-variegated orchids, crystal-variegated orchids and pattern-variegated orchids are not tolerant of strong light; if the shading degree is not adjusted promptly, it often leads to sunburn damage. In addition, if a fixed shading density is always maintained regardless of light strength, the sprouting rate and flowering rate of orchid plants will naturally not be as good as with timely adjustment.

④ According to the day's sunlight changes: clear turning overcast, overcast turning clear, clear turning rainy, clearing after rain, etc. Morning and evening sunlight can be allowed to shine freely; the noonday blazing sun must be blocked and regulated; on cloudy days the shade density should be reduced. It is worth noting that after summer rainstorms, or when it clears after long rain, orchid pots must absolutely not be exposed to the sun. Predecessors' experience: "If exposed to the sun right after rain, the water in the pot is hot, which scalds the leaves and harms the roots."

⑤ Regulate specifically according to differences in climate, light intensity, etc. in different regions. China has a vast territory, and climate cold and heat and light intensity differ, with relatively large differences; however, the standards and requirements for strong, weak and appropriate light for orchid growth are still unified, and specific regulation can be carried out according to the local climate.

⑥ Regulate according to high or low temperature. Orchid photosynthesis is closely related to temperature. Generally speaking, Chinese orchids carry out normal photosynthesis at 5-36°C, with the optimal temperature being 18-28°C; at temperatures as low as 0°C and as high as 40°C, these are the limits, and orchid photosynthesis is inhibited. Starting from the low-temperature limit, photosynthesis strengthens as temperature rises. Beyond the optimal point, photosynthesis declines; above 36°C photosynthesis is very weak, and when reaching the 40°C limit, photosynthesis stops. When the temperature is high, use shading to cool down; when the temperature is low, use heating equipment to raise the temperature, thereby achieving a more suitable temperature, promoting orchid photosynthesis, and ensuring healthy and rapid growth of orchids.

⑦ According to the phototropism of orchid grass. Orchids are phototropic, so the direction of the orchid pot should be rotated and adjusted at intervals, to avoid the plant's leaves leaning to one side. In particular, for the side with new plants, during the budding period it should face the direction with sufficient light, to facilitate sprouting and healthy growth of buds. If for the special needs of modeling or composition, to express a specific poetic and picturesque meaning, the position of the light source can also be used to strengthen the inclination of flowers and leaves, achieving the beauty of dynamic balance and satisfying appreciation needs.

⑧ Regulate according to the growth condition of orchid grass. Generally speaking, if the leaf color is pale green and orchid leaves are weak and leggy, then light is too strong; if they appear yellow-white or even scorched yellow and withered, then light has exceeded the orchid plant's tolerance. Conversely, if the color is dark green or deep green without luster, it indicates light is too weak. Regulate shading well according to the growth condition of orchid grass. In addition, if stems and leaves are relatively dense and soft, with many leaf buds and few flower buds, then light is insufficient; conversely, if stems and leaves are sparse and firm, with few leaf buds and many flower buds, then light is too strong. Both are abnormal and need timely adjustment.

⑨ Regulate light according to the orchid's growth stage; during the growing period, supplemental light time should be longer, and during the dormant period, a little less.

⑩ Based on professional testing. (Excerpt)

(1) The light intensity for well-growing orchids is 4000-5000 Lux (lux, the unit of light intensity), and their sprouting rate, flowering rate, leaves and leaf color are all excellent.

(2) From the practice of professional testing, it has been found that orchids have a saturation point for light requirements. After light reaches the saturation point, even better sunlight is harmful rather than beneficial to orchids.

(3) Plants most easily absorb red and blue light, and a balanced combination of red and blue light is especially important for photosynthesis. According to experiments, red light can promote orchid growth, while blue light is indispensable for thickening leaves, accelerating plant development, and regulating stomatal opening. Green light also cannot be ignored; it can promote oxygen production, thereby helping orchids better store nutrients.

(4) A certain intensity of long-wave ultraviolet light is also indispensable; it helps form anthocyanins and inhibit the elongation of branches and leaves.

2. Methods for regulating orchid light:

First, shading. In nature, orchids mostly grow in cool, shaded mountain forest environments with scattered sunlight; semi-shade and shade types account for more than four-fifths of all orchid plants. Therefore, when light is too strong, shading must be used to weaken the light.

(1) Plant shading. Imitating the natural environment, using plants for shading is one of the relatively ideal methods. The method is: on the orchid cultivation site, set up bamboo frames, wooden frames or reinforced concrete frames, and let vines such as grapes, honeysuckle, morning glory, Chinese trumpetcreeper, and cypress vine climb and spread over them, which both shades and looks beautiful. Deciduous vines shade in summer and let light through in winter, which is a natural regulation. Trees can also be planted around the orchid garden, selecting evergreen trees, deciduous trees, bamboo, etc. of different heights to plant in combination, to regulate light intensity.

(2) Shade net shading. The shade shed can be built with bamboo, wood, angle steel, etc. as a frame, covered with bamboo blinds, plastic film, shade net, etc. On it, set a double layer of shade net with a 50%-70% shading rate; the upper layer is relatively fixed and only rolled up in winter, while the lower layer can be put down or rolled up. Use double layers in midsummer and a single layer in spring and autumn; use double layers at noon on clear summer and autumn days and a single layer on cloudy and rainy days. In winter, it depends on the situation: on clear days lower the lower layer, on cloudy days roll up the lower layer. In addition, before orchid flower buds are about to open, there must be moderate scattered sunlight, otherwise the flower color will be dim and not show its beauty. It is best to install the shade net as a movable type, so that the shading density can be increased or decreased as needed. The shade net should as much as possible not be pressed tightly against the plastic film or glass on the shed roof, and there should also be a gap of about 30 cm between net layers. The shade net should be set outside the plastic film or glass, so that the shading effect is good. If set inside the shed, its shading effect is greatly reduced. When growing orchids on a balcony, at noon when direct sunlight is strong, and because walls have reflected light and radiant heat, and ventilation is poorer than in a courtyard or orchid yard, in high-temperature seasons a 50% shade net should be hung outside the security grille for 3-4 hours around noon, to prevent scorching orchid grass; when the sunlight slants and the temperature has also dropped, it should be rolled up promptly to facilitate ventilation. Orchid shading requires a certain regularity. Generally speaking: large-leaf types more than small-leaf types, low-altitude types more than high-altitude types. In summer, more shading is needed, in winter less shading; at noon more shading, in the morning and evening less shading; at high temperatures more shading, when cool less shading, etc.

Second, "supplemental light." Regulating light in orchid-growing sites is not only about shading; when natural light is insufficient, artificial light must also be added to appropriately supplement light for orchid grass. This is especially so for indoor orchid growing and after the start of winter when light duration is short, which has a certain impact on orchid growth. Only by supplementing light to meet the orchid's light requirements can the orchid plant develop soundly, with solid stems, and grow and bloom.

(1) Basis for supplemental light. How to supplement light appropriately, and what kind of light to supplement? There must be a scientific basis. Sunlight is a collection of continuous wavebands of light from red to violet, and artificial simulation of the plant's growth environment should also start from this. In addition to considering the light quality and light intensity necessary for orchid growth, artificial supplemental light also needs to consider the physiological radiation characteristics of the light source. (Light waves matching the characteristic curve of plant chlorophyll synthesis are called physiological radiation light sources, that is, photosynthetic light waves.) Under different light qualities, not only does photosynthetic intensity differ, but the photosynthetic products are also not entirely the same. For example: plants absorb red light most strongly, followed by blue light. When plants grow under blue-violet light, the amount of protein and fat in their photosynthetic products increases, and it is effective for thickening stems and leaves, accelerating plant development, and regulating stomatal opening. Under red light, more carbohydrates are formed, which can promote orchid growth. Violet light and ultraviolet light mainly form anthocyanins and inhibit the elongation of branches and leaves (ultraviolet light must not be too strong, as it will scorch orchid leaves). Green light also cannot be ignored; it can promote oxygen production, thereby helping orchids better store nutrients. In addition, a certain intensity of long-wave ultraviolet light is also indispensable; it helps form anthocyanins and inhibit the elongation of branches and leaves. Supplemental light must be based on the effects of the above spectra and the growth condition of orchids in choosing a suitable light source.

(2) Light source selection. Because light quality has an obvious influence on the composition of photosynthetic products, people should choose a suitable light source according to the type of photosynthetic products needed. Ordinary incandescent lamps have less blue-violet light than the sun but more infrared light; fluorescent lamps have more blue-violet and green light but less red light. Generally speaking, orchid cultivation can use a mixed light of red, blue and white tubes to supplement insufficient light. A complete combination of red and blue spectra can enable orchids to achieve optimal growth. Philips' tri-phosphor 6400K fluorescent lamp can basically meet the growth requirements of orchids, and the price is cheap. Of course, if conditions permit, it is best to choose plant lights specially designed for orchid supplemental lighting; they are a bit more expensive, but the effect is better. Using LED lighting, the plant growth rate and photosynthetic rate both increase by more than 20%; compared with ordinary lamps, LED lamps have especially strong durability and save electricity, reducing operating costs. When choosing a light source, one should consider not only light quality and light quantity, but also low power consumption, economy, durability and convenience of use.

(3) Supplemental light duration. After installing artificial lighting equipment in the orchid room, the supplemental light duration should be determined according to the actual light conditions of the orchid-growing site, seasonal light changes, weather changes and the orchid's growth stage. The supplemental light duration also differs according to the orchid's different growth stages and the orchid-growing environment. Indoor orchid growing with weak light but able to receive scattered sunlight should have no less than 5 hours of supplemental light; balconies should have no less than 4 hours of artificial supplemental light; basements and indoor spaces without sunlight should have no less than 10 hours of artificial supplemental light. During the orchid's growing period, supplemental light duration should be longer, and during the dormant period it should be a little less; on cloudy, rainy and foggy days there should be no less than about 10 hours of artificial supplemental light. Supplemental light duration involves many factors and needs to be tested in practice to obtain a relatively correct supplemental light duration.

(4) Light distance. Light intensity is inversely proportional to the distance from the light source to the leaf surface, that is, the closer the distance, the stronger the light, so the height and distance of the light tube can be adjusted to regulate light intensity, to adapt to the appropriate light requirements of different orchid species. How to choose the light distance: the installation distance of the supplemental light lamp should be set according to the lamp power and the height of the orchids. The closer the lamp is to the orchids, the higher the light utilization, but care should be taken to avoid the lamp being too close to the orchids and the temperature being too high, which would cause harm to the orchids. Fluorescent lamps and plant-specific light sources (40W) should be at a distance of 20-40 cm; incandescent lamps (100W) should be installed at a certain height from the plants, because the large amount of infrared radiation from incandescent lamps converts into heat energy, so 70 cm or more is better; for high-pressure sodium lamps (120W-400W), maintaining a vertical distance of 1 m-1.5 m from the plants is more appropriate. For LED supplemental light sources, because LED produces very little heat energy, they can illuminate at close range, and 10 cm is better.

(5) Light direction. To ensure the supplemental light intensity for orchids, the lamps should as much as possible be arranged directly above the orchids. Benefits: first, because of plant phototropism, with more overhead light, the orchid leaves grown have stronger uprightness, meeting the aesthetic requirements of orchid lovers; second, if the angle of the light is consistent with the growth angle of the plant's stems and leaves, the light intensity received per unit area is higher, which is conducive to improving light energy utilization efficiency.

(6) Notes on supplemental light.

① It is best not to supplement light at night, because orchid growth requires a certain period of darkness to regulate the respiration function within the orchid plant and carry out the transformation and synthesis of dry matter within the plant.

② Pay attention to ventilation; most supplemental light lamps generate heat energy, especially in summer, which will raise the temperature of the orchid room or orchid shed and cause orchid diseases. Ventilation can reduce heat.

③ Comprehensive configuration of light sources. To obtain better supplemental light effects, light fixtures of different light sources need to be comprehensively configured, such as using a combined configuration of fluorescent lamps and incandescent lamps, or a combination of low-pressure sodium lamps and incandescent lamps. To meet the orchid's needs for various spectra during growth.

④ Pay attention to the installation safety of supplemental light fixtures to prevent accidents.

The above briefly describes the role of artificial supplemental light for orchids and some specific issues. In short, by appropriately supplementing light for orchids and ensuring that orchids have relatively sufficient light, it can not only improve the cold resistance of orchids when overwintering, but also ensure the vigorous growth and abundant flowering of orchids in the coming year.

Third, "hardening the grass." Orchids have a fairly strong adaptability to light, and this is also related to the generation count of the light intensity they receive. They will gradually change and adapt. For orchids that have always been grown in shade, if the light conditions are artificially changed, after a period of time the structure and function of their chloroplasts will undergo a certain degree of change to adapt to the new light conditions. For example, under weaker light conditions, the leaf structure and function of the plant will develop in a shade-tolerant direction, enabling them to maintain relatively high photosynthetic efficiency under weaker light; conversely, under stronger light conditions, the plant can also adapt to a certain extent and effectively use ample sunlight for photosynthesis. The folk term "hardening the grass" roughly means this as well - letting orchids adapt to different environments - including light, temperature, and so on. Through "hardening the grass," they can be strengthened generation by generation.

Fourth, display. In the display of potted orchids, according to the habits of each type of orchid, those with high light requirements should be placed where light most often reaches. Those with low light requirements should be placed in positions with less light. In addition, orchids have phototropism, so it is best to adjust the pot orientation once or twice a month to prevent the plant's leaves from leaning to one side. In particular, the side with new growths should face a direction with ample light during the budding period, so as to benefit sprouting and the healthy growth of the buds.

In summary, light plays a crucial role in the growth, development, flowering, and reproduction of orchid plants. Although orchids prefer shade, if all things in heaven and earth had no sunlight, they could not carry out photosynthesis to produce nutrients. Nor could they possibly survive. Therefore, light is the driving force of life for orchids. Photosynthesis is also a rather complex issue. The photosynthesis of orchids, like other biochemical processes, cannot exist in isolation, and at the same time is constrained and influenced by external environmental conditions. These external factors are: light intensity, concentrations of carbon dioxide and oxygen, wind speed, temperature, water supply, inorganic nutrients, and pollutants in the atmosphere and soil, and so on. At the same time, light is also affected by factors internal to the plant itself: for example, different orchid plants have certain differences in the duration, intensity, and requirements of light. Another example is the influence of chlorophyll content, the degree of stomatal opening, and the physiological state and structure of the leaves themselves. Only by improving the above internal and external factors can the goal of increasing the plant's photosynthetic efficiency be achieved. This promotes the healthy development, growth, and flowering of orchids.