How to grow orchids? A collection of cultivation experience (2)

　　III. Environment

Orchid cultivation is a systematic project, and the orchid-growing site is the foundation of that system, occupying a very important position. Most orchid enthusiasts adapt their growing site to local conditions, setting aside space on their own balconies and indoors to grow orchids. Compared with the places where orchids grow on mountain slopes, balcony and indoor growing sites generally lack ground energy and dew, have higher nighttime temperatures, and lower humidity. Because regions and locations differ, orchid-growing sites on balconies and indoors also differ from one another: some get more sun, some less sun, some have strong wind, some weak wind, and so on. Once an orchid-growing site is chosen, you must clearly understand the shortcomings of your own site. Only by facing those shortcomings squarely can you remedy and change them through orchid pots, potting media, management methods, and so on. The orchid-growing site must be kept clean.

Sunlight: All things grow by the sun. Although orchids are shade-loving plants, they also like sunlight. Sunlight supplies orchids with nutrients and also kills viruses and sterilizes, making it an important factor in strong plants. When conditions allow, expose them to as much sunlight as possible. Orchids grown under sufficient sunlight have shorter leaf shapes, thicker leaf texture, and yellowish leaf color, and are healthy and strong. The flowers they produce have thick, substantial petals, a fine, smooth texture, and vivid flower color. When a person feels hot or uncomfortable in the sun, it is time to provide shade.

Temperature: Temperature is an important factor affecting orchid growth. Orchids grow slowly at low temperatures; the lower the temperature, the slower the growth, until they enter dormancy. At temperatures suitable for orchid growth, orchids begin to grow; the higher the temperature, the more vigorous the growth. At high temperatures growth slows again; the higher the temperature, the slower the growth, until they enter dormancy. Orchids growing naturally or under cultivation are mostly in a slow-growth period, and spend less time in vigorous growth. The low-temperature period, the high-temperature period, and the suitable-temperature period are not fixed and unchanging; they vary with the characteristics and strength of the orchids. Orchids grow under constantly changing temperatures, and those constantly changing temperatures create a temperature difference. Temperature difference is an important factor affecting the strength of orchids. Orchid growth is related to temperature, and orchid consumption is likewise related to temperature; the higher the temperature, the greater the consumption. To make orchids strong, while increasing nutrient supply you must reduce orchid consumption. The simplest and most effective way is to lower the nighttime temperature and widen the temperature difference. Enclosed balconies and indoor spaces generally have higher nighttime temperatures, so during high temperatures special attention must be paid to lowering the nighttime temperature and widening the temperature difference. People's health-preserving ways stress keeping warm in spring and cool in autumn; in fact orchids are the same and also need keeping warm in spring and cool in autumn, so that orchids have a process of adapting to temperature changes and their resistance is strengthened. This is also the reason behind the saying that orchids should not be brought out in spring. The resistance of orchids to high temperatures and tolerance of low temperatures is related to the strength of the orchids and the temperature difference; the stronger the orchids, the better their resistance. The greater the temperature difference, the better the resistance shown by the orchids.

Humidity: Orchids can grow normally under different humidity environments, and their humidity requirements are also loose and flexible. Humidity changes with temperature and ventilation; high temperature and strong ventilation mean low humidity. Under natural conditions in the Jiangnan region, humidity can already meet the growth needs of orchids, so there is no need to spend much thought on humidity. One point to note: just do not have high temperature together with high humidity. If humidification is needed, it is best done at night, which both mimics nature and lowers the temperature, increasing the temperature difference.

Ventilation: The ancients paid great attention to ventilation and called it the first essential of orchid growing. Ventilation plays a role in orchid cultivation by regulating dryness and moisture, regulating temperature, and driving nutrient exchange. Ventilation is divided into ventilation inside the pot and ventilation of the environment. Ventilation inside the pot mainly depends on choosing good orchid pots and potting media; in management, the orchid pot must not remain constantly wet without drying. Environmental ventilation mainly makes use of natural wind, opening doors and windows as much as possible, setting up a temperature difference, letting air convect, and using fans, and so on. Strong winds and cold winds in natural wind should be avoided.

Placement: Within the same site, because positions differ, sunlight, temperature, humidity, ventilation, and so on also differ. You should choose suitable positions according to the characteristics of the orchids and the dry or damp condition of the orchid pots. In this way you both comply with the characteristics of the orchids and achieve uniformity in management. Once orchid pots are placed on shelves, they should not be frequently moved or turned. During high temperatures, the sun must not shine directly on the pot body.

Environment: Shady, humid, with gentle breeze. Orchid growing must have shade, either placed under tree shade or shaded with shade netting. How many layers of shade netting to use varies with orchid species, region, and season. Black shade netting absorbs heat; silver-colored netting is relatively better. In short, if a person feels comfortable in it, the orchids will feel comfortable too. Cymbidium ensifolium (jianlan) prefers more light, while Cymbidium sinense (molan) prefers more shade. General orchid books stress ventilation; I think it should be gentle breeze. Orchids dislike strong wind blowing directly, especially dry strong wind, otherwise it easily causes orchid leaves to dehydrate and form black spots. Orchids like air to move very slightly, with orchid leaves lightly brushed; some orchid enthusiasts even call it "air passage, not wind passage." Therefore, the shade netting around an orchid shed should reach the ground, and below about 1.5 m from the ground double-layer shade netting should be used; this filters strong wind on the one hand and maintains a certain air humidity on the other. Orchids like fresh, unpolluted air, so the orchid-growing site should be far from roads, cooking fumes, and dust. Orchid pots are best grown on shelves 40-60 cm high; too high and the air is dry, too low and there is no ventilation, so take a balance. The suitable air humidity for an orchid-growing environment is 50%-80%. Insufficient humidity is a hard problem for home balcony orchid growing. You can place water-absorbing materials on the ground, such as red bricks, sponges, and so on, and regularly sprinkle water on the ground. You can also add a water trough, but the water in the trough must be changed frequently, otherwise it will breed bacteria and mosquitoes. Around it, plant some flowers and trees with strong transpiration, such as Pachira aquatica (money tree), Epipremnum aureum (pothos), Dypsis lutescens (areca palm), and so on. Do not spray water on orchid leaves, especially on sunny days with high temperatures; doing so will undoubtedly provide a hotbed for pathogens and pests, and you will pay the price.

Resolving the contradiction between ventilation and humidity: Ventilation and humidity means spatial ventilation and spatial humidity, and air permeability inside the pot and potting-medium humidity. These are two issues of the macro-environment and the micro-environment. How to handle these two issues of macro-environment and micro-environment properly is exactly the interest and key of orchid growing, and exactly the mystery of orchid growing! Between ventilation and humidity, which is more important? Both are important, and the two cannot be separated. But if humidity is at 80-90, ventilation becomes extremely important. If humidity is at 40-50 or below 40, humidification is extremely important. So-called ventilation does not mean strong wind, but air permeability, that is, the potting medium in the pot must be air-permeable, the indoor space must have a gentle breeze, fresh air must be exchanged frequently, and the air must not be stuffy. "Ventilation should come first": more precisely, when humidity reaches 60-80, the question of ventilation first can be considered; if it is below 50, humidification should be considered. Of course, various orchid types also have different humidity requirements. For example, Cymbidium faberi (huilan) can have relatively lower humidity, around 50, while Cymbidium sinense (molan) needs higher humidity, which should be around 80. Of course, pot types and potting media can also differ accordingly. For example, Cymbidium faberi can use clay pots and sweating pots because they are air-permeable, while Cymbidium sinense can use plastic pots and purple clay pots because they retain moisture. When dealing with problems and contradictions, one must absolutely not be bookish or dogmatic; one must consider things comprehensively and must not emphasize only one aspect. Whether ventilation, humidity, fertilizing, pesticide use, light, or pot type and potting medium, all should be considered comprehensively. As long as the cultivation environment can be made "secluded," that is the best.

Enclosed balconies in the high-temperature season. Ventilation should be moderate; natural ventilation is best. High temperature and stuffy heat are a great enemy of orchid growing. Therefore, ventilation is very important for orchid growing on enclosed balconies in the high-temperature season. Enclosed balconies generally have sliding aluminum-alloy glass windows that can be freely opened and closed, and the degree to which the sliding windows are opened can be used to control convection and form natural ventilation. In summer, with bright sun and oppressive heat, the sliding windows should not be opened too wide during the day; generally about 20 cm is appropriate. In this way, the temperature difference between the balcony and outside the window can be used to form natural convection, with a gentle breeze brushing and orchid leaves swaying, just right. If the windows are opened too wide, the temperature difference becomes too small to form convection, and instead ventilation becomes poor. Practice has proved that enclosed balconies can fully use opened sliding windows to form natural convection; generally there is no need to use electric fans, and natural ventilation is still better. Humidity should be moderate; avoid excessive wetness or dryness. In summer evaporation is fast, and on clear days air humidity is low, which is the bottleneck restricting balcony orchid growing, so efforts must be made to create a micro-environment suitable for orchid growth. According to my experience, using a water trough to humidify in summer is a good way to raise air humidity. The water trough is best set up together with the orchid shelf; each layer of the orchid shelf should have a water trough. The trough depth is generally best at 20-30 cm; fill it with water and cover it with steel wire mesh, with the orchid pots sitting on top. This both increases air humidity and has a certain cooling effect, achieving two things at once. Combined with sprinkling water on the ground, the balcony humidity during the day can reach about 40%, which can basically meet the humidity requirements of orchids. Humidity is not better the higher it is; especially in summer, excessive humidity is the source of a hundred diseases in orchids, and orchid enthusiasts should take warning.

Avoiding warm, humid airflow belts in the micro-environment. In balcony-type small orchid rooms, because the area is small and there is only one wind direction, no warm, humid airflow phenomenon appears. Now, however, sunlight rooms have a larger area and use wall-mounted fans. The formation of warm, humid airflow belts in the micro-environment is caused by unscientific configuration of our air-supply system. Once wind channels from several different directions intersect and form an unreasonable situation, warm, humid airflow belts are created. Each time after we flush orchids with a heavy watering, we turn on the fans thinking the water accumulated in orchid buds will dry quickly, but in fact it is not so. For orchids growing within warm, humid airflow belts, because of the characteristics of physical water-vapor movement, the accumulated water in the buds is hard to dry; when the moisture content is slight, we generally cannot easily detect it with the naked eye, and at this time it creates the best hotbed for harmful bacteria to multiply, ultimately causing frequent disease in that zone. I visited many orchid enthusiasts in Zhejiang and saw the configurations in their orchid rooms. Leaving aside the use of integrated control systems for now, their wind-system configurations truly have something unique. For example, two exhaust fans are installed in the middle of the orchid shelf at the height of the orchid leaves, arranged in a row 3-5 m apart; from a distance they form rows and columns facing the same direction, sending a gentle breeze. At the same time, with the suction and exhaust cooperation of the intake and exhaust fans set into the walls at both ends, the orchids in the orchid room are always kept in fresh air, so it is no wonder the flowers and leaves flourish and grow strong. Scheduled intake and exhaust of air is needed to ensure orchids exchange fresh air and to promote reasonable transpiration and metabolism, making orchids grow lush and verdant. This is undoubtedly an excellent design. So fan placement is not better the more there is; rather, it should follow one direction.

　　IV. Watering

How to water correctly

Veteran orchid growers say: "Watering takes three years." That is to say, to water orchids correctly you must spend three years before you can master the knack. Why is watering so difficult? The main reasons are that climate changes differ each year, orchid garden environments differ (on the mountain, at the foot of the mountain, or in a greenhouse, on a balcony, and whether there is humidification………. and so on), placement locations differ (in the same orchid garden every place has different light and ventilation, affecting how long each pot of orchids takes to dry), pot sizes differ (large pots dry slowly, small pots dry quickly, so watering times differ), potting materials differ (different potting materials have different water absorption rates, so watering methods differ; for example, with large-grain Ishiyama stone cultivation, you may need to water once every ten minutes, five seconds each time, continuously back and forth five times, before the pot is wet enough, while other mixed materials may be wet enough after two waterings), orchid plant condition (healthy large clumps are more drought-tolerant and can be watered after they are drier; old heads, small seedlings, or single plants have imperfect root systems and must be watered when they are about to dry), and orchid species (you can look at the orchid roots: the thicker and larger they are, the more drought-tolerant, and they can be watered after drying a bit; fine, long roots are not drought-tolerant, and they must be watered as soon as they dry), and so on. All of these affect watering times differently. So there is no fixed, unchanging method for watering; it relies on the accumulation of personal experience. But there are still some unchanging principles as follows:

(1) Do not water unless dry: Orchid roots are fat and thick and store a considerable amount of water, so they are basically quite drought-tolerant. Therefore, watering should be "clearly dry and clearly wet," that is, when dry it should be very dry, and when watering it should be watered very wet. The worst thing is half wet and half dry, or wet for a long time without drying. Orchid roots are somewhat like a balloon: inflate it fully and then let the air out, and it can be inflated many times without fear; but if it is inflated fully and the air is not let out, after a week it loses elasticity, and the balloon loses its original function. That is why orchids rot roots; most cases are caused by being too wet and by poor ventilation in the pot. So if the surface material in the pot is not dry and the leaves are not slightly drooping, then there is no need to water.

(2) "Cool": When watering, choose cool weather with a temperature of 28°-20° and a bit of wind. In summer 28° may be after ten p.m., while in winter 20° becomes noon at twelve (the lower the temperature, the warmer the time for watering), so when there is sunlight, any time at 22° or below can be used for watering (at low temperatures choose a time with sunlight for watering, and orchid roots grow better); above 22°, choose cloudy days, dusk, or night for watering (the higher the temperature, the later the watering).

(3) Ideal watering times: 1. On sunny days, or when the shed temperature is above 23 °C, it is best to water from 7 to 9 p.m.; that is, the higher the temperature, the later the watering. 2. On cold days, or when the shed temperature is below 18 °C, it is best to water between 11 a.m. and 3 p.m.; but on rainy and cloudy days, sometimes the temperature is also above 25 °C, so pay attention; that is, the lower the temperature, the earlier the watering. But note that if sunlight is strong and the temperature is low, you can water with confidence, because the quality of orchid roots is related to temperature and sunshine.

(4) Learn from nature: When orchids need water and when they do not mainly depends on whether the orchids are sprouting; if they are, then the growth period has arrived. We see that in the plum rain season it rains for a whole month, plants absorb a large amount of water, and so they grow rapidly. As for summer and winter, excessive heat and severe cold are not suitable for orchid growth, and these are dormant periods. Therefore, when the orchid pot is dry, water it. In summer, because the climate is severely hot and water evaporates quickly, water as soon as it is dry, otherwise the orchids will dehydrate and die. In winter, when the temperature is low, if there is no sunlight or wind, even if you do not water for a month, the orchids will not be affected. So at low temperatures with no sunlight, frequent watering easily causes orchid root rot. As for autumn, it is the period when orchids set heads and prepare to bloom, so a slightly drier watering method should be adopted, that is, water after the orchid pot has been dry for one or two days. Therefore, the control of watering mainly depends on whether the orchids are in the growth period, the head-setting and flowering period, or the dormant period, to decide the dryness and moisture of the orchid pot. So you should learn from nature and consult the farmers' almanac to decide how to water orchids. (If the material in the pot is too fine, then it must not be rained on, otherwise roots will rot.)