How to grow potted cold orchids? Cold orchid cultivation methods
The cold orchid (Cymbidium kanran) is a plant of the genus Cymbidium in the orchid family. It has a slender, well-proportioned plant shape, elegant and graceful leaves, bright and varied flower colors, and a pure, long-lasting fragrance. It is an excellent choice for making floral bonsai. A pot of cold orchid bonsai full of vitality and mystery placed at home will add much charm to the home. Cold orchid bonsai are very popular on the market. The cold orchid bonsai at Yiyuan Flowers and Bonsai have well-proportioned flowers, bright and vivid colors, and flat shoulders, and can be called the beauty among flowers. At the same time, many people are still troubled by how to care for the "cold orchid bonsai," the beauty in their home.
To grow cold orchids well, you must first understand their habits and study their characteristics. According to the author's observations and records of collecting orchids in recent years, wild cold orchids generally grow in mountain forests at an altitude of 650—1200 m. Places where cold orchids grow generally have relatively dense trees and are often accompanied by capsule-bearing plants. Therefore, the degree of shade is relatively high. Cold orchids prefer to grow in southeast-facing mountain forests with relatively steep slopes, loose soil, rich humus content, good drainage, fresh air, and relatively high humidity. Cold orchids generally have longer, slightly thin leaves, and most pseudobulbs are relatively small (but the natural hybrids of cold orchid with black orchid or four-season orchid have larger pseudobulbs), with well-developed root systems, and they bloom very easily with tall scapes and many flowers.
Among the above characteristics, long and thin leaves indicate a need for humidity (air humidity) and fear of sun exposure. Small pseudobulbs and well-developed roots indicate little stored nutrients, requiring timely absorption and supplementation by roots and leaves. Blooming many flowers indicates high nutrient consumption, so they like fertilizer. In response to the above situations, various comparative experiments have also been done. The author believes that the following 7 aspects should be noted when cultivating cold orchids.
1. Carefully choose the growing medium
Soilless cultivation is currently popular, and hard growing media are used for growing all kinds of orchids. The author has done comparative experiments on various growing medium formulas and found that no matter which growing medium is used, cold orchids grown with some mountain soil (humus soil) mixed in grow best. This may be because artificial means still cannot supplement and satisfy the nutrients needed for cold orchid growth. The following growing medium formula, proven by experiments to be more suitable for cultivating cold orchids, is now recommended: pond foundation stone or planting gold stone (coarse river sand or other hard growing media may also be used instead) 40%, mountain soil 35%, spent mushroom substrate or sawdust from cultivated edible fungi 15%, and snake wood 10%.
2. Provide appropriate and reasonable shading
As mentioned earlier, cold orchid leaves are slightly thin, so overly strong sunlight easily damages the leaves. In some orchid enthusiasts' cold orchids, if the upper surface of the leaves is yellowish brown or dark brown while the lower surface is still green, that is mild sunscald. When sunlight is too strong, phenomena such as scorched leaf tips, yellowing leaves, and premature aging easily occur. In addition to affecting the normal growth and lifespan of the orchid, the ornamental value is also greatly reduced. According to the author's practice, using one layer of 65—75% shade netting in winter and spring and another layer of 50—60% on sunny days in summer and autumn is most suitable for growing cold orchids (shading may be omitted on cloudy and rainy days). In short, under the premise of not scorching orchid leaves, appropriately seeing more sunlight is beneficial to both orchid growth and flowering. Never leave them indoors for a long time or shade them excessively for fear of sun damage.
3. Strictly control watering
This is the key to growing cold orchids well (other orchids are similar). It is also one of the reasons many beginners fail at growing orchids. Too much water will inevitably rot the roots. For the cold orchids the author has grown, whether in large pots or small pots, generally water once every 8—15 days in spring, once every 4—7 days in summer, once every 5—10 days in autumn, and often do not water for more than 20 days or even over a month in winter. To facilitate relatively uniform management of large and small pots, I reasonably match pots according to the number of seedlings and the degree of root development, that is, plant more seedlings in large pots and fewer seedlings in small pots. Use large pots for well-developed root systems and small pots for poor root systems. Strong seedlings can also be used to accompany weak seedlings, and rare famous varieties can be grown together with ordinary varieties. In this way, the watering cycle for large and small pots can basically be the same. The principle for the potting soil is to water when dry and let it dry somewhat between waterings, water thoroughly when watering, and keep it slightly dry at ordinary times. Cold orchids grown this way have well-developed root systems and grow robustly, and root rot or premature root decline rarely occurs.
4. Maintain air humidity
According to the cold orchid's habit of liking high air humidity, it is advisable to artificially create a relative humidity of 40--70% during the day and no less than 80% at night. Measures such as humidifiers, sprinkling water on the ground, and setting up water pools or water basins to increase humidity can be used. When air humidity is high, cold orchid leaves are glossy and emerald green, grow well, and are easy to grow into top-grade seedlings with fully intact leaf tips, but remember to maintain ventilation.
5. Fertilize with a scientific combination
Because cold orchids have relatively small pseudobulbs, the nutrients they store are limited. In addition, they bloom easily and have tall scapes, many flowers, and large flowers. They consume more nutrients, so when cultivating mature plants and strong seedlings of cold orchids, it is best to add a small amount of base fertilizer when repotting. The author's experiments found that mixing about 1% fully decomposed, fermented, and sterilized pig manure into the growing medium is most beneficial to cold orchid growth. However, newly collected orchids just brought down from the mountains, newly purchased orchids transported long distances or sent by mail, and weak seedlings with imperfect root systems must not be fertilized in a hurry, otherwise they will inevitably suffer fertilizer damage. In addition, potassium dihydrogen phosphate, orchid fungus king, and the like can be used alternately for foliar fertilization, once every seven to ten days. During the new bud growth period, an appropriate amount of urea may also be added, and during the new seedling maturation period, spray two to three times with high-potassium fertilizer to promote pseudobulb enlargement. To make various nutrients more balanced, from April—June and September—October, a thin organic fertilizer may be applied once a month, such as decomposed cake water or fishy water. Pay special attention that fertilization must be strictly in accordance with the proportion; it is better to be dilute than concentrated, otherwise it will cause fertilizer damage and bring regret too late.
6. Strictly prevent harmful pollution
Like other plants of the same genus, cold orchids like a fresh, pollution-free growing environment. When building an orchid garden, try to avoid nearby workshops and factories that discharge thick smoke and waste gas and produce large amounts of dust. For home cultivation, keep as far away as possible from chimneys, range hoods, and the outdoor air outlets of air conditioners. At the same time, choose clean water with no pollution and moderate pH. In other words, any environment where people feel the air is fresh, with no smoke, little dust, no peculiar smell, and good ventilation is suitable for growing orchids. Any water that people can drink can be used to water orchids. In addition, try not to smoke in the orchid room.
7. Prevent pests and diseases in time
Doing a good job of orchid garden sanitation and thoroughly eliminating pests, disease sources, and sources of infection is the key to pest and disease prevention and control. Second, cold orchids are suitable for pot cultivation on benches, which makes them easier to manage than ground cultivation, with less pollution and fewer pests and diseases. Third, spray pesticides at the right time. Generally, March—April in spring and October—November in autumn are the key periods for pest and disease prevention and control. During these periods, spray disease-prevention and insect-killing pesticides once every 10 days to half a month; at other times, once a month or twice a season is enough. For disease prevention, fungicides such as thiophanate-methyl, carbendazim, copper hydroxide, and dimethomorph can be selected, and for pest control, omethoate, profenofos, jieshijing, and deltamethrin can be used. These are introduced in many orchid books, so I will not repeat them here.
Warm tips:
Whether cold orchids can bloom, bloom well, and give off a delicate fragrance depends greatly on care. For dark-colored flowers, light should be somewhat stronger, and for plain-centered ones, somewhat shadier. From when the flower scape begins to elongate until before flowering, if plant protection is neglected, the flower buds easily become and rot. For this reason, cold orchid flower buds are easily infested by mites. This pest's color is similar to that of the flower buds, and once discovered too late for control, the flowers will not open. Therefore, spraying drugs such as Flower Health No. 1 and fenpropathrin can effectively prevent and control it. To make the fragrance of cold orchids purer, they should be exposed to more sunlight during the flowering period, so that even at night, a delicate fragrance will drift about.