A detailed explanation of orchid growth habits, a comprehensive understanding of the growth characteristics of orchids

    I. Requirements for the growing medium

Wild orchids grow on shady, well-ventilated mountain slopes where water does not accumulate, so the growing medium is required to be: air-permeable, loose and soft, with good drainage, and slightly acidic. The most commonly used medium for outdoor cultivation is mud flower soil.

Orchid soil refers to the soil that accumulates in the crevices of rocks on mountains, formed from plant leaves through wind, rain, and sun until they rot; the soil is loose and soft, air-permeable, and slightly acidic. In the Jiangnan region of China, it is customary to dig orchid soil in places such as Kuaiji Mountain in Shaoxing, Yanwo Ridge in Yuyao, Shiniu Mountain in Fuyang, Baoshan in Hangzhou, Tongguan Mountain in Yixing, Junshan in Nantong, and Yushan in Changshu. Before liberation there was a saying, "one load of flower soil for one load of rice."

Weathered mountain rock gravel soil can also be used as a growing medium. Farmers in Cangyan Town, Shengzhou, use the gravel soil of the local Cangyan Mountain as a growing medium; "Cangyan Su" has been cultivated with this soil for more than a hundred years. Recently, some people have also used red soil brick gravel and red soil mountain mud as a growing base, and some have used soil with clumps of weeds that has been roasted over a fire into crushed roasted soil as a medium. Both of the above conform to the characteristics of being air-permeable, water-permeable, and slightly acidic, and are rich in phosphorus and potassium fertilizer, so they can be used as an orchid growing medium, but nitrogen fertilizer must be supplemented appropriately. In recent years, with the introduction of orchid growing from Hong Kong, China, Taiwan, China, and abroad, indoor orchid growing has been greatly promoted, so the use of sphagnum moss, perlite, volcanic ejecta, granular bricks, granular Xiantu, granular peat, and the like has become an ideal medium. Their greatest advantage is that they make water management easy.

　　

II. Requirements for temperature and humidity

The optimal growth temperature for Jiangsu and Zhejiang orchids is 18--30 degrees Celsius; below 5 degrees Celsius and above 35 degrees Celsius they grow slowly, and the reproductive growth period is 5--18 degrees Celsius.

Orchids grow well when the relative air humidity is 60--70%; too dry or too wet can easily trigger orchid diseases. Therefore, outdoor cultivation must create a gradual humidity microclimate suitable for orchid growth, and indoors, sprayers and hygrometers should be installed.

　　

III. Requirements for sunlight exposure

Wild orchids grow beneath dense forests and tall bamboo, where the jungle blocks intense sunlight. This makes orchids prefer shade and fear the sun. Sunlight is essential for plant photosynthesis and is the energy source for producing nutrients. Orchids like morning sunlight. When the morning sun first rises, the sunlight angle is low, and the area of the orchid receiving light is large. Also, because the morning sunlight is blocked by morning mist, the light is relatively soft, and direct exposure will not scorch orchid leaves. After nighttime nutrient accumulation, orchids have their strongest photosynthetic capacity in the morning. Therefore, in summer, sunlight can be allowed to shine directly on orchid leaves before seven o'clock, and after seven o'clock a 50%--90% shade net should be used to block the sunlight. Around "Qingming," orchids can be given more sun to promote root development and produce more leaf buds; after "Bailu," when the weather turns cooler and most new plants have grown, they can also be given more sunlight to promote full flower buds and allow the orchid plants to store more nutrients for the next year's growth. The length of sunlight exposure directly affects orchid growth. With more sunlight exposure, orchid leaves are more yellow, orchid roots are more developed, and flowers are healthier. Conversely, orchid leaves are dark green, the root system is not well developed, and it is not easy to produce flowers. Petals of flowers exposed to sunlight for a long time are thick in texture; conversely, the petals are thin in texture. But if exposed to sunlight excessively, orchid leaves may be scorched, and even cause dehydration and death.

　　

IV. Requirements for water

Controlling water is the most fundamental condition for growing orchids well. Orchid leaves are relatively thick in texture, with a cuticle on the surface for protection, so orchid leaves do not consume large amounts of water. The pseudobulbs and fleshy roots of orchids can store a certain amount of nutrients and water, so they are relatively drought-tolerant. Except during the root-growing and sprouting stages and the rapid growth period, when more water is needed, at other times they consume less water. If there is too much water, causing water to accumulate in the soil and blocking root respiration, root rot easily occurs. Too much water can also cause orchid leaf cell walls to become filled with water, opening the stomata on the leaf surface, resulting in diluted nutrient content, and further causing weak tissues, poor growth, and disease. Orchids "like rain but fear waterlogging, like moisture but fear wetness." Because air humidity differs in spring, summer, autumn, and winter, orchid growth rates differ, and water requirements also differ. Accordingly, there is a saying that "whether you can grow orchids mainly depends on whether you can water them."

　　

V. Requirements for air

Orchids like circulating, unpolluted air. The orchid-growing site should be far from coal gas and oil fumes, and far from places with flying dust. Oil fumes and dust attached to the leaf surface will block leaf respiration and affect photosynthesis. When air does not circulate, bacteria and viruses will attach to the leaf surface, harming orchid growth.

　　

VI. Requirements for fertilizer

Orchids like mildness; when fertilizing, it is better to under-fertilize than to over-fertilize. Like other plants, nitrogen can promote lush growth of stems and leaves. Phosphorus can promote well-developed orchid roots, promote robust development of reproductive organs, and spread of stems and leaves. Magnesium, sulfur, iron, and other trace elements can make leaves green and flowers strong.

During the vigorous growth period of orchids, more fertilizer should be applied; during the dormant period or weak growth period, fertilizer may not be applied. If fertilizer is applied excessively, it will burn roots and leaves, causing irreparable losses.