Detailed Explanation of Wild Jianlan (Cymbidium ensifolium) Prices and Fertilization Methods

Jianlan is a subtropical terrestrial orchid, mainly produced in the provinces and cities south of the Yangtze River. It originates in forest edges along streams, bamboo groves, and hillsides overgrown with shrubs and thatch grass, at an average annual temperature of 17-21°C, annual rainfall above 1600 mm, altitude of 350-1000 m, and canopy density of 50%-60%. The characteristics of these places are: above there are tall tree crowns or clumps of shrubs. Thatch grass serves as a natural barrier, and the ground surface is covered with a layer of fallen branches and leaves, forming a warm, humid, ventilated, shady, and fertile ecological environment.

　　

During our survey in the Wuyi Mountains, we once took samples for analysis. The soil nutrient content was: pH 4.4-5, ammonia 0.75%, phosphorus 0.38%, potassium 0.4%, organic matter 16.7%. Humus content in the organic matter accounted for 50%-90%, and the main component of humus was humic acid, which is the main cementing agent for forming soil aggregate structure. This aggregate structure plays a great role in fertility. It can increase the soil's water-holding capacity and can absorb water 4-6 times its own weight (when this kind of mountain soil is used for growing orchids in an orchid nursery, even in the hot summer season, generally only 1-2 waterings per week are needed). In addition, when the humus content in the soil is high, the soil color becomes darker, which can improve the heat absorption and warmth retention capacity of the potting soil. The higher the organic matter content, the looser the soil, and the better it can coordinate the contradiction between soil moisture and air, and the easier it is for orchid symbiotic fungi.

　　

Orchid fleshy roots are thick and fleshy, have no root hairs, and cannot directly absorb nutrients from the soil. During the growth process, because the conditions for orchids and fungi to grow together are suitable, orchids grow abundantly with luxuriant flowers and leaves year after year. The fungi that supply nutrients to orchids mostly belong to a species of the genus Rhizoctonia among the Fungi Imperfecti, and some people also call it "orchid fungus." The so-called Fungi Imperfecti are filamentous fungi whose sexual generation is not yet known, and they are widely distributed in forest areas from temperate to tropical zones. The hyphae of Rhizoctonia widely live in the soil. Its secondary hyphae form root-like rhizomorphs, cross the soil layer, search for hosts, and once they encounter orchid fleshy roots and pseudobulbs, they tightly attach and penetrate into the inner cells, growing hyphal branches. The protoplasm in the infected cells is first decomposed and utilized by the hyphae. At the same time, the Rhizoctonia hyphae gradually thicken and form hyphal pellets. Afterward, the cell nuclei undergo aberration and nuclear decomposition, and most of the formed hyphal pellets are swallowed and digested by the lysozyme produced by the cells that contain them as soon as they are just formed. Through this intracellular digestion, the protoplasm becomes very dense, the cell volume also increases, and irregular aberration occurs. After a period of time, the cells restore their original state and again digest newly invading hyphae. With the continuous invasion and digestion of hyphae, as well as the periodic changes of digestive cells, orchids obtain a large amount of nutrients continuously from the roots and pseudobulbs (the nutrition needed for orchid growth, development, flowering, and fruiting is satisfied).

　　

According to observations, humus in the soil has the greatest effect on mycorrhiza formation, while cellulose and lignin have very little effect. Therefore, to make potted orchids grow vigorously and bloom every year, when preparing orchid culture soil, mountain soil with high humus content should be selected. Nowadays, peat, sawdust, crushed brick and tile pieces, expanded stone, vermiculite, perlite, sphagnum moss, and other materials are also used for planting, and potting substrates are artificially created. The porous air chambers in the planting material that are ventilated and water-permeable allow air to pass through smoothly, and the oxygen needed for orchid growth is satisfied through the pores of these substrates. Orchid culture soil with porosity greater than 65% is not only soft, with good air permeability and water retention, but also has relatively good fertilizer retention. If other substrates are selected to replace mountain soil for growing orchids, then artificially prepared nutrient solution needs to be applied. When these porous substrates are used to plant orchids, their roots are white and strong, will not produce black boards due to oxygen deficiency and suffocation, and will not rot due to lack of water or water accumulation, which is very beneficial to the vigorous activity of orchids and their symbiotic fungi.

　　

Orchids are evergreen plants that like fertilizer. In a suitable temperature environment, they grow almost all year round, so they consume a large amount of fertilizer. During the cultivation of potted orchids, nitrogen, phosphorus, potassium, as well as calcium, magnesium, iron, copper, manganese, zinc, and molybdenum elements must often be supplemented into the potting soil. We once conducted the following experiment: from May to August, when orchid leaf buds began to emerge, healthy and robust orchids with normal growth were selected and divided into 5 groups, with 10 pots in each group; groups 1-4 were respectively given block-shaped peanut meal 5 g, 10 g, 15 g, 20 g, and another group was the control group, applied twice a month, 10 times in total. The result was that the more fertilizer, the faster the growth speed of new orchids and the greater the number of new shoots sprouting. A liquid fertilizer experiment was conducted: (ammonia concentrations of 28.5X10ˉ6, 56X10ˉ6, 125X10ˉ6, 230X10ˉ6). The result was also that the higher the concentration, the better the growth and development. However, for orchids with declining growth or severe disease, as well as newly collected wild orchids, it is not suitable to fertilize, otherwise, the higher the concentration and the more times of application, the higher the shrinkage and mortality rate of orchids. These diseased orchids are often in a semi-dehydrated state. To promote their recovery and rooting, it is best to frequently regulate them by foliar fertilization, spraying weekly with 1000-fold potassium dihydrogen phosphate solution plus 250-fold rice vinegar, or adding 100-200 micrograms of B12 one vial (urea 20 g) to every 12.5 kg of water-fertilizer solution, and after new shoots grow to 5-10 cm, then apply thin fertilizer as appropriate to promote growth, and carry out normal maintenance and management.

　　

Orchids continuously absorb various nutrients throughout their entire growth process. To fully supply these nutrients in a timely and appropriate amount, rational fertilization is needed. When nitrogen is supplied sufficiently, orchids grow luxuriantly and remain normally green. When nitrogen is deficient, leaves fade green and turn yellow, the plant becomes short, and growth is inhibited. But things should be viewed in two. When nitrogen is excessive, the vegetative organs of orchids grow excessively, the plant leaves become soft and spindly, and new leaves often surpass old leaves, making them highly susceptible to disease, and reproductive genes are inhibited, affecting flower bud differentiation and flowering. Modern household balcony area is limited, and the appreciation of orchid leaves also requires control, width, and uprightness. To make orchid plants grow robustly, it is also necessary to increase the application of phosphorus and potassium fertilizers. Phosphorus can promote cell division and proliferation in orchid plants and the synthesis, transformation, and transport of organic matter, improve drought resistance, cold resistance, and disease resistance, and promote root system development and flower bud differentiation. Potassium can increase the intensity of photosynthesis, promote the transformation and transport of carbohydrates, increase the content of fibrous tissue in leaves, make orchid leaves tough and upright, and improve stress resistance. After increasing the application of heavy potassium in the later growth stage of orchids, it can also make pseudobulbs plump and the plant dwarfed. Therefore, in the early stage of orchid vegetative growth, fertilization is best with nitrogen, phosphorus, and potassium applied equally (2:2:1). When entering the leaf expansion stage, it should shift to mainly phosphorus and potassium (1:4:3). In the later stage, heavy potassium can also be applied, which can make the plant short and strong.

　　

Temperature can both promote the decomposition of soil organic nutrients and promote the metabolism of orchids and fungi, enhancing nutrient absorption capacity. The temperature differs across the four seasons, so the amount of fertilization should vary. Spring and summer are the vigorous growth periods of orchids, so the frequency and amount of fertilization can be appropriately increased. In winter, when the temperature is low, growth is inhibited; if the temperature is below 15°C, then stop fertilizing. In short, the amount and frequency of fertilization throughout the year depend on temperature. If the suitable temperature for orchids of 20-30°C can be maintained, fertilization can continue throughout the year. This can promote their vegetative growth, and orchids can sprout twice a year and grow robustly.