How to correctly prepare orchid potting soil

OrchidsMethods for making potting soil PlantingOrchidsneed specially made potting soil, also known asorchidmud. Orchid pottingsoil should preferably be loose and breathable, well aerated, with an appropriate amount of fertilizer, and free ofpests and diseasesin hiding. The composition of potting soil is made from one or several basic ingredients (substrates). These basic ingredients include soil, fertilizer, and other materials, and there are quite many types. Some ingredients may seem unrelated to soil, but they are all substrates on which orchids rely to stabilize the plant and grow and develop. 1. Potting soil formulas. In East China, orchid growers generally like to use orchid mud from places such as Shaoxing and Yuyao. In recent years, Mount Emei He Wang Pai Xiantu has also been welcomed by people, but these potting soils are limited in quantity and expensive, and can only be used for repotting. Large-scale field planting requires hundreds or thousands of tons of potting soil, so local materials must be used. After many years of practice and repeated screening, we determined that the best formula is: four parts yellow sandy soil, four parts sawdust, and two parts river sand; if using yellow loam, then one part river sand, one part sawdust, and one part yellow loam. All are thoroughly mixed. The pH value of the prepared potting soil should be between 6.5—6.8, loose and breathable, with excellent water retention and air permeability, and comprehensive nutrition. River sand and sawdust serve to conduct water and air; sawdust is decomposed by bacteria and can slowly release nitrogen, phosphorus, potassium, and so on. Yellow loam also contains a variety of trace elements. After many years of observation, this formula is very suitable for orchid growth. It is especially suitable as a substrate for domesticatingcultivationof wild orchids, suitable forCymbidium goeringii、Cymbidium faberi, and also very ideal forCymbidium ensifolium、Cymbidium kanran, with flowering rate and stress resistance both significantly increased. 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, as well as the decomposition of bamboo leaves and sheath shells, this soil becomes loose in structure, well drained, and has a certain fertility without being excessively fertile, making it 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, with sandy loam being the best; second, the age of the bamboo clump planting, the longer the time, the more fully the bamboo roots, bamboo leaves, and bamboo rhizomes act; 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 green manure (Chinese milk vetch). Mix vetch bran with bamboo root mud or ordinary sandy loam, pile it up, and decompose it, and it becomes vetch bran soil. Its preparation method is: choose a rain-sheltered site, spread a layer of soil, then a layer of vetch bran, then pour once with *manure water, and pile up layer by layer in this way; after piling, 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 potting soil in proportion. 4. Leaf mold. Use fallen leaves or green grass and tall stalks piled up and watered or fertilized, coated with thin mud to seal, and made through decomposition and screening. It is best to use green grass that has not set seed, and after full decomposition, kill pests, diseases, and weed seeds, otherwise there will be many weeds in the orchid pots later. 5. Mountain soil. That is, the mountain forest soil where wild orchids originally groworchids'. It is formed by dead branches and fallen leaves accumulating and rotting over many years and mixing with the soil. Naturally formed leaf mold contains rich humus, is loose and breathable, and is very suitable for orchid growth. When transportation is convenient, digging up mountain soil in large quantities to plant orchids is relatively simple and economical, and it is even better for domesticating raw orchids. The humus soil under broadleaf forests, especially the leaf mold under chestnut trees, is a very ideal soil for orchids. 6. Pond mud. In conjunction with winter repairs of ponds and fish ponds, dig out the mud, sun-dry it, and then crush it into fine particles. It can be used forcultivatingall 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 fertilizers such as fermented and decomposed soybean cake and rapeseed cake, to promote improvement of soil structure and enhance fertilizer efficiency. After turning and mixing evenly many times, sieve it again. This soil is nearly neutral and not as good as humus soil. Therefore, it is used only reluctantly when there is no suitable humus soil or mountain forest sandy loam, and is mostly used forcultivatingcoarse orchid varieties. 8. Cow dung soil. Crush and grind dried fermented cow dung into fine powder, mix it into sandy soil or the topsoil of field soil, and prepare it in a 1:3 ratio. It is best to choose cow dung from cattle fed dry feed in winter, because although the dry forage is finely broken after rumination in the cow's stomach, it still retains some elasticity, is plant fiber, and contains certain nutrients. This cow dung soil is soft and rich in fertilizer, and is extremely suitable for the aerial roots of orchids. In Taiwan, China, orchid circles often use this cow dung soil as a filling material for cultivating terrestrial orchids, with very good results. In foreign countries, for cultivating terrestrial orchids, generally 5 parts humus soil or leaf mold plus 1 part sand is used; or 3 parts peat soil plus 1 part river sand, mixed with crushed dried cow dung, fully mixed before use. The cultivation substrate for epiphytic orchids is mainly moss and ferns, with a small amount of leaves, small pieces of charcoal, and crushed dried cow dung added. Before using soil to plant orchids, expose the soil to sunlight for disinfection and sterilization. In summer, spread the soil out and let it sun-expose for more than 3 days, which can kill the pathogens and insect eggs in it. Before use, the potting soil should have its pH value measured and adjusted. For soil that is too acidic, lime can be used to adjust it. For soil that is too alkaline, use superphosphate, ferrous sulfate, and so on mixed into the soil. In short, it is suitable to control the soil pH value at slightly acidic to neutral (that is, pH5.5—7). Using organic fertilizers, such as green grass and leaves composted into fertilizer, and adding them to the soil to change the soil acidity and alkalinity is a better method. In addition, before planting orchids, the nutrient soil should be screened and graded, separating large particles from small particles. When planting orchids, place the large particles at the bottom of the pot to facilitate drainage. At the same time, the degree of soil dryness and moisture should also be adjusted well; it should not be too wet or too dry. It is best to ball the soil in your hand and squeeze hard so that the soil can form a ball; then open your hand and shake it a little, and the soil disperses again into granular form. This degree of dryness and moisture is suitable.