How to choose orchid potting medium? Sharing my practical experience

OrchidFor enthusiasts, the first problem encountered when growing orchids is choosing a potting medium. Books all emphasize that the potting medium should be loose and breathable, and must not hold standing water. There are many types of potting medium: leaf mold, fired clay soil, wood shavings, coarse sand, gravel, brick fragments, tree fern, etc. Exactly which potting medium is best is hard to conclude. It should be analyzed according to the specific local conditions. Based on my experience growing orchids over these past few years, I will share some understanding. When I first started growing orchids, according to books and related materials, I began choosing a potting medium fororchids. I only knew that the potting medium should be airy and loose, so I deliberately went into deep mountains and old forests to dig up two snakeskin bags of leaf mold; it was very soft and springy, but I forgot that Wuyishan is located in the subtropics, with annual rainfall of more than 1500mm and high air humidity. At that time, for the potting medium choice, leaf mold made up 50%, and I planted 16 pots oforchidsin one go. A potting medium mainly of leaf mold is relatively breathable, and in summer and autumn the growth was fairly normal. In winter and spring it was difficult to manage. Not watering for a long time would not do, and watering was very troublesome: with a small amount of water, the surface of the potting medium was wet while the inside was dry. Watering the entire potting medium thoroughly took more time, and once watered enough, it would not dry easily for half a month, so the orchids soaked in moisture for a long time. Add to that the winter and spring seasons, with either frost or moldy rainy days, and root rot and seedling rot were serious. In the second year, to address the problem of poor air permeability, I removed garden soil from the potting medium, replaced medium sand with coal cinders or gravel the size of mung beans, and reduced the proportion of leaf mold. Granular potting medium made up 60% and leaf mold 40%, and I planted more than 20 pots. By summer and autumn, the number of waterings increased somewhat compared with the first year. Watering was easy, the potting medium's water permeability improved, and air permeability was also good. In winter and spring, management was much more convenient. After watering, the potting medium began to dry in 3-5 days. Although winter and spring are not very favorable for the growth oforchidflowers, whether outdoors or indoors, seedling rot and death basically did not occur. Apart from a few weak seedlings losing leaves and some leaves having scorched tips, most grew normally. The root survival rate rose to about 80%, and a small number of roots had some black spot disease, but the roots were clearly robust. In the third year, the choice of potting medium was improved again. The granular potting medium was mainly broken brick, gravel, coal cinders, coarse sand, Xiantu, charcoal pieces, and tree fern, with leaf mold and wood shavings also selected. The granular material was increased in size, combining broad bean, soybean, and mung bean sizes. Since Wuyishan has a lot of gravel, I used gravel plus some broken brick and coarse sand as the main components, accounting for 3/4 of the potting medium, with leaf mold or wood shavings accounting for 1/4. The granular potting medium must combine more than two kinds. For growing variegated-leaf orchids, granular material accounted for 4/5 and leaf mold 1/5. For planting stunted seedlings and weak seedlings, I used only granular material without adding any leaf mold. Large granular material was placed in the middle, and small material on the surface. I planted more than 30 pots of orchids. When watering, I found the air permeability first-rate. It penetrated while being watered. Watering in summer and autumn was a bit laborious; by covering the pot surface with some water grass, watering once a day was enough. In winter and spring the advantages were obvious. Because water permeability was excellent, the potting medium dried easily, was not affected by freezing or the moldy rainy season, and there was no worry about root rot or seedling rot. Scorched tips almost did not exist, the root survival rate reached more than 90%, root rot was extremely rare, and black spots on roots were also extremely rare. The potting medium was airy, andorchidwhite silk disease and black spot disease were relatively reduced, the germination rate increased, management was convenient, and the medicines used were reduced by more than half compared with the past. The potting medium should be breathable, and the air permeability of the orchid pot cannot be ignored either. For the orchid pot, choose a pot with drainage holes at the bottom and air holes on the sides as the best. If there are no air holes on the sides, it does not matter. You can cut a cola bottle or mineral water bottle into two halves, burn honeycomb-like holes about 2cm2 in size, more than 10 of them, and cover them over the drainage hole at the bottom of the pot, which can also provide a fairly good air-permeability effect. For orchid pots with air holes on the sides, covering the bottom hole with a perforated cola bottle is even more ideal and can better serve the purpose of air permeability. This is very effective for cultivating young, weak, and small seedlings. I planted 5 pots of weak and stunted orchids, some with no roots at all, all in granular potting medium. The orchid pots had bottom holes and air holes on the sides, and I also covered the pot bottoms with perforated cola bottles. After three months the roots began to grow, some grew four leaves, and not one died. Granular potting medium has advantages and disadvantages. Its shortcoming is that it has no nutrients at all, so a appropriate amount of thin fertilizer must be added during watering, fertilizing once every half month and spraying trace fertilizer on the leaves once every month. (Wuyi orchid grower)