The suitability of growing media for different plant groups: how to choose the right growing medium for different plants

A brief discussion of the group suitability of growing media Growing medium is the very foundation of an orchid's survival and continuation. Through the ages, orchid growers have never dared to treat it lightly; their strictness in choosing soil borders on the harsh, which shows how highly they valued it. Yet when studying ancient texts, what is valuable is not to be bound by antiquity, but to keep the essence and discard the dross. Therefore, for orchid growers, growing medium should be understood in terms of the group suitability for others who later introduce and divide seedlings, and as far as group suitability goes, leaf mold soil ranks first. Second, finding soil: although superior leaf mold soil is not easy to obtain, knowing where it is found is not difficult. You can look beneath rocky cliffs in mixed forests on high mountains; the higher the cliff, the better the leaf mold soil, and the reason is simply that fallen branches and leaves accumulate easily in such places. Third, collecting soil: when collecting soil, you may sweep away the undecayed leaves on the surface layer and take the thoroughly rotted soil below. Where the soil layer is thick it is about one chi, where shallow only half a chi. Its color is black, and when dry it appears earth-white; in the clods you can still see undecayed leaf veins. It is best to take it mostly in clod form. Fourth, soil properties: this soil is loose and porous, rich but not overly fertile, and its fertility is long-lasting; it moistens easily when dry, and its moisture-holding power lasts long. Compared with other soils, it is heavy when moistened and light when dried. Its virtue lies in holding enough water without leaching out; its shortcoming is that it easily breaks down after many years. Fifth, selecting soil: before sifting, leaf mold soil should first be sun-dried thoroughly so that it first clumps and can then be sifted. If the quantity is large, it can be divided into three grades: large, medium and small. For species seedlings, grades large and medium may be used, while the small grade can be used for seedlings of the "hope grass" type. Among it, thoroughly rotted dead branches that crumble easily when pinched and are rather loose and porous may also be mixed into the leaf mold soil; they are truly a superior fine medium for growing orchids. Only the undecayed leaves should be discarded and not used, for fear that when planted in the pot they may lie flat and cause water accumulation, and excessive moisture may produce stuffiness, which harms the orchids. If sun-drying for disinfection still leaves you uneasy, you may steam it once more, then dry it in the shade for later use. Sixth, blending the medium: in my humble opinion, leaf mold soil should not be blended with planting stone, for fear that it holds water too strongly, just like the leaf mold soil, causing excessive moisture in the pot and producing stuffiness. It is generally more appropriate to use brick granules, weathered shale and the like. The blending of the potting medium should be determined according to the condition of the seedlings as appropriate; for strong, vigorous seedlings the leaf mold soil proportion may be slightly greater than for poor seedlings, but it is best never to exceed sixty percent. Therefore, before planting, the amount of blending material determines the timing of future watering. Seventh, management: daily management is mostly seen in old posts and need not be repeated here; I will say only a word or two about watering and repotting. Watering should be mastered before the leaf mold soil forms a crust. What is a crust? It is when a small amount of water sprinkled on the surface of the leaf mold soil forms fine droplets; then the pot surface dries easily while the inside of the pot is still moist. At this stage you may lightly moisten the pot surface to prevent crusting, which helps later thorough watering. Second, repotting should not be done too frequently; one should know that the strength of leaf mold soil comes later, so two to three years is generally best, though of course it must also be determined by the condition of the plants