A Detailed Explanation of the Properties and Uses of Orchid Soil

Orchidsoil, commonly known as mountain soil, comes in many varieties, and good ones are no longer common. In fact,orchidsoil can be roughly divided into two types: yin soil and yang soil. Yin soil is ash-like, black in color, light in texture, and prone to growing green moss on its surface; because of its high humus content, it does not readily absorb water thoroughly once dry. The best comes from the mountains of southeastern Zhejiang. There is also yellow soil, which is ordinary mountain soil with little humus and a heavy texture;growing orchidsin it gives poor results. Yang soil, by contrast, is hard when dry, granular, turns brown when thoroughly wet, and has a sticky quality; moss rarely grows on the pot surface year-round, and it is heavy. It is mostly produced in the mountains around Lake Tai, the soil from Yixing and Changxing being of this kind; bamboo-root soil from some places is also very similar (but its granules break down more easily and tend to compact in the pot over time). In fact, both types of soil can groworchidswell. The boldest and most convenient approach is this: whenever using either type of soil, mix in 30%-40% rice-hull ash (it is best to let the rice-hull ash sit out in the rain for a few showers, so prepare it early; canteens and teahouses in some places all have it). If the soil is dry, you can mix in wet rice-hull ash when using it. For planting, unglazed clay pots in dark gray are best, and you can put extra charcoal chunks or crushed red brick at the bottom. After planting, water until water runs out of the bottom, then stop. If you plant Selaginella uncinata on the surface of yin soil, it takes root very easily. For yang soil, covering the surface with granular material is ideal. Some people say rice-hull ash is alkaline and they dare not use it, but in fact there is no harm in using it; the author has used this pure ash to cultivate prizedCymbidium goeringii、Cymbidium faberipseudobulbs, and all produced shoots that grew into plants; on checking them in the pot in early autumn, the roots had already circled around. If orchid enthusiasts think prized orchids are too delicate and it is really inconvenient to use this, that is fine too. For yin soil, you can mix in 20%-30% rice-grain-sized red brick granules; at home most people crush them with a hammer, put them in a woven plastic sack and beat and trample them to wear off the sharp corners, then sift them with a plastic container with holes of the appropriate size. The coarse pieces, after rinsing, can be used as bottom potting material; the fine ones the size of rice grains or mung beans go into a container with fine mesh, are rinsed with water to wash away the powdery dust, and after soaking in clean water for several days they are ready to use. If conditions allow, you can mix in small granules of pine-cypress orchid stone or pond-base orchid stone, with the same effect. For small seedlings or weak seedlings, the amount mixed in can be increased accordingly. If it is yang mountain soil, then make a sieve with window screen, sift out the powdery fine dust and discard it, and you can also sift out the extra-large granules for the bottom of the pot, and then plant orchids with confidence. For weak or old seedlings, you can mix in a small portion of pine-cypress orchid stone or perlite granules. In this way, light soil is mixed with heavy medium and heavy soil with light medium, each bringing out the best in the other. All the soil methods above are best used with unglazed clay pots in dark gray (the kind whose outer surface can become thoroughly wet and readily grow moss is even better), and wide-mouthed ones are the first choice. When planting, the traditional seated planting method is best; used for maintaining orchid seedlings from old nurseries, this method makes repotting and rejuvenation very easy, produces strong shoots, and brings flowers quickly. For imported seedlings, soilless indoorcultivationmakes seedling care harder, tends to produce small shoots, fails to send out roots, and causes old seedlings to decline.Before planting orchid plants, for the former it is best to spray with water and mix until moist, so that after watering there is no phenomenon of the middle drying out and failing to absorb water; for the latter, after planting, water around the rim or simply soak the pot. Such methods are suitable for growing orchidsin courtyards and patios; during the growing season, even if there is somewhat prolonged rain, there is no harm in letting them get rained on. The petal-type flowers of Jiangsu and Zhejiang, which are mainly grown for flower appreciation, are typical terrestrial orchids, native and soil-grown, so of coursecultivatingthem in soil is most reasonable. Reasonable use of soil can make flower colors vivid and the petals thick in substance and soft and glutinous, commonly said to have a "jade head," while the orchid leaves are short, broad and firm and the pseudobulbs thick and robust, truly small seedlings with large flowers, making the contrast even stronger. The "tempering of plants" currently advocated in orchid circles also requires reasonable soil conditions; otherwise, once "out of" the uniquely favored mountain environment,orchid plantswill inevitably end up "battered and bruised," with yellow leaves and withered roots! So for family hobbyistsgrowing orchidsfor appreciation, it is still appropriate to cultivate them in a medium containing soil. You can mix more or less high-quality orchid soil into the granules (sold at flower markets in all the major cities of Jiangsu, Zhejiang and Shanghai). But orchid soil is best not mixed with other soils. As mentioned earlier, dry Xiantu has water-repellent properties, while orchid soil must be used with alternate wetting and drying; mixing the two may later cause the undesirable phenomenon of water running out of the bottom hole while not penetrating into the pot, needlessly adding losses. I wonder whether orchid enthusiasts have noticed that when admiring photos of orchids, pots with Selaginella uncinata planted on the surface always have heavy, substantial flowers, probably because of the effect of using orchid soil. (Jiangsu - Wang Xinlei)