What are the common potting media? A detailed explanation of their characteristics

Traditional in the Wuxi area,cultivationall used surface soil collected from mountain forests (orchid mud) tocultivateorchids, most of which had to be transported from Nantong Junshan, Yixing Dongguan Mountain, Fuyang Xiangshan, Shaoxing Lishui and other places. But at present, to protect the ecology, forest areas have been closed for afforestation,orchidmud supplies are running short. Adopting new techniques tocultivateorchids has become imperative. Therefore, in the mid-1980s I began trials on selecting artificial culture media for cultivatingorchids, in order to gradually replace orchid mud. The artificial culture media tried included: sawdust, recycled waste soil, hawthorn seeds, sphagnum moss, ceramsite, coconut husk chips, bark chunks, brick granules, charcoal, palm bark, perlite, plastic foam granules, etc. Among them, the more ideal media are the following. One, (Shi Zhi) stone (Shi Zhi) stone is a porous, spongy, multi-flake body, neutral, able to retain water and nutrients. According to 3 consecutive years of observation ofCymbidium goeringii(including some rare varieties),Cymbidium ensifolium、Cymbidium faberi、Cymbidium sinenseand others cultivated in (Shi Zhi) stone (compared with the control group cultivated in orchid mud), the annual new shoot sprouting rate of potted orchids planted in (Shi Zhi) stone was 5%-12% higher than that of the control, and the new shoots were 0.5-1.5 cm longer. The orchid plants appeared sturdy and vigorous. Flowering was also no worse than that of the control group. However, (Shi Zhi) stone used for cultivatingorchidscannot be used multiple times. Two, sawdust Sawdust is a substrate material with a wide source and very low cost, and sawdust from broadleaf trees is preferable. In addition, the sawdust must be soaked in water for more than 10 days and fully decomposed before use. According to trials onCymbidium goeringii、、Cymbidium faberi、Cymbidium ensifolium、Cymbidium sinenseand others, their annual new shoot sprouting rate and new shoot length were similar to those of the control cultivated in orchid mud, and the orchid plants were sturdy and vigorous. It is especially suitable for planting plants whose roots were originally poorly developed. Therefore, sawdust is a very suitable culture medium for orchids such asCymbidium goeringii、Cymbidium faberi、Cymbidium ensifolium，Cymbidium sinense. However, orchids planted in sawdust should be repotted within 1-2 years; otherwise the root growth of the orchids will be affected. Coconut husk chips are more effective than sawdust, but their source is limited. Three, hawthorn seeds A by-product after hawthorn processing, with no utilization value in the producing area. Entrusted by orchid enthusiasts in the producing area, trials were carried out on Cymbidium goeringii, and even some precious Cymbidium goeringii varieties grew well. If further puffing treatment can be done and they can be processed into media of different particle sizes, they can be repeatedly disinfected and used. Hawthorn seeds should be a medium with good development prospects. Four, ceramsite A red pottery clay product with a round exterior and honeycomb-like pores inside, available in specifications of various particle sizes. It has medium water-holding capacity and good aeration. Similar to foreign fired stone, it is widely used in orchid cultivation, and using it to cultivate Cymbidium sinense and semi-epiphytic orchids and others gives excellent results. However, ceramsite has a high cost and its promotion is limited; substituting brick granules gives similar results. Five, palm bark Using stripped palm bark, it can be used after slight processing, and can be used to plant epiphytic orchids. In particular, it can be used for many forms of planting, such as binding, board planting, hanging planting, etc., which is very convenient. Six, bark chunks Made by processing the bark of broadleaf trees according to different particle sizes, it is best for cultivating aerial orchids such as Phalaenopsis, Cattleya, Vanda, etc. However, because bark is light in weight, it is somewhat difficult to support large plants, so artificial supports must be added. A similar material is charcoal. Charcoal has been treated with high heat, has nopests or diseases, has many capillaries inside, and has good water absorption. It also drains quickly and can be used to plant Phalaenopsis, large-flowered Cymbidium, etc., but artificial supports must also be added. In short, there are many artificial culture media that can be used. Generally speaking, for terrestrial orchids and species with smaller plants, culture media with smaller particle sizes should be selected, while for epiphytic types and species with larger plants, culture media with larger particle sizes should be selected. Mixed artificial culture media are generally made by mixing orchid mud with sawdust, (Shi Zhi) stone, leaf litter, etc. The proportions should be determined according to theorchidspecies being cultivated and the environmental conditions. (Jiangsu / Zhou Juying)