What soil is best for growing orchids? Soil mix methods and key selection points

Orchids are fleshy-rooted plants, and they require loose, fertile, well-drained, slightly acidic soil, and mountain soil is most commonly used. However, when potting them up, at the drainage hole in the bottom of the pot, more shards should be used, and a thicker layer. On top of the shards, a layer of broken mud granules should be spread, and on top of the broken mud granules, fine mud should be spread before the orchid can be placed into the pot, after which mountain soil is added. This planting method is mainly based on the orchid's habit of disliking dampness and being averse to waterlogging, so as to keep drainage unobstructed. When using mountain soil, if 1/3 coarse-grained river sand is also added, then drainage is even better and it conforms even more to the orchid's growth habits.

For cultivating orchids in the north, soil that contains a large amount of humus, is loose, and is well-drained, neutral to slightly acidic soil is best. Quite a few landscaping units in the north collect and transport mountain soil from places such as Shaoxing, Zhejiang, to cultivate rare varieties. Although this is beneficial to orchid growth, the water quality in the north is harder, so it must be replaced once every two to three years, and long-distance transport makes the price relatively high. In recent years, trials using locally produced grass peat soil at 3 parts plus 1 part river sand, mixed with some organic fertilizer (which needs to be piled for a period of time) as potting soil for orchids have also shown fairly good growth. In northern mountainous areas, leaf mold from under broadleaf forests, leaf mold made by piling broadleaf tree fallen leaves, and culture soil containing 6 parts humus can all be used to cultivate orchids.

Epiphytic orchids potted in the north include Dendrobium, Cymbidium hookerianum, and Cymbidium eburneum, and they cannot be potted in soil. The commonly used growing materials are sphagnum moss, fern roots (Polypodium roots or Osmunda roots) with a small amount of broadleaf tree leaf mold, small pieces of charcoal, and dried cow dung as the best; in addition, broken pot pieces and crushed brick blocks can also be used to pad the bottom of the pot.