What growing medium is best for planting orchids?

Orchidsare planted differently according to local customs. For example, in the Guangdong area, sun-dried pond mud is often broken by hand into granular pieces for growing orchids; in the Zhejiang area, mountain soil is mostly used as the soil for growing orchids; in Beijing, peat soil mixed with some sand is used; in Wuhan, it is customary to use coal cinders or burnt soil that have been left for more than a year to grow orchids. Nowadays, the above traditional methods have gradually been abandoned, and non-soilcultivationsubstrates such as ceramsite, broken bricks, volcanic rock and charcoal are used. These substrates have the advantages of good aeration and drainage, not compacting, and being easy for orchid roots to grow in, which makes clay soil pale by comparison. Different materials have different pros and cons; their properties and characteristics are briefly introduced as follows: Tree fern root -- also called snake wood, it is made from the aerial roots grown from the trunk of a plant, chopped into thin strips of varying thickness. Tree fern root drains well and does not rot easily, making it most suitable for growingorchidsin the rainy southern regions. But its shortcomings are that it dries out easily and readily attracts ants to build nests inside it, which is harmful toorchidroot growth. Sphagnum moss -- the sun-dried plant body of peat moss, its water absorption and retention capacity is extremely strong, and it is not suitable to be used directly as an orchid growing medium. In orchid-growing circles, sphagnum moss is mostly laid flat on top of the orchid pot to increase humidity for the orchid plant. When sphagnum moss rots, it exudes extremely acidic liquid, affecting orchid root growth, so it should be replaced promptly. Bark -- including pine bark, longan bark, etc. Bark has good water absorption and drainage, and is rich in organic nutrients, which is extremely beneficial toorchidgrowth. But being prone to rotting and breeding pathogens is its shortcoming. Gravel -- including volcanic rock, pumice, small pebbles, red stone, ceramsite, etc. Growing orchids in gravel has the advantage of good aeration and many voids that make orchid roots easy to extend. But the lack of nutrients and the easy loss of water and fertilizer after application are its shortcomings. Charcoal particles -- have adsorption and sterilization effects, and good drainage and aeration. Because they are slightly alkaline and lack nutrients, they are generally mixed with other growing media. Broken bricks -- have good water absorption and aeration, but easily accumulate base-free salts and breed pathogens, which is unfavorable to orchid growth. They are mostly mixed with other growing media. Leaf mold -- it is best to use leaf mold brought back from the orchid's native habitat, or leaf mold can be artificially composted. Leaf mold is rich in nutrients and well aerated, and is most suitable for orchid growth. But its strong water retention makes it easy to breedpests and diseases. Pond mud -- when used as a growing medium it is mostly broken into granules. Pond mud has moderate pH and fairly sufficient nutrients, and is very beneficial to the early growth of orchids. But after being exposed to sun and rain for a period of time, it will loosen and compact, which is extremely unfavorable to root respiration and hinders orchid plant growth. Therefore, its use as an orchid growing medium has been gradually phased out, and more people use it mixed with other substrates. An ideal orchid growing medium should have good drainage and aeration, contain sufficient nutrients, and not easily rot or compact. To obtain this ideal growing medium, you have to mix it yourself: one part leaf mold mixed with one part pumice, or one part tree fern root plus two parts broken bricks or small gravel, is most suitable for growing orchids.