Orchid Soil Substitute

Soil Substitute Needs

• Orchids require excellent drainage above all else in a soil substitute. Too much moisture causes the roots to rot, killing the orchid. Soil retains too much water and dries out too slowly, so it's not a suitable potting mixture. The roots also require aeration, which soil can't provide because it compacts too much. A loose soil substitute drains quickly and allows air circulation around the roots, so that the orchid doesn't suffer from rot issues.
  
  

Ingredients

• The main purpose of a potting medium for orchids is to provide support for the plant. Coarse organic materials provide support while also supplying proper drainage and aeration. Both homemade and commercial orchid media typically contain a combination of fir bark, peat moss, tree fern fibers or coconut fibers. The mixes can also contain inorganic materials including perlite, blue rock and charcoal. The ingredients are either naturally sterile, as with peat and perlite, or sterilized before use to ensure no disease organisms are introduced to the orchid.
  
  

Potting Media Recipe

• Choosing the materials to include and in what amount depends on the specific needs of the orchid variety and the growing conditions provided. Some experimentation is necessary to find a successful mix. Generally, a mixture containing 1 part each fine-textured organic material and an inorganic material, combined with 6 parts of a coarse-textured material works well for most orchids. Use finely milled peat moss or tree fern fibers for the fine-textured organic materials. Perlite and charcoal work well for the inorganic material. Larger pieces of fir bark provide the majority of the drainage when used as the coarse material.
  
  

Nutrition

• The soil substitute ingredients provide minimal nutritive benefits to the orchid, so additional fertilization is needed. The rapid draining of the potting media causes it to rapidly lose nutrients. Regular fertilization with a soluble feed replenishes the nutrients. Soil substitutes that consist primarily of bark require a high-nitrogen orchid fertilizer, such as 30-10-10 blend. A balanced 20-20-20 blend is sufficient if the orchid media contains minimal bark. Apply the fertilizer at the rate recommended on the label to avoid overfeeding.