Know your "Potting Mix" components

Records show that Chinese were cultivating cymbidiums 6000 years ago and Japanese and Asians 2000 years later. In Europe, Greeks knew terrestrial orchids 2500 years ago, orchid bulbs were part of the Greek diet since.

Details about cultivation techniques, potting mediums, etc, from those days are not known. Three centuries ago, the beautiful and exotic looking tropical orchids from Asia were introduced to Europe. Originally, Europeans thought that orchids were “parasites” growing on trees and therefore growing orchids in Europe was unthinkable. Planting the right trees under cover in any European botanical garden to cultivate these orchids was not possible.

The misunderstanding was realized soon and orchid lovers began experimenting with various mediums and growing conditions. It was clear; in nature orchids live on the ground, on rocks or trees and take moisture and nourishment from their surrounding environment. Therefore, it was important to recreate the environment they live.

Today, we still believe that it is important to recreate the environment they live. However, we do not do things we preach. We use numerous mediums and potting mixes to satisfy basic orchid needs such as: Anchorage, retention of water, good drainage, slow decomposition and acceptable pH.

Many growers refuse to accept that the failure to grow orchids successfully is at least 50% directly related to two things: Pot size and potting mix. There is NO “best” medium. Each medium requires different management and there is no point copying others, what works for your neighbor may not work for you. Try to find the potting mix that suit your orchids and works best for you.

A friend insists, “Everything is a matter of management”. Management of plants is related to the control of temperature, humidity, air-circulation, watering, use of fertilizers, pesticides, insecticides, etc. You cannot manage a house before you buy it or build it. With orchids, you must find an orchid plant suitable to your area, and use the right size pot and medium that suit the plant and your facilities and the way you are going to manage it.

Introducing “potted” plants has its risks, not only you don’t know if the plant has healthy roots but also because of its potting mix, it may require special attention. Re-potting a plant is sometimes necessary so that all plants in your orchid house can be managed easier.

Orchids require a fresh, fast-draining, water-retentive medium for good growth. The pH must be 6 – 6.5 (perfect pH 6.3) for the nutrients to remain in solution. Tap water has a pH just under 7; rainwater has a pH around 6.4.

Bark-based mixes drain well, retain little moisture but break down quickly and need more Nitrogen. Peat-based mixes, retain moisture, but require more frequent re-potting. Inorganic mediums are good but need a lot of experimenting to get it right.

The potting materials used today can be split into two major groups:

ORGANIC MATERIALS: a. Un-Treated Organic Materials; b. Pre-Treated Organic Materials; c. Organic Compounds.

INORGANIC MATERIALS: a. Un-Treated Inorganic Materials; b. Pre-Treated Inorganic Materials; c. Inorganic Compounds.