Best orchid potting mix – Materials and formulas

Orchid potting mix: finding the perfect substrate for orchids is not an easy task, but we are going to try to define what elements can compose it and how to mix them.

The orchid is such a special flower that it does not respond to any standard care of most plants. Neither in irrigation, nor lighting conditions, temperatures (day/night) and much less as far as land is concerned. And that is what we are going to try to address in this article.

How do the roots of an orchid behave?

This is a very broad question and it is the downside of this large group of plants. There are different types of orchids, with roots of very different behavior and therefore, equally varied substrates for orchids. Particularly and commonly, a classification of terrestrial and epiphytic orchids is established.

In general, we can say that the most common orchids that are usually kept are epiphytic and consist of aerial roots. Epiphytic means that they attach to other plants, not specifically to the ground. We normally speak of the genus Phalaenopsis Vanda or Dendrobium, three of the most famous. There are differences between them. The most comfortable are the first ones because their aerial roots start from the base. Vanda , for example, generates them higher up, between the leaves.

This means that the substrate must not be regular soil . Surely you have seen transparent containers and things like tree bark or similar. This is due to the fact that the roots are aerial, green, have a chlorophyll function and their main function is to support the plant, collect humidity from the environment and feed on the micronutrients that “slip” through the bark of the tree.

Many people think they are parasites but they are not, because they do not prevent or reduce the growth of the tree or plant they cling to.

Making a summary we can look at the importance of the roots in these plants. They are practically totipotent!

  • They hold the plant to the substrate
  • They do chlorophyll function
  • They capture nutrients
  • And above all, they capture environmental humidity. This is crucial for its proper development.

So what is the ideal orchid potting mix?

The easy answer is that there isn’t. There are as many substrates as orchid varieties, but what we can do is list the most used materials. Go for it.

Conifer bark. We start with the most used. And there are several reasons. 

It is perhaps the most seen element in the nursery orchids that they give us. If rigorous fertilization through irrigation water is not going to be followed, the bark is a very good nutrient reserve element as it decomposes.

It is highly recommended to use it for several reasons:

  • It provides nutrients unlike other materials such as perlite or rock wool.
  • Being coniferous, they acidify the environment. Orchids in general need a fairly acidic