Encyclia culture: Potting with stones, getting to the nitty-gritty with Encyclia alata

                There are four ways I use stones for potting.  The most common is as a layer on the bottom of the pot, to provide weight to make the pot more stable for orchids that produce towering, heavy inflorescences that dwarf the plant and can easily overturn it.  This also helps ensure that the mix drains well.

                Sometimes I use them in the pot to have something to hold the orchid fixed in place.  I usually do this when using coarse potting media that initially provides little stability to the plant.  In this case I tie the plant to a stone and place the stone into the mix.  “A wobbly plant is a dead plant” as my friend Jose Oliveras uses to say.   The stone provides the plant with a firm anchor until its roots can get a grip on the media.

In rare cases, I use it as potting media for particular plants that are very intolerant of any potting media that when it decays starts retaining too much water or that can be turned into slush by insects bacteria or fungi and will smother the roots by creating areas that impede the flow of air.

In the case of the Encyclia alata in the photo, the orchid is growing in side of a wire basket that has a two-inch layer of pebbles inside.  As you can se the plant has been growing for a while in the basket, slowly increasing in size.   The younger pseudobulbs are not in contact with the media, they are about two inches over it.   The roots grow toward the basket and eventually enter the media.

On occasion I have used stones to hold the orchid in an empty pot.  In these cases, the plants are attached to a single stone and there is no media in the pot.   I do this with plants that produce larger, stronger root systems if the roots are allowed to grow with no media to confine them.  I used to grow Cattleya Jose Marty “Mother’s Favorite” in this way.    

Using stones as a potting media has the disadvantage that they are heavy.  The wire basket in which Enc alata is growing weights quite a bit.  However, the heavy weight has its benefits.  This Enc alata can produce a four feet tall inflorescence, with dozens of flowers.   The weight of the stones helps balance the weight of the inflorescence.

                Because stones don’t decay, you have to provide the plant with a balanced fertilizer.   During the growing season you have to really make sure this plant is fertilized regularly or the plant will produce smaller pseudobulbs that it could.   Stones are not water retentive, so the plant has to be watered often when during its active growth phase.

                Compared with the other media I use, stones are a very minor component of my orchid growing.  But they can be useful in particular cases for plants that have specific needs.    I prefer to use smooth river pebbles.    On one or two cases I have used them to cover fibrous potting material to stop birds from stealing it.

                A final note, don’t just grab any old stone and stick it in a pot.  I prefer to use volcanic rock because they tend to be chemically inert.  Some stones will react with the acids in the media and alter the pH of the mix, some plants like this, others don’t.  Never use stones that are crumbly or might leach unwanted chemicals into the mix.