Medium: transferring from stones to bark?
 

Recently received three mature orchids from Odom's. They are robust, healthy, perfect. One even has a bud. They are potted in small gray stones. I wondered if this is lava rock, but I think that they are simply gray stones. Plastic pots. Two of them are so tight in the pot that I could not even get the tag out. The one with the bud will be left alone for now. Water runs right through these-- they are super porous. I repotted one of then (it was crawling right out of the pot and so bound that I had to cut off the plastic pot) in a mix of the stones with orchiata in clay. Did not want to be too drastic in changing the medium and since it is inorganic there was no break down. And the roots looked good.

Most of my orchids are in orchiata, with clay pots. I would like to get these into the same or similar medium/pot so that they would be about the same as far as water retention and schedule as the other orchids. But I don't want to set them back. Not sure what to do with the other two -- keep the stones, mix stones with orchiata, as I did with the first one I repotted, or go almost full 100% orchiata. Would appreciate input on this . . . .

Could these white rocks be sponge rock, perhaps?

I'm sure they are not sponge rocks. They are gray stones. Like gravel.

Hmm I’d be interested to know what those are.
What I was going to suggest, assuming that it was sponge rock, is that you mix half and half. Half sponge rock and half bark. I’m not sure that the rocks in your orchids would hold any moisture so I wonder how exactly they got their water from. 🤔 what type of orchids are these? Maybe if we look at the plants needs, we’ll be able to better help you.

What sort of orchids are these? Some orchids do grow in stony areas, and you'll often find those (like rupiculous Laelias) potted in stone chips or gravel.

I agree with camille1585 that, to give advice, it might be helpful to know what the orchids are. Some orchids like to be watered often but need to drain really fast. Not all orchids will fare well with the same medium and watering schedule.

The orchids are: Rhyncolaelia Glauca, Epicattleya Burdekin's Surprise, and Laeliocattleya Mari's Song. The latter two are cattleya types and need quick draining but they are often grown in bark, as is the first one. I do use clay pots as they help with speeding drying and add humidity to the environment.

A member of my OS grows in stones only, and he waters daily. His plants are terrific. I transferred one (a Dendrobium tortile) from his rock to my mix (orchiata, perlite, lava rock) and it didn't miss a beat. So if you can watch the moisture level and give the plant what it wants, I wouldn't be afraid to change it up.

Thanks fishmom. Feeling somewhat more confident now about mixing bark in with stones.

Sounds like the stones are Stralite. I know that there are some Florida nurseries that use this stuff for many different types of orchids and a few of the orchid supply places based out of Florida that sell it. I believe it works in the same vein as lava rock or LECA in that it’s porous, inorganic, and only holds on to some moisture so it’s great for those humid and rainy climates. Not sure what the benefits are of using that over lava rock unless it’s just more readily available in those areas or maybe lighter weight? I wanted to pick up a bag of this and try it on a few of my Catts and Dens since I am already growing a lot of those in straight lava rock and LECA but, again, not really sure what the benefits are and lava rock is super cheap. You can definitely use any of these on their own or as part of a mix to help with drainage