ORCHIDS IN LAVA ROCK?

[Stray59]

Anytime you set a plant outside, you are subjecting it to any insect pest that are around. I have found that the loose media most orchids are planted it, and lave rock is a good example, tends to attract the "moist shady" insects - slugs, pill bugs, and sometimes ants. Also, orchids themselves are particularly susceptible to scale and mealy bugs, due to the numerous growth sheaths that so many of them have.
If you are putting them outside, I would really suggest you use a good systemic or a regular insecticidal spraying. I put a bunch of phalae's hanging from a tree in my front yard and the slugs and grasshoppers ate huge chunks out of their leaves.
I just keep mine inside as I don't care for the additional hassle, but I know a lot of people who will put their orchids out every year and have better results than I did.