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.

[Leafmite]

Insects/slugs/snails don't seem to like the red lava rock nearly as much as they liked the bark and moss...and potting soil. I get critters in the pots of my soil-based plants but the red lava rock seems rather unpopular. I do use basket pots and this might help a great deal, too.

[MrHappyRotter]

Originally Posted by Stray59

I just keep mine inside as I don't care for the additional hassle.

I absolutely agree with this statement!

I set some of my houseplants outside in the warmer months, and maybe a few orchids. But, these days, I keep the majority of my plants indoors year round.

The main advantage to growing outside is that the plants do seem to go through a growth spurt (due to the rain, added fresh air, better lighting, good mojo).

But, the disadvantages are things like wind knocking things over and damaging them, falling branches from trees, hail damage, and pests.

Ultimately, my decision to stop growing outdoors came down to the pests. I prefer to minimize my use of pesticides, and every year, it seemed like some new critter became an issue. No matter how much I'd spray, I'd have ants or scale or slugs. I'd have birds and squirrels unpotting things or knocking them over.

The final straw was the year that the American roaches had a population explosion. They were everywhere. I sprayed and sprayed and sprayed some more. I drenched plants before bringing them indoors, and yet, a few months after coming in, the babies started showing up. Fortunately, they don't live long indoors generally, and they aren't like other roach species that live on trash and food scraps, but they still aren't pleasant. After that, I opted to stop putting my plants out.