ORCHIDS IN LAVA ROCK?

[Shawna]

I have some orchids growing in pots inside my home in lava rock. If I just set the pots outside from time to time will the lava rock medium attract ants or other bugs? Do not want to bring bugs back into my house

[ALToronto]

Anything left outside will attract bugs. Lava rock has nothing to do with it.

[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.

[Leafmite]

Roaches would definitely do it for me.
I'm not a big fan of pesticides, either. We use them on our fruit trees and I use them when there is no other option but I prefer safer methods. We will be getting lacewings this spring (the house plants will be kept away from the fruit trees this year for that reason). This should be an interesting experiment.

[MrHappyRotter]

Originally Posted by Leafmite

Roaches would definitely do it for me.
I'm not a big fan of pesticides, either. We use them on our fruit trees and I use them when there is no other option but I prefer safer methods. We will be getting lacewings this spring (the house plants will be kept away from the fruit trees this year for that reason). This should be an interesting experiment.

Good luck!

I'm not sure if you have American roaches in your area, but yes, they were more than enough to persuade me to keep my plants inside. Most years, we see them around here in small numbers during the hottest part of the summer, but several years ago, they were a plague.

These guys are very large roaches. They are big enough that they make audible noises (buzzes and clicks). They fly. And one of their "survival" instincts is apparently to fly towards danger (i.e. people).

[Stray59]

Yep, large, noisy roaches would get me and my orchids moved into the garage! And I had my orchids in regular clay orchid pots with the four slits down the side.. but still the slugs loved getting in the mix and I whereas I had bark for most, a couple were in the red lava rock as an area greenhouse used to use that for all their epiphytic orchids. I don't think the slugs were eating anything inside the pots, but would stay there for the moisture and cool temps during the day - then at night crawl up the pots and chomp away - I was constantly spraying with Malathion and finally just moved them all back in the house. Then it was spraying and changing media, etc. to be sure I wasn't growing an ant farm in the house - or worse, a herd of slugs!
Again, not worth the headache for me!
Steve

[Leafmite]

We don't have cockroaches like that, thankfully. That is probably the only real advantage of living where winters are absolutely miserable.
I use the basket pots so that helps a great deal on eliminating good hiding places.
I get the ants living in my non-orchids. Usually I just set out some baits or soak the pots overnight and the ants are gone but last fall, there was some type of tiny ant that didn't touch the baits and didn't drown. Granular rose system, watered into the soil very well, finished them off.

I have contemplated becoming a year-round indoor grower someday, though. It is really a pain to carry the plants inside and outside and with the crazy weather we've been having these past ten years, I just don't know if it is worth it any more. I tried lights this winter with the orchids and had a spider mite problem for the first time. I need to find a way to get the humidity higher under those lights. I might try a clear plastic drop cloth over the growing area this winter and see if that helps.

[MrHappyRotter]

Originally Posted by Leafmite

I tried lights this winter with the orchids and had a spider mite problem for the first time. I need to find a way to get the humidity higher under those lights. I might try a clear plastic drop cloth over the growing area this winter and see if that helps.

I've also had to deal with mites in the past, and they are something awful. They are a serious issue, and require significant effort to combat, but I *think* I've over come them.

Initial phase of treatment is a combination of contact and systemic pesticides, alternated treatment. The organic and natural stuff isn't enough, go for the big guns. Repeat every 10 - 14 days, per instructions of whatever solution you use, make sure you check the label to make sure what you're using is effective against mites.

After primary treatment is done, neem or other horticultural oils used regularly as a preventative are sufficient. I prefer neem because it seems to also help with bacterial/fungal issues. If you catch the mites early enough, neem will knock them out, and you may not even need to reach for the permethrin or other options. Do your research though, since neem apparently can damage some plants.

You are correct that humidity is an important part of prevention, but even that may not always be enough. My collection is now large enough that keeping humidity above 50% isn't so hard these days, but when it drops, my weapon of choice is an ultrasonic humidifier with 1.2 gallon reservoir.