Pros and cons of lava rock

[stylingpat]

I'm been switching all my orchids over to a lavarock/orchiata mix at about 50/50. I really love it and all my plants have responding very very well to it. And if I want more moisture for my phals I mix in sphag in the top portion of the mixture

[Dante1709]

As many other people have mentioned, I use it to weigh down some pots. I also find it useful to mix in bark mixes and add extra aeration. I originally had them for landscaping, so I put them in a plastic bag and hammered them to smaller bits.

[DeaC]

I recently received Bulbo. macraei in lava rock-a medium new to me. It's been hot here in central Jersey and so I water it daily and keep it outside shaded now. I do see new growth so that's encouraging. I've only seen lava sold at shows but will try it again in other plants.

[Optimist]

I love lava rock. I use it with nearly every "mix" I make. Before lava rock, I was an orchid killer looking for guidence. The Cattleyas Love it. Dendrobiums love it with some small bark mixed in. I have it in cimbidium mix. I put a chunk under my twinkle. In the phals I have lava rock and sphag moss. I just recently read a 100 year old orchid book and they specified filling the pot 1/2 to 1/3 of the way with lava cinder, broken pottery, or stone. This makes sence to me. The root zone of the stem or bulb gets a bit of humidity, and the lower regions of the pot ( ceramic) have fabulous drainage.

Pros: no root rot. Cons: you must water each day in summer.

Me, I'm a tiny house, home garden, vegan, DYI hippie type. I would rather commune with the orchids each day as a meditation, than take short cuts. Isn't that the reason we have them?

[ramonypony]

Originally Posted by Ferns Daddy

I've been reading a lot about using lava rock for vanda's but I didn't find any thing about them here or maybe I just missed it when reading the threads on potting and repotting, could I use with other orchids too, I'm trying to learn as much as I can about growing and care of my orchids.

I love lava rock, it's inexpensive and multipurpose. I have some in my cattleya/laelia types, encyclia, maxillaria, dendrobium mixes. And in a vanda basket. I also put a thick layer of it at the bottom of a phalaenopsis' pot just to take up space because the root system wasn't large enough to reach the water at the bottom and I didn't want it to rot out. I don't know of any cons of it, it doesn't decompose of course and it's quite heavy which is a good thing for me. I think I read once that it's prone to accumulate salts which would be a con. It dries out fast which is a pro for me, could be a con for someone else.

[james mickelso]

An Old wives tale. The reason that tale got started was that as any moisture dries out on the lava the minerals like calcium carbonate/iron/organic sediments stay behind. Just like the white scale on the edges of the pots. Otherwise it holds no more than any other media. In fact I think it holds less as bark/moss/CHC/leca would absorb moisture/minerals.

[Vanda lover]

It seems to me that the minerals only form on the surface where it dries out frequently. I never see any on the pieces that are underneath. I flush with clear water often just in case and I've never had a problem with it.