Perlite and Sponge Rock

[Bolero]

Are they the same thing?

Also what is rockwool?

[kmarch]

I think perlite and sponge rock are the same thing, very porous rock. Rock wool is somethign I dont' see very often any more. In the US it was really going out fo style about the time I started growing orchids. It's a cottony spun rock or glass or something, not exactly sure what, but it was used to retain moisture much the same way we'd use sphag.

[Orchidementia]

Perlite is actually volcanic glass. Everything you ever wanted to know about perlite can be found at www.perlite.net (who knew?)

[kid a]

I think bast uses rockwool for most of his plants. Maybe he will see this thread and chime in

[Bolero]

Ah I thought it might be the same thing.......thanks guys.

[peetree89]

Rockwool, as someone has already said, is volcanic glass spun very thin and made into something that looks a bit like insulation. It absorbs water well and retains it, but also dries out quickly so it is good for preventing rotting roots. I use perlite on my own orchid (a phal) and it seems to be doing very well in just that. You have to make sure you water enough and feed regularly though as the perlite doesnt absorb much nutrition.

[Bolero]

I've started using it in my potting mix for both Masdevallias and Paphs. Not sure if I will use the perlite for anything else at this stage.

So I'm using bark, charcoal and perlite.......hopefully it works well. Although I have to say I didn't lose a single plant in the coconut and they all had great roots. SO hopefully I won't live to regret changing my potting mix for the above plants.

[digitalgate]

master learn something today.