Growing with purely peat, pumice, compost and worm castings?

xerb said:

I have great respect for the Hawaiian biome and the ganga produced there. I have often wondered about the lava rock which forms a base for all soils there. I used to find ornamental lava rock for free on Craigslist and crush it. Put a layer down on your cement driveway and then put a piece of plywood on top. Run your car over it everytime you pull into the driveway.

Much easier, buy lava rock crushed down to the size you want.
It is heavier than perlite, but in no-tills who cares?

Your proposed simple mix is almost there, as others have mentioned, add a few more amendments and you're there.

But you already know this stuff if you used CC's suggestions for your no-till soil...

Click to expand...

I think it would be the opposite. In no till, i think some of the benefits you get from lava rock over perlite don't matter much.
I make my soil mixes 1/3 drainage material.
I like about 15% lava rock and 15% perlite. It is significantly heavier then perlite. It holds less air. It doesn't float when hand watered (because it holds less air). And it doesn't crush. It lasts longer. But if you aren't tilling, you probably won't be crushing perlite as much. It will also pack in a bit and be less likely to float with no till.

I have used it exclusively in mixes with no perlite. Perlite does perform a bit better. But it does nothing crushed to dust or floating away.

All the local landscaping and soil yards carry it for about 50$ a yard. The small perlite is about 90$ a yard. The chunky perlite is more.
They have it in 2 different sizes. A big one that is for decorative landscaping and the small one that is used in soil. It's a little bigger then the good perlite.

A cubic yard is 200 gallons. I have only seen it bagged once or twice like perlite.

The "lava rock" is actually called haydite.... they use it in bonsai... maybe this will help your searches

MrBungle said:

The "lava rock" is actually called haydite.... they use it in bonsai... maybe this will help your searches

Click to expand...

Never heard of haydite when I was doing Bonsai. We used Turface in Canada, granite (chicken feed), pumice (which is a type of lava rock (mostly used by Europeans)) and lava rock itself. Haydite is expanded shale.

They call it lava pumice allot. I can get it in black or red or mixed. There is no difference between colors.

I believe the fancy scientific name is scoria? But no one will have any idea what you are talking about if u ask for scoria.