permaculture

[Rick Valley <bamboogrove@cmug.com>]

> From: BK <lildragon@saber.net>

> I'm actually more interested in what
> lightweight mixtures would work, and what would want to grow there. I think
> I'd probably stay away from styrofoam,
styrofoam doesn't contribute anything but space, so it's pointless except as
a container perhaps. (like gardening in farmed salmon coffins)

>though perhaps perlite might be a
> possible addition. Then there is the issue of moisture, with 2 somewhat
> competing goals: drain it away fast in downpours, but keep some moisture for
> as long as possible.
The medium will only hold so much; and you'll actually want to hold as much
of a light rain as possible and minimize evaporation, which is why I'm not
sure about a suspended bed.
 
>I had never really thought of using silica crystals,
> its an interesting idea. Are there any relatively ecofriendly polymer
> absorbers to add? Perhaps some form of seaweed gel can absorb and hold
> water, like agar or some such.
seaweed gels do contribute to soil texture and moisture holding ability,
although they do not last as long (I presume) as polymer gels (about which I
have heard conflicting reports as to whether the actually help plants or
"make water available"

> Lastly, is galvanished hardware mesh a high
> risk in terms of heavy metals? It would primarily be zinc right? Is zinc
> rated high in bad metals, or are there other metals added to the zinc dip?
There's no such thing as pure; cadmium is a known contaminant of zinc in
galvanised coatings, and there's no need to needlessly add a cumulative
toxin to the environment.

But be sure and find a copy of the Conway Bros. doing "Raise the Roof" to do
the installation to. You can sing it "raise on the roof"!

-Rick