Re: non-acidic soils

Rick Walker (
Wed, 26 Jan 1994 15:00:47 -0800

> I have just gotten a few hibernacula of European _Pinguicula_ which
> require a neutral or basic soil medium. So we're back to an old
> question: How do I make a soil mix for them?
> Rob Maharajh (who sent them) suggested a 1:1:1 sand/perlite/crushed limestone
> mix. So where in the phone book do I look for crushed limestone?

I found crushed limestone at the local organic gardening shop (along
with granite dust, bone meal, etc). "Chalk" or "Diatomaceous earth" are
other synonyms for sources of nearly pure Calcium carbonate. Maybe you
could also crush egg-shells or (fresh-water?) oyster-shells.

"Dolomite" (CaMg(CO3)2) is commonly available and might be a suitable
substitute for Calcium carbonate. I don't know what effect the
Magnesium would have on CP, though.

Vermiculite is slightly basic (and buffering). This is what I use for
mexican pings.