On Mon, 9 Jan 2012 03:48:29 +0000 (UTC), gregz wrote:

Interesting about the sand. I would probably want to heat up also.
Last year I tried soaking a couple seeds in water until the green started
coming out. Took many days, probably more than a week or two. The
transplant failed.

Presoaking is really a treatment more for plants with hard seeds (and they
often need to be nicked or clipped, too). Big seeds, like most of the peas
and beans, are something I prefer not to pre-soak , though I'll put them on a
screen over a cool mist vaporizer or the like -- big seeds often don't take up
liquid water immediately, which can lead to cracked cotyledons and even
broken embryos as the water is absorbed more rapidly in one spot than another.
Seeds soaked as long as you did often die because the reserves are exhausted
by lack of oxygen, and the initial rootlets produced are not properly equipped
to take up soil water when you try to transplant.

Sand is the #1 gold standard germination medium in seed laboratories. Though
many, many tests are run on substrates like rolled towels or kimpack, when
there's a problem to figure out, or when you're thinking of switching suppliers
to a different manufacturer of towels or kimpack, you run comparisons
on the new toweling or kimpack vs. sand.

The stuff you want is just the coarse freshwater contractor's sand used
in making concrete or putting in sandboxes for kids. In fact, the sand
we used to buy for the seed lab came in bags labeled "play sand". (I always
wondered why we didn't get "work sand" g.)