On 10/08/2012 00:27, David Hare-Scott wrote:
Kay Lancaster wrote:
Treat clay soils with respect... they're difficult to grow on.

yes indeed.

D

A commonly held and vastly mistaken view, IMHO. Difficult to work
maybe. But they are not difficult to grow on at all, if you keep to a
couple of simple rules. Firstly, never try to plant anything when they

I, too, have been growing on clay for about 40 years now... first the clay
subsoil that was all the builders left when they stripped the top soil
and sold it at my childhood home in Iowa, and now out here in Oregon --
both yellow clays, though the Oregon clay is calcium poor, rocky and
nearly free of worms (there are no native worms out here), so it
compacts easily and often requires mechanical aeration-- the Iowa soil
did not require much mechanical aeration and was calcium rich.

I still say it's a difficult soil to learn to grow on. It's hard to
work, and as one who was late to learn about shovel polishing of holes,
it can be unsuccessful just due to hole-digging technique. In fact,
the experience of trying to garden in my childhood home had really pushed
me away from the idea of ever trying to garden. It wasn't until I moved
to an area with a lovely, deep prairie topsoil that gardening became fun.
There, I could stand barefoot on bare soil and wiggle my feet a bit and
dig myself in ankle deep, the soil was that friable and loose. Stick a plant
in the ground and it grew.

But clay presents difficulties to most gardeners that a more balanced soil
does not... especially in the absence of good soil aeration. It can be
particularly tricky because of its cationic exchange properties... it
serves as an excellent buffer until it buffers no more.

Though clay holds soil moisture well, it's often not as available to the
plants as water in sandy soils, e.g.: http://ag.arizona.edu/turf/tips1095.html
which is a special problem in drought. And in comparing plant hardiness
in the soils in Iowa (USDA zone 5), I saw no real difference in frost
protection in clay vs. an organic loam: slope had a much larger effect.

David is, I believe, gardening on arid land clay in S. California;
a friend put her lawn in the front of the house in with (literally) pick and
shovel. When I lived there, my veggies were grown in raised beds to avoid
the salinized clay my house was built on (a failed orange grove).

Kay