Bulbs for Shade--TOW
Roy M. Sachs (Mon, 19 May 2003 11:50:18 PDT)

Did we specify how much shade? and where one lives? and how plants
do with morning sun only and afternoon shade?

In Davis, CA I grow as much as possible, including glads, watsonia,
freesia, Amaryllis belladonna, Hippeastrums, alstroemeria, etc., in
at least 30% shade (but we have 2x the irradiance of almost anyplace
in New Jersey, the Finger Lakes, NY, and many more spots I've lived
in the US). And I've been told by some nurserymen to go up to 50%
shade.

At one time in a problems course in horticulture we were able to show
that it wasn't the high light that killed most shade plants tested,
but the accompanying high heat of the leaves (we used water filters
to intercept infra-red wavelengths without seriously reducing
incident light).

At a Russian River location, which has irradiance about as high as in
Davis, I can grow many things in full sun and with high quality
inflorescences which do poorly in Davis. A good measure of shade
loving is how hydrangeas do; they do poorly in full sun in both Davis
and on the Russian river.