Winter sowing geophytes
Jane McGary (Wed, 24 Dec 2008 15:19:28 PST)
Alani wrote,
One of my original attractions to geophytes was do a frustration with
difficult seeds. Without heat most seeds just seem to wait until spring and
natural warmth even in a cool greenhouse. Without even a cool greenhouse the
only one for here that comes to mind would be garlic chives. Not too
inspiring I know.
There is a vast literature on seed germination and the different
temperature cycles that individual genera and even species respond to
by germinating. Some geophytes germinate in fall as soon as they ahve
had a period of warm, dry storage and then get moisture, while others
need one or more multi-month periods of moist chilling (not freezing)
followed by warmth. In some cases (Cyclamen, for example), fresh
seeds germinate quite soon, but stored seeds can take several years
to do so. The most mysterious to me is Colchicum, in which something,
presumably temperature fluctuations, will trigger germination in
several species planted in different years within a week of one another.
I wrote a detailed article, also helpfully commented on by John
Lonsdale, that appeared about 2 years ago in the Rock Garden
Quarterly vol. 65 no. 3. It covers growing many genera of bulbs (not
tropical ones, which I don't grow) from seed. It's too long to put in
our PBS newsletter, but back issues can be purchased at http://www.nargs.org/
Jane McGary