Germination
Jane McGary (Mon, 18 Feb 2013 09:04:34 PST)
Rachel Saunders of Silverhill Seeds wrote:
I always knew that Lapeirousia seeds needed to be aged for a year, but I did
not realise that almost all our bulb seed needed it. We harvest all our
seed of SW Cape bulbous species in the months of September - December. This
means that if you purchase them and sow them in your autumn, they are at
most a month old. And obviously this is too fresh. In nature the seeds do
lie in the heat for about 6 months before the cool weather of our autumn
sets in, and then I do think that a cold minimum temperature is important.
But obviously one needs heat first followed by cold.
I have noticed a similar result with seeds I collected in western
South America. They have germinated best when I kept them at room
temperature over the Northern Hemisphere summer and sowed them in the
following autumn.
In contrast, bulb seeds collected in the N. Hemisphere germinate best
here when sown in autumn of the same year. (Some non-bulbous plants I
grow for the rock garden, notably Brassicaceae, are immediate
germinators best sown in spring.)
Jane McGary
Portland, Oregon, USA