Seed germination temperature

Mon, 18 Oct 2010 11:26:09 PDT
Can anyone comment on the need for lowered temperatures at germination time
for Cape bulbs?  These have included multiple species of romulea,
geissorhiza, morea and lachenalia, for which zero germination has occurred.
I've raised seed such as these before for many years but this year, using
seed from a well-known South African source, the germination rate has been
zero. I will also add that for watsonia and non-bulbous species germination
has been excellent to fair. My concerns here relate only to the bulbous

As an example, for lachenalias I usually start in early September because
the early start and the winter temperatures here often gets them in bloom by
late spring in their first year. They are always fast and prolific
germinators, so the performance to date has been surprising. Could the
nighttime temperature be the cause? This year has been unusual with cooler
than normal daytime and higher than normal nighttime temperatures in
September and, so far, October. I have recently been placing a few of the
flats in a refrigerator during the night to encourage germination and am
hoping to see some signs of life. So far, none, but it has only been a few

If there are suggestions I'd like to hear. Thanks.  

Andrew Wilson
San Diego

More information about the pbs mailing list