----- Original Message -----
From: "Chris Hogg"
Newsgroups: uk.rec.gardening
Sent: Thursday, July 28, 2011 3:58 PM
Subject: Another Stipa question: stratifying seeds in the fridge/freezer


I want to sow some of my Stipa pulcherrima seeds (see earlier post). I
know from past experience that if sown now, they won't germinate until
next spring, implying they need a cold spell to trigger the process,
i.e. stratification. I would like to speed it up, and intend putting
the potted seed into either the fridge at say +4 deg. c. or in the
freezer at -18 deg. c., probably both as I have quite a lot of seed.
But does anyone know which is most likely to be successful, and how
long should I leave them in there?

I stratify a number of wildflower species and find that alternating them
(i.e. a couple of days in the freezer then three or four days in the fridge)
for a period of 6 weeks is the best method. Some species e.g. Primula
scotica usually respond within 3 weeks, whereas Primula veris and P.
vulgaris will give partial germination. These seeds should be given another
stratification treatment once any seedlings have been pricked out.

HTH

Phil