TOW seed dormancy - Alstroemeria
Diane Whitehead (Thu, 15 Jan 2004 20:28:52 PST)

I am curious as to why Roy is having success chilling Alstroemeria
seed as his first treatment. Does he live in a very warm place where
the seeds are warm for a while before he sows them? He mentions
soaking them for a day and then chilling them. Chilling is relative,
though. I consider 18 C (~ 65 F) to be warm, but someone in Texas or
Australia might consider it cool.

I follow the temperature and timing that Deno recommends for
Alstroemeria: 4 weeks warm (i.e. about 18 C in the daytime), followed
by cold (outside, so between 5 and 10 C). It has worked for all the
seeds I have sown, though germination times vary a lot.

I recently bought 12 packets from Flores and Watson. Two lots of the
seeds are from the current collecting season, and the rest are old
seeds being sold off at a bargain. I sowed them as usual, in plastic
ziplock bags of soilless mix, and put them in the dining room which
is kept at a daytime temperature warm enough not to need a heavy
sweater. Normally I wouldn't have looked at them until a month was
up, at which point I would put them outside in a coldframe to
germinate. Fortunately we had guests for dinner which meant I had to
move the seed bags. I was surprised by active germination. Both the
old seed and this year's seed germinated, all between 10 and 15 days,
except for the two lots of A. crispata and one of pseudospathulata
which haven't germinated yet in 30 days.

I don't understand what has happened. I have always sown
alstroemeria seeds at the same time, midwinter, (December and
January) when exchange seed arrives. Perhaps the storage technique
of John Watson's English partner, Martyn Cheese, has made the
difference. Seed freshness does not seem to be an issue, as both his
old and new seed germinated quickly, and both old and new haven't
germinated yet.

I've calculated days to germination of seed from other sources (each
number represents one package of species seed).

Archibald: 16, 18
Flores and Watson (in 2001): 43, 74
Alpine Garden Society: 18, 35, 64, 96, 120, 165, 183
North American Rock Garden Society: 50, 50, 50, 73, 301
Scottish Rock Garden Club: 21, 56, 56

It seems that, in general, seed from the big seed exchanges takes
longer to germinate.

The species I recently bought from Flores and Watson are mostly ones
I do not already have, so I can't compare them with seed exchange
seed. Just one duplicate: AGS 2001 A. pseudospathulata germinated in
35 days, and F & W this year's seed hasn't germinated yet in 30.

--
Diane Whitehead Victoria, British Columbia, Canada
maritime zone 8
cool mediterranean climate (dry summer, rainy winter - 68 cm annually)
sandy soil