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

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