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Re: Corydalis

I'm by no means an expert on the genus Duncan, but I do love most of them
that I've grown. I must beg to differ with you on the tubers. Some species
do form tubers, others roots. They are highly variable. Some are winter
annuals (technically biennials or monocarps I suppose) and some are
perennial. Many of the annual species are weedy and reseed terribly. The
perennial species, especially the tuberous ones, form large colonies. 

The tuberous rooted species are easily propagated by division if you can
obtain parent plants. Here in the US I've had trouble finding many of them.
The hybrids must be propagated by division as they will not come true from
seed. The problem is that some nurseries are selling seed grown versions of
the hybrids that are inferior. Do be careful in making purchases. 

Alternatively, the species may be propagated from seed. Seeds of most of the
species are either short-lived, or go into deep dormancy if not sown fairly
fresh from the plant. Seedlings will appear from freshly sown seed either in
the autumn of the same year or the following spring if sown out doors. If
sown indoors, they may need to be subjected to cold to induce germination. 

If all you can obtain is older seed, sow it anyway and give it alternating
cycles of warmth and cold. I've had good luck by using oscillating
temperatures. IE. - put the dry stored seeds in the refrigerator and bring
them out to room temperature for a few hours every three days or so for a
few hours and then return them to the fridge. Extend the warm period
gradually to simulate the warm up of spring. If this doesn't work for you in
a few weeks, leave them warm for three months or so and repeat the process.
Keep trying. It may take a year or more, but if the seeds are good they will
eventually germinate. If this sounds like too much work, just sow the seeds
in a pot, cover with grit and put them outside in a protected area, keep
watered and wait. Usually they will germinate eventually. I've had them
germinate outdoors after two years in pots. 

Be wary of the following species - they are weedy reseeders: C. sempervirens
(Rock Harlequin), C. lutea (Golden Fumitory)and C. flavula. There are
undoubtedly others but I've been lucky enough not to get a hold of them.

Grow well,
Amber

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Amber & Wayman Hearn                    jadare@accessus.net
Whippoorwill Creek Nursery              USDA Z-5
943 Foxville Road                       mintemp = -15F/maxtemp = 102F
Kell, IL 62853
618-822-6000
Our catalog is finally up - http://www.wcn.simplenet.com/Welcome/welcome.htm
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