Does anyone know of a source for the above. I am looking for pre-chilled Echinacea "White Swan" and understand that there are some seed companies that offer this and other species for sale.
I have never heard of that, but if I did I would not believe it. My understanding is that stratifying, or what might be called pre-chilling, must be accomplished with the seed being damp, and with the seed being planted without being allowed to dry out, after stratifying. I just have not heard of "dry" chilling of seeds. Al
It may very well be that the companies which offer pre-chilled seed do exactly what you describe. I only know, from talking with a local commercial grower, that such seed can be purchased and that germination is improved.
prhart - you can effectively stratify White Swan (or any other) Echinacea seed yourself very easily by winter sowing the seeds. Check out the Winter Sowing forum here on GardenWeb and read the FAQs. I'm actually summer sowing White Swan Echinacea from commercial seeds at the moment and they sprouted in just 7 days. Germination appears to be about 60% so far but I expect more will sprout in the days ahead.
I prepared a recycled milk jug with drainage holes, filled the lower half with growing medium, moistened it and sprinkled the seeds on the surface. I did not cover the seeds. Stuck a label in the jug, closed it with duct tape and set it in the shade on my breezeway. The seeds were Burpee, bought at a discount outlet for 50% off.
prhart - there's a link to the Winter Sowing forum on the Growing from Seed page. Just scroll across the row of Related Forums near the top of the page.