Hi petunia! I don't know if I can be of much help, other than to say that I have very good results with winter sowing my asters. I am not at all fussy about coverage, light, temps, etc. That's why I never had good results with indoor sowing. Now I just throw the seeds in a container in potting mix, put the container outside, and forget about it till the seeds sprout.

Good luck! They are such beautiful flowers!
:)
Dee

Here is a link that might be useful: winter sowing FAQs

Thanks for the advice-I will give winter sowing a try. However, in the meantime I got thinking, and tried the "coffee filter and baggie" method of germinating that's described elsewhere on these forums.
Talk about instant results--in perhaps 48 hours, a number of seeds sprouted for me-something I've not been able to achieve otherwise. So last night I carefully planted over a dozen tiny, tiny sprouts. We'll see what happens.

Will also try some winter sowing and see how that compares.