Donna,
I don't let most of my seedlings get very big. I usually pull them once I see they're not going to be interesting. I will keep an eye on my streaked hostas this fall and see if there's any seeds I can share with you. Fickle Blue Genes usually has seeds. Another plant that seems to seed itself in my gardens is coral bells. I'm not even sure where the seeds are on these plants, but there's two big ones in my yard that I never planted!
