Gee, sounds like you're ready to try your own version of hugelkultur? Just with a different type of rotting "logs?"
Oops, maybe shouldn't be giving you ideas...........
Getting back to those Columbines, I know you have lots of seeds, but would you be interested in some of the dwarf Columbine seeds I have? I really like them; they make a nice little compact clump with pretty little lavender-blue and white flowers.
