The seeds are extremely tiny. They can be sowed now. They take a while to get up to some size. I left them in the containers until Hurricane Irene none of them made it. But the Heuchura did. They need room, sow them sparingly in jugs.

It self-sows for me in Zone 8a so I think it would do very well wintersowed.

It self sows wildly for me, but I find it does better Fall sown than winter sown, with a warm moist period first. 8b

I have ws alchemilla with great success. There is limited self sowing of this plant in my flower beds.

Lady's Mantle is a great WSown plant. I just love it under and around my rose bushes. 2 years ago I planted a bunch out "HOS" and last summer was able to divide those teenagers into groupings around the yard.

I let the flower heads dry on the plant, cut the whole thing off and dry some more, then just crumble the whole thing into a plate and package up a mix of seed/chafe to sow. Finding that tiny seed is just impossible, and I've had great germination with this "Dried flower head crumble" way.

Thank you everyone for your advice. I'll give it try!