I think GMCPaul hit it pretty much dead on. I've done it, but had poor luck doing it. I wouldn't advise it.
Instead, I'd recommend you put them in a raised bed. Put down a few inches of gravel to separate ground from bed, then landscape fabric, and fill it with a peat/sand/hardwood mulch mixture. Make sure your shade is good and they will be beautiful for years.
Legality:
I don't know what state you are in, but here, transplanting wild into beds is completely legal. However, harvesting seed from roots you harvest is not.