One thing I know for sure, you are not likely to kill it whatever you do. I am thinking of trying to limit the spread of mine by replanting them in large pots from which I have removed the bottoms to see if they will prevent their limitedless spreading. I will still have to pull up seedlings.

Hi Mcube, I think you got this from me at a swap, sorry to have unleashed this monster on you! Hehe It's a beautiful monster though. Mine is trying to take over the side yard. I have no idea how I'm going to tame it ultimately. I might move a lot of it to a wilder part of the back yard and let it duke it out with the Pokeberry. :) Bill Cullina says you can prune the roots by circling with a spade. Not sure how well that works.

As for division, you don't have to dig out the whole clump though, it's easy to dig out divisions to pot up. This is one plant you don't have to wear kids gloves.

Terrene, Yea .. I did get this from you at a swap couple of yrs back. The clump is now atleast 5-6 times bigger and is taking over the bed. I love the plant though as it puts on a show in late summer.

Thanks for the tip. The clump is about to get a lot smaller tomorrow :)