I have some old white hellebores that I acquired years ago. They've been in the same spot since I got them. I think the root system of a nearby barberry is affecting their vigor as they didn't bloom this year or get as big as they used to. I'm going to be freeing up some space nearby in the fall and was wondering if that would be a good time to move them. The soil composition shouldn't change (although I might amend the soil a bit with compost) and the light exposure should be about the same.
