What is the generally rule of thumb (if there is one) for transplanting perennials? I have a bunch of hostas to divide and transplant. I could wait until spring, but wondering how late into fall I could get away with it.
I live in Vermont, Plant Hardiness Zone 5a/5b. I am mostly talking about hostas, lillies and other hardy plants.
As long as the ground isn't frozen, herbaceous plants that are solidly hardy in your area can still be transplanted. Plant at the normal (proper) depth, and mulch if you can.
I like to do it after the tops start dying off, but before I cut them. It kind of gives them a 'handle' and I don't have to worry about hurting them, because they're coming off soon.
Try to get a big root ball, for minimum stress. Mulching after planting can help keep the root ball from heaving out during periodic freezes. This can also happen to established perennials, but is more common when they're newly planted. Tamping well after planting helps a lot also.
