I have an established tree peony?

can i transplant it after it blooms, it's been established for about 4-5 years

I have an established tree peony?
The common rule is; peonies don't like to be moved. But 4-5 years is not terribly old, so the roots haven't dug very deep. I have moved tree peonies that age successfully. They took a year or so to re-establish, but the new locations were better for them so it was worth it. You may not have many blooms the first year after re-location, but they should be fine. Take as many roots as possible with them. GL.
Reply:I would 'root prune' (cut around the root ball you plan to move with a shovel - the larger area the better) now to stimulate root growth closer to the trunk, but wait to actually move it until after active growth -late summer or fall would be best. Keep it well watered after moving.