I believe that peonies need their foliage all summer to feed the roots you plan to move. I would leave the foliage on until the frost gets it. Then I go out and cut, haul away all the foliage I trimmed off them to prevent any hidden problems coming back next year.

I would plan to move them in late summer, here that would be Sept. Gives them some time to settle in, leaves on still feeding them a bit, before we get fall rains started. I cover them with shredded leaves for protection from the rain washing all the dirt off.

Do dig out away from the plants as you start the uprooting. With older plants you find much larger roots than what you see in the stuff at stores. You can get closer with shovel when you see the actual size roots you are dealing with. They can snap easily, so don't pull too hard. But sometimes they just are too unwieldy to manage, so breakage does happen.

My mother's peonies have HUGE root balls. She has a real touch with peonies, treats them roughly in separating them because it is so hard to do, and they still come right back, bloom the next year. She is always digging them up to give some away, thinks hers are crowded. I am not that lucky with mine! Mine take longer to recover when moved, especially if I am nice to them!!

Good luck with your renovation next fall.

Wait till late August/early September, not just to feed the roots but also to give next years eyes time to form.

Here is a link that might be useful: More excellent info here

Thanks, will do!