If you don't stake peonies with large double flowers and weak stems they will flop,also rain will cause them to be weighed down even more.If you don't want to stake you are better off with varieties with strong stems which support the flowers.

I have both kinds of peonies. I must say, after my initial love of the singles, I'm back to preferring a full double bloom. They do require staking, though.

Here are pics of some of my peonies (none staked) after 1 inch of rain and wind on Monday (5/17)-
first 2 pics are singles "Doreen" and "Bowl of Beauty"; the 3 &4 pics are doubles "Duchesse de Nemours" and "Felix Crousse". The Duchesse and Felix are still on the ground, except for the stems that grew thru the chain link fence. I'm wondering if a cylindrical cage of fencing - spaced like chain link - with even the top covered with fencing -would be a great support if placed over the plant early in the season?

thanks for the input--on the HIdden Springs site, they had a section of peonies listed as "award winning" which appears to me to include double flowers that you don't need to stake. Am I understanding that correctly?

If so, maybe I should go with those.

Well, I'm certainly no expert, and all my peonies are quite young and not fully-formed to their mature "bushiness" - which may help the blooms with support. But IMO every double needs support in my windy growing conditions. If the doubles were sheltered, that would help. But rain flops even all my singles to the ground temporarily without support. But the doubles stay there! I'd post a list of what you're considering and people with experience with those varieties could tell you if they need staking.

Award winning means just that. They won an American Peony Society award. Has no reflection on if they need staking or not. Most of the early award winners were ones from the cut flower trade so they had long stems and large flowers. Guaranteed to flop.

I have many, many plants and cultivars. I stake all with the single or double rings. I leave them in the ground all year. They don't show when the peony is leafed out and after I cut them back in the late fall, I'm really not in the garden that much as far as "showing the garden to friends". If the plants produce blooms like I want them to, the plant gets too heavy and falls over from wind/rain without staking. Not a big job and saved a lot of nice blooms. I stake all plants. Good luck.