Peonies are chameleons. Sensitive to light and temperature levels, they grow and bloom differently in different places. The color that growers in Alaska report a variety as blooming is only a general guide for me in South Carolina. Reports of bloom time--early, mid, late--are all over the place. Not because growers are bad at reporting accurately, but because in their fields, peonies are acting a certain way. And it's unique to their location. Even the information on which varieties will perform well is location- and climate-specific.
So what's a small-time peony fancier to do? If you want one, two, or half a dozen peonies in your flowerbeds, how will you get variety advice that works for you?
Your best bet, I'd say, is to find a local peony grower and pump her for information. Many flower farmers who aren't specifically peony growers also have a few rows of peonies and valuable growing data.
As of 2023, I'm growing 49 varieties of peony. Some of them are winners, a couple are really heartbreaking losers, but most are just content, productive citizens of my fields. In my product listings for peony roots and plants, I make sure to let you know whether the variety in question is something I have experience with or not. Sometimes, when I'm planting a new variety, I'll offer it to you as well, but know that it's something of a gamble.
I live and farm in upstate South Carolina, in a mild winter, hot and humid summer, USDA zone 7b climate. I have clay soil and temperatures that I've seen as low as 2 degrees, but usually stay at least 20+. The main challenge, perhaps, with choosing varieties for my area is the sudden, hot summer. We'll go along with a beautiful mild spring through March, April, and much of May, and then, suddenly, summer temperatures show up to stay until October. If there are buds on peony plants and that temperature shift happens, they may simply refuse to bloom. The progress toward opening halts. Eventually the bud turns brown from the weather and the petals drop.
For this reason, it's best to keep to earlier and mid-season varieties in a climate like mine. A variety that's known as a late bloomer may not bloom for you every year.
All of that is to say, if you live in a climate like mine, with soil like mine, here are (some of) my variety notes. If you live farther away, please take all of these recommendations in the knowledge of peonies' changeable nature. I'll note whether this is a variety recommended by Clemson University Cooperative Extension, as well as which are my top strong growers.