I have no doubt that Al's 400 hours is valid. When I researched commercial peony production as cutflowers for the "Cutflower Quarterly" years ago, that 400-hour number was probably a good part of the equation for successful flowering. But it's not that simple and I'm sure it's much more than just hours of chilling. The Sunset Western Garden Book (a source that I always reference) indicates that peonies are suitable for our zones here (14-17). Mostly, we do get the 400 hours and then some. Yet I have not seen one good one here. And I personally know dozens of people who have tried and mostly failed (including ice cube experimentors and the like). Yes, I do know a couple of people who are very excited that their 10-year-old peony in a pot has had one or two flowers the last couple of years. I had even heard of a lady in the Santa Ynez Valley that "had great peonies". When I tracked her down, she told me that "they come up in April, have a couple of blooms in May, and then die down in June". That was her "success". Much as with so many eastern perennials (including Hosta, Astilbe, Echinacea, Monarda, Phlox), I believe there is a combination of factors that make it difficult to impossible to succeed with these plants. The factors include soil quality, water quality and summer humidity. The Bay Area (also Zones 14-17) mostly has better soil and water conditions than we do in our Zones 14-17 here on the Central Coast and some gardeners, with lots of prep work, do have degrees of success. (There actually used to be a commercial peony cutflower grower in the Fremont area.) But So. Cal has even less agreeable conditions. Plus combine all those not-so-happy conditions with our snail populations. Again, if anyone in So. Cal has truly succeeded with herbaceous peonies, please chime in. Joe

I have planted several of them in various parts of my garden, and they have experienced benign neglect most of the time--no special winter treatment, fertilizer, etc. The soil here is a limestone soil and heavy clay for the most part. My plants are several years old now, and the largest is only about two feet tall. They were bare root when first obtained. All are in partial shade, two at the edges of informal planting areas under full-sized maple trees. One maple casts quite heavy shade, and that tree peony has remained quite small. The other maple tree casts dappled shade and is next to a neighbor's lawn which gets full sun all day; that one is probably the largest tree peony I have, and one of the youngest. That bed is slightly raised and mainly consists of organic matter. Another tree peony is in the center of an area of deep soil that used to be lawn. It did well initially and was larger than the others, but has suffered from the spring competition presented by a bleeding heart plant I established quite close to it. I have two on the berm of a small bank on the North side of my house; the one receiving the greater amount of sun is easily twice as large as the other one, even though they were planted at the same time. I have one in a shady place level with the ground that I had forgotten about--it is struggling a bit but still returns. Finally, one I planted in very poor soil with little preparation is still alive, but so far has not even flowered, and it certainly is not thriving. Therefore, I would say that they like a bit of a raised bed, or at least the organic matter you can put into one of those, and probably don't like wet feet or oxygen deprivation. I haven't done any special watering, but this is PA; we may get more rain than you. I have seen full grown tree peonies in the Hershey gardens. They were probably ten or so feet tall and looked a bit like broad, dwarfed trees with dark trunks. They were still sort of interesting after their spring bloom. I have also seen a few planted by gardeners in the area. They looked more like densely-leaved shrubs, from about five feet to eight feet in diameter. I think their leaf density could be partly because they were all in full sun, and also due to pruning. They all had a round shape. I have found a bit of judicious pruning can save problems. Apparently the little stalk that bears the previous season's flower dies, and can then be a source of fungus or other infection; that should be clipped off in early spring for that reason. Apparently Hershey had some fungus problems a few years ago with some of their old peony trees and they had to be removed. It can get quite humid here during the summer; possibly that was a factor. For that reason, though, you might want to see that your plants are not too crowded. All of my plants are protected from prevailing winter winds by my house, but there are a few not too far from where I live that do not have that sort of protection--although the owner might cover them in the winter; I haven't noticed for certain. A couple of my plants now usually have at least three large blossoms each spring. They are easily ruined by rain and don't last that long, but they are spectacularly beautiful, and I therefore am glad I have them; I look forward to them each spring.

You don't have to use a ring or hoop. You can simply use stakes that are just shorter than most of the tallest foliage and then tie the mass up to the stakes, arranging the leaves to cover the tie. I have seen some single stakes with a ring on them where the ring is open enough to scoop some of the stems and foliage into it to pull the mass upright and then the stake can be pushed into the ground. Some people even use small tomato cages and let the foliage grow through.

Are the stems smooth and green or green with red splotches or more brown and woody? Lucklein is right, tree peonies can easily grow that tall. If it has a woody stem that's the answer. I only have a few tree varieties but none of them need to be staked.... The stems do grow taller and scragglier if a herbaceous peony is in too much shade, though. Typically there will be a few tall, gangly stems and fewer blooms so not sure about yours since they seem to be blooming well. Maybe they're not way too shaded....A picture probably would be a lot of help!