The only faults that I find in tree peonies are that they require a permanent location(it is very hard to move a mature tree peony) and their bloom season is very short. You wait a year and can enjoy the flowers only for a brief period of time. I think that is why people want to protect their tree peony blooms. But like Liz said, when you see them in bloom, you tend to forget all the hassle and wait. Esp. if the tree blooms in a good stretch of favorable weather, it is spectacular.
If you want instant gratification, it is best to buy a grafted tree peony with at least 3-4 stems of growth and has started to develop their own roots. You will most likely get flowers the following spring. If you buy a small tree (1-2 years grafted), it may take a few years to bloom though it is alot cheaper. The time it takes the tree peony to bloom from grafted is 4-5 years. Some that are vigorous can bloom in year 3 but I don't know those varieties. It takes years to get it to blooming size so hence the higher cost for a more mature tree.
@csandt, do you know Ken's Gardens in Smoketown in Lancaster? They do carry potted tree peonies for sale in spring. These are Japanese tree peonies that are sold by color. This past spring, they offered red, orange, yellow, pink and purple colored tree peonies. If names of varieties are not important to you, these tree peonies are a great deal. They are very reasonably priced at $39.99 a tree and they usually have a few buds. If you get them on Customer Appreciation Days, you will get 20% discount (but the buds have already finished blooming). I wish I found them before I ordered a bunch from places that I shouldn't. Now, I am out of space to plant any more tree peonies. If I have more space, I would like to get the orange one from them. I think it maybe Kinkaku.
