Bareroot peonies purchased this time of year are best potted up in one gallon pots until the fall when they can be planted in the garden. Al

People want to buy peonies in spring, so that is when they are offered for sale to passing trade. Potted peonies are very common in spring but almost impossible to find at other times of the year, not good garden sense but good for shifting stock.

I know, they are really hard to resist at that price, I never can. I'll be there to check them out. Last year I bought some of the odd ones, was it Blue Lagoon? I think anyway, and they bloomed that spring. Very pretty flowers, & definitely worth the money. If you wait til the fall, it will be spring before you can hope for blooms anyway. When I buy them locally, I just pop them in the ground as soon as I can. I certainly don't count on them blooming that spring, & if they are very small it might even be the 3rd year. I have a couple this will be the 3rd year for, but that is mostly my fault because I mulched in the fall & they got planted deeper.

Peonies are always best planted in fall. With a reasonably sized plant you have a good chance of first year flowering! Please note that size alone itself does not say anything about quality, let alone if the variety is true to type. Buying potted peonies often leads to disappointments because they form very many thin roots on which they do not bloom. After planting in soil the root system needs to get massive again to produce flowers. Often this takes a few years and dissappointment is unfortunately the consequence, having lead to the untrue saying that peonies do not flower easily.
Therefore it is always best to buy your peonies from a good specialized peony grower who sells his plants in the natural digging and planting period: FALL.

Here is a link that might be useful: Peony information and catalogue of quality peonies