It looks like it rarely goes below 32f here, but will be prepared in case. More so than a freeze is my concern for nights under 40f, as those seem potentially more frequent than I'm used to. For anyone else that comes across this, it looks like Im in Zone 10A, with 9B close by. I'm not sure what the root stock is on this tree, but it looks like it produced flowers last season, and the trunk is quite thick. From doing a little internet research, it looks like Valencia Pride are a little bit more cold hardy then a Glenn or some other similar varieties. Will keep this thread posted on the progress of this tree.

Gotsomerice, I would strongly suggest that you plant the peonies in as large a container as you can muster. The larger the container the more reduced the stress due to inconsistent watering. I planted one tree peony last fall in a 35 gallon pot. I am not sure what I was thinking at the time, I may have to hire a moving crane to get the plant out of my garage this spring and then back into the garage next fall. If you have some type of automatic drip irrigation system you could get by with smaller pots. I would think you should not use a pot smaller than 10 gallons. I understand that some people in California are able to force dormancy in some varieties of tree peonies without any chilling at all. They carefully remove each leaf from the plant which throws it into a pseudo-dormant state. When the plant begins to grow again it may bloom. I assume you would need to wait for the plant to set buds before you remove the leaves just as they would before frost kills the leaves here. I have never tried this since I live in a temperate area with a bad temperament. It is here that if you don't like the weather don't worry, it will change. I think they are forecasting 3°F tomorrow. Tree peonies are not too fussy about the soil they grow in. Almost any garden loam or potting soil that is near neutral in pH will keep it happy. What cultivars of tree peonies are you getting? Leon,

Tree peony and Itoh peony can grow in zone 9. If the leaves don't fall in autumn, you need to trim the leaves off to force dormancy for next year's flower. There are tree peonies, Itoh peonies and some herbaceous peonies growing in The Huntington Library, near Los Angeles. Herbaceous peony "maxima festiva" perform well in zone 8, not sure how it perform in zone 9.

Looking forward to it!