Posted: 03/07/2015 at 10:18
I don't know how you've treated it Deborah, but tree peonies are best planted in Autumn/Spring. They like good drainage, although I have seen them growing happily in clay, too much heat in the early days can hold them back and they won't establish. I'd hold off on the watering and mulch it, keep the mulch away from the main stem and leave it alone for a while. They can be slow to establish anyway, and if it's a grafted plant, it should be planted with the graft below soil level. Although hardy, they can be fickle in my experience especially when first planted.