You don't say whether they are fresh out of the pots or if they had been planted. The best published information recommends the tree peony be planted several inches deep so the herbaceous roots will nourish the tree peony graft but will be too deep to grow stems independently. The tree peony graft union will grow its own roots as the herbaceous roots die out. Some of the members on this forum are relatively experts with tree peonies and can shed more details.
