| Dear Cathy;
Your tree peony
didn't 'revert', but the nurse root has taken over. There's still hope
as long as any of the tree peony still exists. Here's a repeat of an answer
I provided on an earlier FAQ:
1. In the fall dig the entire plant. Locate the
nurse root-usually thick and red-brown, the TP roots will be white and
thinner. Often the graft is marked by a major swelling in the nurse root.
2. If the TP has good roots of its own proceed
in #3. If you see no TP roots and the graft was not planted deeply enough
do the following:
a: remove all the nurse root
suckers close to the nurse root (use a sharp knife).
b: cut the nurse root by a
third or so
c: plant it deeper with the
graft union much deeper-at least 3 or 4 inches of the tp below soil level.
You can also make a slight scratch in the base of the tp and dust with
a rooting hormone.
d: wait a year or two and
follow #3 below
3. If the Tp has good roots - at least 2 or 3
roots 6 to 8 inches long, you should locate the graft union and remove
ALL of the nurse roots. Usually the nurse roots are fairly fleshy, while
the base of the TP will be woody. Keep cutting the nurse root back until
you feel the resistance of the TP. BE VERY CAEFUL that you do not remove
the TP roots.
Replant so that the TP roots are about 3-4 inches
lower than before.Fertilize with 10-10-10 and keep well watered. Cut the
top growth of the tp to a few short stems.
This will remove all the nurse root suckers and
allow the TP to grow faster and stronger on its own roots.
DO NOT try this in the spring as it will surely
kill the plant, but cut off all herbaceous peony suckers and keep well
fertilized and watered until you can dig in the fall.
Best of luck and hope this helps.