3 tree peony answer
James Waddick (Tue, 03 Aug 2004 15:36:48 PDT)

The recent threads on tree peonies prompt me to ask three questions:
Dear Jim McK et al;

The topic of tree peonies is getting a bit far afield, but
I'll answer briefly with my experience and opinion.

They should be dug in fall as they go dormant. In your area
I'd guess after Oct 1. Their own roots will be far ranging and deep.
Use a saw or axe (you'll need them) to divide the crown (dust with
fungicide and or rooting hormone with fungicide) and cut them back to
healthy wood. Plant in light shade or where they will get a couple
hours full sun. Water well. They should recover in a year or two. Try
to do this on a cool day and be prepared for a lot of work.

There is some debate, but my opinion is to remove the
lactiflora under stock as soon as the tree peony has made its own
roots. The lactiflora root is a temporary nurse graft and will
interfere with long term health of the tree peony. Removing an old
rotting lactiflora root from an old peony is a major pain and a real
blow to the tree peony. Get rid of it ASAP. Tree peonies always do
better on their own roots.

Not all cvs are acceptable. This may be self sown seedling
and be a poor bloomer. I have a seedling that has made a single bloom
in ten years. I keep thinking its got to do better one of these
years. Getting named cultivars gives you a better chance of getting a
good blooming plant. Hybridizers tend to toss these poor bloomers,
unless it has exceptional (infrequent) flowers and then would be
sold/distributed as a breeder's plant.
But then you might also check the soil pH and alter
accordingly. Fertilize well. Thin out old wood. You might reduce it
to no more than 3 healthy stems. Mulch might help too.

Best Jim W.

--
Dr. James W. Waddick
8871 NW Brostrom Rd.
Kansas City Missouri 64152-2711
USA
Ph. 816-746-1949
E-fax 419-781-8594

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