The culture of the peony is relatively simple. The plant thrives in practically all types of garden soil, but grows best in a rich garden loam. The soil must be well drained and retain adequate moisture during the flowering season of the plant. The plants need plenty of sunlight. Peonies will not do well in shade or in low areas that become waterlogged. Peonies planted in shade are more subject to diseases than when in full sun.
Planting
herbaceous peonies
The best time
to plant, move and/or divide peonies is in the late summer-early fall, from
September 1 to October 15. This gives the plant time to establish roots before
the winter. Space plants 3 to 4 feet apart. Peonies are tolerant of slightly
acid soil, but if the soil pH is lower than 6.0, ground limestone will be needed.
Leafmold or compost may be added as soil amendments. If peat moss is used, the
soil pH should be adjusted to compensate for the increased acidity. A soil test
is recommended before planting peonies or adjusting soil pH.
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Dig a hole 1-1/2 to 2 feet across and 2 feet deep. Replace the soil in the bottom 1 foot of the hole with good garden loam, to which bonemeal or superphosphate (0-20-0) has been thoroughly mixed. Bonemeal may be added at a rate of one pound (1-1/2 cups) to each bushel of soil replaced in the hole. Superphosphate should be added at a rate of one-half pound (1/2 cup) per bushel of soil replaced in the bottom 12" of the hole, to prevent burning the roots. Place the peony root in the hole with the top of the eyes (sprouts) pointing up. The eyes should not be over two inches below the ground level when the peony is finally in place (See Figure 1.) Fill the hole with loose topsoil, working it in carefully around the roots. Water the peony root in well. |
For the first winter only, newly planted peonies should be mulched after the ground freezes. Sawdust, straw, evergreen boughs, or soil mounded up may be used as a mulch to prevent heaving by frost action. Remove mulch in spring before the new growth starts.
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Planting
tree peonies If the plant is small, make a hollow around the plant, filling in with soil as the plant grows. |
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Disease
Control
To reduce the
chance of disease, primarily Botrytis (a grayish-brown fungus on stems,
leaves, buds), spraying with a fungicide may be necessary. The first spraying
should be done just after the plants break through the ground. It should be
repeated when the plants are about half grown and again just before they bloom.
To prevent leaf spot they can also be sprayed several times after blooming.
Contact Cornell Cooperative Extension - Suffolk County for up-to-date fungicide
recommendations.
Fertilization
If the peony was
planted in properly enriched, fertile loam to start with, the plant should not
need additional fertilizer for 3 to 4 years. Over fertilized peonies will produce
foliage instead of flowers, so fertilize with discretion. The type of soil will
determine the need for additional fertilizer. Porous soils lose their fertility
more rapidly, as nutrients are leached out by rain. Keep all fertilizer away
from the crowns of the plants. Spread it over the area where the roots grow,
6 to 18" from the crown, and thoroughly scratch it into the soil. Apply fertilizer
in the fall. Use a commercial fertilizer, one which is not too high in nitrogen,
(20% superphosphate
is excellent) or an organic fertilizer like bonemeal.
Fall
Clean-Up
After September
the tops of herbaceous peonies should be cut to the ground. Never cut tree peonies
back to the ground, unless the stem is diseased, as the next year's growth starts
from the buds formed on the old wood. All foliage of both, herbaceous and tree
peonies, should be collected and destroyed or composted to prevent diseases.
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Digging
and Dividing (See Figure 3). Divide herbaceous peony plants in late September, after the stems have been cut off almost to the ground. Leave enough stem to handle the plant by. Use a spade, shovel, or spading fork to cut all around the plant as deep as the tool will go, about 6" from the outside of the plant, cutting away from the crown. Reverse the tool and go around the plant, loosening it by gently prying. Lift the plant out carefully. Wash the soil off with a hose so you can see the roots better. |
Use a sharp butcher's or hunting knife to cut all roots back to 4-8 inches, enabling you to see where they are joined to the crown. The best divisions come from the outside of a large plant. The roots should be joined to the crown at or near the base of the eyes. The new division should have 3 to 5 good eyes and several roots 4 to 6 inches long. Be sure all cut surfaces are smooth and clean. Cut out all rotted portions and destroy any diseased plants. Plant new divisions immediately.
Tree peonies do not divide as readily as herbaceous peonies. Older tree peonies can be divided when several branches appear off the main root system. Be sure that every top branch has a root on it before dividing.
Cultivation
Cultivation should
begin early in spring and continue often enough to keep the weeds down and the
soil aerated. It should continue until the fall. Applications of mulches can
be applied to reduce weeds and help retain soil moisture.
Watering
Peonies need an
even supply of water from the time they come up until they die back in the fall.
Give them a thorough soaking down to the bottom of the roots when it is a dry
season. Repeat when the soil is dry. This is important during the summer, as
well as, throughout the flowering period, as the plant is producing eyes for
next year’s growth.
Resource for information: Notes on Planting Herbaceous Peonies in NYS* and Notes on Care of Herbaceous and Tree Peonies *, The Cornell Plantations, Ithaca, NY, abp, 3/80.
For more information contact: Tom Kowalsick, Extension Educator - Horticulture, CCE - Suffolk County
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