are perennial favorites in the flower garden. Few herbaceous plants
can rival them for floral display and foliage. Their exquisite,
large blossoms, often fragrant, make excellent cut flowers and the
foliage provides a background for annuals or other perennials.
Two types of peonies are generally grown in the home landscape,
Paeonia spp. hybrids (garden peony) and Paeonia suffruticosa
following information pertains to Paeonia hybrids. Peonies
are classified according to flower form. All peonies have five or
more large outer petals called guard petals and a center of stamens
or modified stamens. Single forms have centers of pollen-bearing
stamens. Centers of semi-double forms consist of broad petals intermingled
with pollen-bearing stamens. Double types have dense centers of
only broad petals (transformed stamens). The anemone form, often
included in the semi-double category, may have more than one row
of guard petals encircling a center of thin, petal-like structures.
Japanese types are similar to anemones but have staminodes (stamens
that do not produce pollen) in their centers. Flowering usually
lasts one week in late spring to early summer. By selecting and
planting early, mid- and late-season bloomers, flowering may be
extended for six weeks. Flower color may be any except blue.
grow from two to four feet in height. Support is often required
for tall, double hybrids. Peonies thrive in sunny locations and
well-drained soils, tolerating a wide range of soil types. Best
growth is in soil with a pH range of 6.5 to 7.5, deep and rich in
organic matter. They are hardy from zone 8 to zone 2, with some
Planting, transplanting and dividing peonies are best done in early
fall but may be done in spring as soon as soils are workable. Each
plant requires an area about three feet in diameter. Dig a generous
hole, large enough to accommodate the roots and incorporate aged
organic matter in the bottom. Place the peony in the prepared hole
so that the eyes (small, red-colored buds) are one to two inches
below the soil's surface. Backfill and water well.
may be left undisturbed for many years. A decline in flower production
usually indicates overcrowding and the need for division. Carefully
lift the clump and wash away the soil to expose the eyes. Using
a clean, sharp tool, divide the clump into sections, each with three
to five eyes and good roots. Replant immediately.
have few pests or problems. The most frequently occurring pests
are botrytis blight and leaf blotch, both fungal diseases. Especially
prevalent during wet springs, botrytis affects leaves, stems and
flowers. Spots appear on leaves, stems soften and decay and flowers
either rot or buds blacken and fail to open. Prompt removal of infected
material and a thorough fall cleanup are essential for control.
Leaf blotch develops during warm, moist weather. Glossy, dark purple
spots form on the upper surfaces of leaves. Again, removal of infected
leaves and good fall cleanup are necessary for control. Avoid overhead
Other fungal diseases include Phytophthora blight and Verticillium
wilt. These are soil-borne fungi with no cure other than destroying
infected plants. Do not replant in diseased soil.
only insect pests of any consequence on peonies are scales. Scales
are seen on stalks and leaf bases in late summer and overwinter
on the below-ground portion of stalks. See GreenShare
Factsheet on scales for control recommendations. The presence
of ants on peony blossoms is neither beneficial nor harmful to the
plants--they are simply attracted to the sugary liquid secreted
by flower buds.
Failure to bloom may be the result of any of these factors:
planting too deeply
* immature plants
* excess nitrogen
* inadequate sunlight
* phosphorus and/or potassium deficiency
* insect or disease problems
* competition from roots of nearby plants
* late freezes
from Hope Weber, Ohio State University Extension, 2000