
by Mitzi
Davis
Colorado State University Cooperative Extension
Master Gardener
Larimer County
People remember peonies as the “cemetery”
flower. Peonies were planted at gravesites because they bloom around Memorial
Day and live and bloom for many years without much care. The peony roots that
Samuel Wade brought with him to Colorado in 1881 inspired him to submit the
Latin name for peony as a town name. The post office wouldn’t allow the
extra vowel, so Paeonia became Paonia. Some of Wade’s
original stock still grows in the town park—a testament to the longevity
of the plants.
There are about 30 species of peonies, all native to the Northern hemisphere.
Peonies are found in the wild in Siberia, Mongolia and north China and on the
lower slopes of the Himalayas, from Afghanistan to southern Tibet. Peonies are
also native to Caucasus – Georgia, Armenia, Azerbyjan and Turkey, Syria
and Lebanon. These parts of the world have climates similar to Colorado.
China has been cultivating and breeding peonies for over 1,500 years, mostly
using the roots for medicinal purposes. European and American gardeners are
more interested in the large, fragrant flowers that bloom each spring. Flower
color ranges from white and ivory to pink, magenta, red, coral and yellow. There
are two types of peonies—herbaceous (foliage dies to the ground every
winter) and “tree” peonies, which are actually deciduous shrubs,
not trees. Herbaceous peonies grow two to three feet tall and spread three to
four feet. Tree peonies grow to a height of four to five feet. “Rock garden”
peonies only grow 12-18” tall. They are very hardy, bloom earlier than
other peonies and have fern-like leaves. In 1948, Mr. Toichi Itoh of Japan successfully
crossed the herbaceous and tree peony. These hybrids are known as Itoh or Intersectional
Hybrids.
Fall planting is best for peonies but you don’t often find bare root plants
available for sale locally and must order them from a catalog or on-line sources.
Buy divisions with three to five eyes (buds). After planting, peonies may take
three years to bloom, but they will mature faster than divisions with only one
or two eyes. Peonies do not like heavy, clay soil, but don’t mind our
altitude or dry climate—they are quite drought tolerant after establishment.
Peonies prefer fertile, loam soil with good drainage. Amend the soil with compost,
well rotted manure, mulched leaves or bark to improve drainage and organic matter.
Take time to improve the soil, as the peonies will be in the same spot for years.
They won’t need dividing unless you are planning on moving them to a new
location.
Peonies do best with six hours of full sun and afternoon shade. The shade helps
protect the flowers from fading too quickly. To plant, dig a hole 12”
to 18” deep and 12” wide. Mound a cone of soil in the center of
the hole and drape the roots over the cone. Make sure the tips of the eyes (swollen
pink or reddish buds) are only one to two inches below the surface. The most
common reason for peonies failing to bloom is being planted too deeply. Firm
the soil around the roots, eliminate air pockets and water thoroughly. Water
the new peonies deeply every two weeks and water in the winter if there is little
moisture from snowfall. Use a loose mulch like pine boughs to protect new shoots
from late frosts next spring.
Apply a low nitrogen fertilizer (e.g. 5-10-5 or 5-10-10) in the spring when
the stems are two to three inches high. Use a fungicide when the plants emerge
in the spring if Botrytis blight or leaf splotch, both fungal diseases, becomes
a problem. Cut the herbaceous plants to the ground in the fall and discard the
old tops and stems. Do not cut tree peonies to the ground – they just
drop their leaves in the fall. Irrigate with a drip or soaker system and avoid
overhead watering.
Peonies make great cut flowers with their showy blossoms, long stems and wonderful
fragrance. Even the seed heads can be used in dried arrangements. They are also
a useful landscape plant in a mixed border. Their attractive foliage makes a
great backdrop to later blooming perennials. And no, peonies don’t need
ants to open their blooms! The ants are eating the sweet sap from the blossoms,
or if there are aphids on the plants, the ants are eating the honeydew from
the aphids.
For more information on peonies, visit planttalk.org and read topic #1042,
“Peony.”
The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.
Gardening and Insect Fact Sheets are available on-line by clicking HERE.
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