Peonies make a beautiful addition to the home garden and landscape! They add beauty with their wide variety of colors, shapes, and sizes of blooms as well as their wonderful fragrance. If planted correctly, peonies can last a long time in the garden from 50 to as much as 80 years. If you would like to plant peonies in your home landscape, fall is a good time to plant, so here are a few tips for planting perfect peonies.
Types & Cultivars:
There are three types of peonies for gardeners to consider for planting in the Kentucky garden.
- Herbaceous/garden peonies are herbaceous perennials that reach 20 to 36 inches in height. This type is the most common peony used and is the least expensive compared to other peonies.
- Tree peonies have woody stems that do not die back to the ground. They are a medium-sized shrub that reaches no more than 4 to 5 feet in height. Tree peonies are slow growing, so it may take four or more years to bloom well.
- Intersectional peonies are a hybrid type produced by crossing a herbaceous peony with a tree peony. These peonies get the best of both worlds. They possess the hardiness of the herbaceous peonies with the attractive flowers and foliage of the tree peonies. Itoh peonies, named by the first hybridizer Toichi Itoh, are a type of intersectional peony.
When purchasing peonies, purchase tubers from a reputable nursery catalog or from a reliable local garden center in the area. It is a good idea to buy and shop early to guarantee the best selection and variety desired. Inspect tubers for rots before planting.
To guarantee an extended blooming display, choose a mixture of early to mid- to late-season peony varieties to plant. By buying plants with different blooming seasons, gardeners are guaranteed 6 total weeks of peony blooms to enjoy. Make sure to read plant descriptions in catalogs and watch labels in garden centers to find this information.
Here are some noteworthy peony cultivars of different types captured by fellow Kentucky gardeners:
Best Location for Peonies: Plant peonies in well-drained soil. Wet locations promote root rot problems that will cause damage to future plants. If soil does not drain well, build and install raised beds to improve soil drainage. Before planting, incorporate 2 to 4 inches of rich compost or well-aged manure to the planting area for added organic content. Peonies perform best in full sun with 6 to 8 hours of sunlight. Some tree type peonies will benefit from a little bit of shade or filtered sun in the afternoon to help their bloom color last longer.
When to Plant: Fall is the absolute best time to plant peonies. September and October are ideal months for planting.
Planting Procedures: In the ideal location, next prepare the site for planting. Dig the planting hole to a depth of 12 to 18 inches and a width of 18 inches wide. Remove soil from the planting hole and break up any clods that come to the surface.
For herbaceous peonies, plant tubers 1 to 2 inches below the soil level with the eyes facing upwards and the roots facing down. Plant tree peonies below the graft union with 4 to 5 inches of soil covering the graft. The graft is noticeable by the ridge on the stem and the difference in bark texture. This deep planting helps the graft develop its own root system.
A common reason that peonies do not bloom is due to gardeners planting the tubers too deep. Take extra precautions to ensure the correct depth for the peony being grown. Use a measuring tape or yardstick, if needed.
Space multiple plants 3 to 4 feet apart in the row. Once in place, work the soil around the fleshy roots and fill the planting hole back with remaining soil. Water plants thoroughly.
Other Maintenance Tips: Keep soil moist when the weather is dry. Water is also very important during bud formation and flowering. Mulch newly planted plants with a 2 to 3 inch layer of organic mulch such as clean straw, pine needles, or bark mulch in late fall to keep plants from heaving in and out of the soil. The mulch also deters weeds from germinating and conserves soil moisture.
When new shots begin to form in the spring, place a stake like a tomato cage or a flower stake over plants to hold blooms up after a heavy rainfall or harmful winds. Fertilize plants in early spring when growth is 12 inches tall and immediately after flowering. It is best to lightly cultivate around the crown of the plant with ¼ cup of 5-10-5 fertilizer and water it in.
For more information about planting peonies this fall or growing peonies in the garden, contact the Warren County Extension Office at (270) 842-1681.
Kristin G. Hildabrand
Warren County Extension Agent for Horticulture