The Best Environment for Peonies

Soil

• Garden peonies tolerate a range of soil types but prefer soils to be loose and drain well. When planting garden peonies, usually in fall, dig a hole big enough to fit the root ball and completely bury the eyes, which are the small red buds on the root ball. Layer organic matter like compost in the bottom before placing the plant and filling. Tree peonies enjoy similar conditions and require amendment if soil is poor. They also prefer to be planted away from the roots of other plants.

Water

• When planted in good soil, both tree and garden peonies can withstand periods of drought, but they prefer to be consistently moist. However, Cornell University's Horticulture Diagnostic Laboratory advocates giving them a consistent water supply from the time they come up in spring until they die back in fall. To do this, check soil moisture consistently and apply a thorough soaking whenever soil is completely dry. Allow it to dry again before the next soaking.

Light

• Peonies of both types like a lot of sunlight. Where possible, plant in full sun, because peonies planted in shade will not bloom as well and will be significantly more susceptible to disease. Tree peonies appreciate some shading from strong sunlight, which you can provide by planting near enough to trees or buildings to catch afternoon shadows. Peonies that aren’t getting enough light may be transplanted, though garden peonies handle transplanting better than tree peonies.

Fertilization

• When planting peonies, to dig a hole deep enough to add a foot-deep layer of amended soil beneath the root ball. This could mean garden loam mixed with bonemeal at a rate of 1 1/2 cups per bushel, loam mixed with superphosphate at a rate of 1/2 cup per bushel, or pure compost. Three to four years after planting, you may apply a slow-release fertilizer in late summer, but not more than recommended on the package or else flowering might slow.