Peonies (Paeonia hybrids) are a bushy perennial best suited for cool climates where cold winter temperature will ensure blooms the following summer. Buds appear on the plant in spring as firm round spheres, often visited by ants attracted to the sweetness of the bud. Blooms, which open in late spring to early summer, may be white, purple, deep red, pink or yellow. Peonies can grow 20 to 36 inches tall.
Peonies are cold hardy in USDA zones 3 through 7. Newly planted peonies may not bloom for up to three years. Peonies do not need to be divided unless they become crowded. If a peony needs to be moved, do so in late summer or fall after dividing the root ball. Not all peonies are fragrant, including single bloom peonies and red peonies. Pink or white double peonies, like la France or Chestine Gowdy, are very fragrant varieties.
Choose a full sun location on the north side of your landscape that drains well and is away from trees or shrubs whose roots can interfere in the successful growth of peonies. Plant a single peony as an accent surrounded by shorter plants or ground cover, or plant an odd number of peonies, like three, five or seven, for visual impact. When planting multiple peonies, set them 3 to 5 feet apart.
Plant peonies in late summer or early fall, a time when most peonies grow their roots. Dig the hole about 12 inches deep and 18 inches wide to loosen the soil. Mix two to three large handfuls of organic matter, like leaf mold, into the soil removed from the hole. Backfill the hole to about 2 inches from ground level, and then place the peony so the eyes (growth buds on the peony root) are pointing up. The peony root should be no more than 2 inches below ground level. Finish backfilling the hole.
After planting, water the peony and do not apply mulch. Continue to water every seven to 10 days until the first hard freeze if there is no rainfall. In subsequent years, cut the foliage to the ground in late fall, a step taken to reduce potential of fungal disease developing during the winter. Fertilizer is not needed. After the first hard frost, autumn leaves or leaf mold can be spread over the perimeter of the plant (not on top of clipped stems). The leaves will decay to provide natural nutrients to the peony roots.