Garden Variety: Peonies, longtime garden favorites, require little care

Peonies are blooming now around the Lawrence area, and their colorful blossoms are an inspiration to add them (or more of them) to the garden. Peonies perform reliably for decades in the landscape with little care and are available in a variety of colors. They are longtime garden favorites that typically bloom in May to early June in Kansas and are often associated with Memorial Day.

The most common peonies are herbaceous perennial flowers that produce a clump of stems from the ground each spring. Stems grow to around 2 feet tall and have deep green leaves. Each blossom is produced at the top of a stem.

Tree peonies, however, grow to around 4 to 6 feet tall with a single woody stem. There are also intersectional peonies that are crosses between herbaceous and tree types. The benefit of this cross combines the reliability of the herbaceous peony with the broader range of flower colors found in tree types.

Classic peony varieties have flowers that are white and various shades of pink to red. Tree peonies and intersectional peonies have flowers that are white and various shades of pink, red, yellow, coral and purple.

Fall is the best time to plant peonies, especially if they are transplants. Spring is okay too if you are ready to make the addition. They will certainly be happier in the ground than in a nursery pot for the summer. If you can be patient for fall, shop for your favorite varieties now and order bareroot tubers from a peony grower for delivery in September.

Select a planting site that receives at least six to eight hours of sunlight each day for best blooms. Peonies will tolerate some shade but may not flower if light is limited.

Many planting recommendations direct gardeners to amend the soil in the planting area with organic matter and fertilizer. This recommendation is controversial among professionals, as mixing compost into the planting site sometimes creates what is essentially a clay pot in the ground and fertilizer may be unnecessary. Peonies do need well-drained soil. If planting in a flower bed that has had additions of compost and mulch or has been worked previously, the soil may be adequate.

If peonies will be planted in an area that was previously grassy, compacted or otherwise poorly drained, consider amending the soil in a larger area that what is needed for planting. Add compost over the entire area and mix it into the soil. This allows the roots plenty of room to grow.

To determine if fertilizer is needed, do a soil test prior to planting.

If planting a peony from a nursery pot, pull the plant from the pot, loosen the roots, dig a hole that is the same depth, and put the plant in the ground so that the soil depth remains the same as it was in the pot. If the plant will be mulched, set it a little high so that the top of the mulch will be even with the top of the soil from the pot.

If planting bareroot peonies or divisions (typically done in fall), place each tuber in the ground with the uppermost eye (pink/red bud found on the root) about 1 to 2 inches below the soil surface. Each tuber should have three to five eyes on it. Again, account for mulch depth as well as soil.

Tree peonies may be planted in spring or fall and are best planted rooted in a nursery pot. They are usually grafted plants.

Peonies may take a year or two after transplanting to begin blooming again.

The only maintenance needed is to remove the spent foliage from herbaceous peonies annually. Clip it back to ground level and dispose of it. Clipping the foliage in late fall and removing it gets rid of any leaf-spotting pathogens. But spent foliage can also be removed in early spring before new shoots appear.

Ants are often found on herbaceous peonies and are sometimes thought to be a nuisance. They feed on nectar from the flowers but do not harm them. They also protect blossoms from other insects that might feed on the petals. When peonies finish blooming, the ants will move on and find other food sources.

— Jennifer Smith works in regulatory horticulture and has worked as a horticulturist for various government entities. She has experience in landscape design and maintenance and as an educator.


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