Why Does My Peony Look Unhealthy?

Are the flower buds absent from your peony?

Have the flower buds stayed closed?

Have the flower buds died or did the flower petals get distorted?

Do the stems have sunken lesions in them?

Do the shoots wilt and collapse, crowns may have gray mold on them?

There are several causes for absent buds in peonies: Improper planting, excess shade, immature plant, excess nitrogen, disturbing roots, or large, old crown. Peonies prefer full sun and moist, well-drained soil rich in organic matter. Set rootstocks so that the reddish buds or "eyes" are no more than l-2 inches below the soil surface. Do not apply high-nitrogen fertilizers. If mature peonies stop blooming, rule out other possible problems and divide if needed.

Peonies are very sensitive to extreme weather. Their flower buds will stay closed in case of a late spring frost, drought, high temperatures and low soil fertility. Water your plants so that the soil is always moist and feed peonies with compost or a slow-acting, general-purpose fertilizer in spring. If the summer heat is the problem, plant early flowering cultivars.

The most likely cause is Flower thrips. These insects feed on buds, stem tips, and flowers, causing distortion or white, brown or red flecks. Thrips are hard to control because they burrow into plant tissue. Remove and destroy infested plant parts. Encourage natural predators such as pirate bugs, lacewings, and lady beetles.

The most likely cause for these symptoms is Anthracnose. Keep plants dry when watering to prevent spread. Cultural controls such as regular fall cleanup and thinning stems to improve air circulation are effective. Treat severe problems with copper fungicide sprays.

Several fungi cause blights or stem and crown rots in peonies. Botrytis blight causes shoots to wilt suddenly and fall over and can cause the stem bases to blacken and rot. Gray mold may appear near the soil, buds may wither and blacken. Remove and destroy infected plant parts. Don’t put manure near plant crowns; clear mulch from crowns in spring to let the soil dry. Avoid overwatering and wet, poorly drained soil.

If the whole plant looks stunted, the leaves are yellow and spotted and the roots have tiny galls on them then the culprit is Root-knot nematodes. Prevent root-knot nematodes by applying chitin or introducing parasitic nematodes to the soil before planting. Solarizing the soil also helps in preventing root-knot nematodes.