Peony Diseases and Problems

Plant peonies and you’re gracing your garden with an easy growing perennial. Peonies may look like divas when they’re in full bloom, but these hardy beauties are pretty bulletproof, provided they’re given the right growing conditions. But even tough perennials can encounter issues, and peony problems, including peony diseases, peony wilt and the dreaded “peonies not blooming” can occur.

When a peony’s not blooming, potential causes are many. This is probably the most common peony problem gardeners encounter with this pretty bloomer. Some of the reasons why peonies don’t bloom include simple issues, like plants are too young and still immature. Many peony varieties take three years to produce ample and typical flowers. The other reason many peonies fail to flower is due to deep planting. Eyes on peony tubers should be just below the soil surface—1 to 2 inches (deeper in colder regions).

Flower buds can be killed by late freezes, and too-high temperatures can cause the late, fully double peony varieties to fail to flower. Another common reason for peonies not blooming is that plants may not be getting enough light. If peonies are leafy and taller, they may be stretching for light. Check nearby shrubs and trees to determine if peonies are shaded.

Heavy nitrogen fertilizer can also be responsible for peonies not blooming. Be careful when planting peonies near lawn areas. Make sure you aren’t over-fertilizing the lawn with nitrogen-rich food. The same is true for peonies growing near shrubs or in other garden areas. If you apply fertilizer packed with nitrogen, peonies may respond with dark green, super healthy leaves and no flowers.

Peonies are not really plagued by pests. Their biggest issue usually occurs with various fungi, which cause several common peony diseases. During wet growing seasons, botrytis blight can develop. Symptoms include black or brown patches on leaves, cankers on stems and stems that turn black at the base and fall over. Flower buds turn brown and fail to open when botrytis is present.

Control this peony disease by removing any affected leaves as soon as you spot problems.
Deadheading peonies helps, as does cutting back peonies in fall. When botrytis appears, it’s very important to clean up the peony patch of all plant debris in fall, putting it out with the trash.

Powdery mildew is another of the common peony diseases which covers leaves with a white powdery coating. This peony disease doesn’t seem to have a huge impact on the plant’s long-term performance, but if it occurs, it’s important to tackle cutting back peonies in fall and destroying all plant parts.

Peony wilt is another disease caused by a fungus. Typically when this fungus is present in soil, it infects the plant, causing just a few stem tips to wilt. If you suspect you have peony wilt, contact your local extension office and learn how to have stems tested. If peony wilt is present, you’ll need to dig and destroy the plant and avoid planting any peonies in that same spot in future.