One of my favorite spring flowers for perennials is the peony. Peonies are a long-lived perennial that you should be able to enjoy for decades.
A few years after Sharon and I got married; my parents gave me a collection of four different peony varieties.
A friend and reader of mine asked me why her peonies were not blooming. She reported that the flower had a brown leaf covering the flower bud. This bud died.
I would have counted my season almost a loss with such a major failure as my peonies not blooming.
On my strolls, I enjoy their scent. For me, summer is in full swing when peonies are in bloom.
The Qing dynasty declared the peony the national flower in 1903, and in recent years it has fallen out of favor.
The Indiana General Assembly made the peony the state flower in 1957.
Paintings from the Middle Ages depict artwork featuring peonies with their ripe seed capsules, believed to ward off certain evil spirits. Popularity can be a fickle thing.
I could see that the flower buds were brown to black, indicating the presence of botrytis.
These three peony buds that have botrytis. Credit: Eric Larson.
Botrytis on peony plants can impact the stems, leaves, and flower buds. One of the common names is Gray Mold, but to me, it has little to do with anything gray.
The peony is infected with brown leaves, stems, and flower buds.
Peony botrytis blight is commonly responsible for the loss of flower blooms. When infected, peony buds form but turn brown and die before they can open.
This Botrytis blight in peony, Botrytis paeoniae, is a fungus which, while unsightly and concerning, is not deadly. Cool, wet early springs followed by warm, wet early summers spread this fungus.
These conditions make it ideal for this soil fungus to develop.
Solutions for managing botrytis are maintenance solutions.
Most fungal diseases flourish in high-humidity locations. Botrytis is no exception, which means that you need to plant no closer than two to three feet apart.
Good air circulation is critical for keeping the foliage dry and preventing the growth of fungi.
Fungal spores spread when water drops hit a spore sac. When you water at the base of the plant, you remove the chance for wet leaves where botrytis has grown.
Early morning watering is preferable so that any water on the foliage can dry during the day.
Regularly pruning your peonies and removing any diseased foliage during the fall cleanup will go a long way toward managing the disease. Botrytis resides in the leaves, stems, and blossom debris over the winter.
Mulch spread under the peonies stops the splashing of water that spreads these soil-borne spores. Spores eject from the spore sacs as drops splash them.
Peonies grow best in rich, well-draining soil. Overly wet soil will contribute to the disease spreading.
Removing infected buds immediately when you see them stops the spread of the disease. This pruning will prevent the disease from infecting the healthy part of the plant.
Be alert when we begin to experience cool and damp weather. By being vigilant during the rainy, cool spring and removing the diseased portions of the plant, you can have a healthier plant.
As a designer, I have recommended installing plants that are resistant to botrytis. Peony cultivars ‘Bartzella,’ ‘Coral Charm,’ and ‘High Noon’ are all resistant to botrytis.
Bordeaux mix is a fungicide that has been used for centuries and is found at local garden centers. Follow the directions on the label when using this copper-sulfur organic fungicide. Spray the shoots as they emerge.
Again, spray when the leaves emerge.
Then, weekly or bi-weekly, as the flower buds begin to form.
At Walnut Ridge in Orrville, Ohio, on June 3, 2025, the third annual Peony Festival was celebrated.
If you choose to travel to Orrville next year, be careful, you may fall in love with these flowers, too.
I hope you have a great week strolling through your garden. Email at ericlarson546@yahoo.com if you see something.