Tight peony buds that brown or shrivel without unfolding are a disappointing spring sight. Possible causes include fungal blight, bad weather during bud formation, and too little sunlight. Which one it is depends on what the buds look like.
Peony Buds Not Opening: What You See
The blighted bud looks different from a healthy one in spring, when the flowers should be swelling and showing color.
- Buds that turn brown or black and stay shut may have botrytis blight.
- In Washington, wilting buds may carry fluffy gray mold, with brown blotches appearing on the leaves later in the season.
- Young shoots discolor at the base, wilt and fall over, and stems soften and decay.
- Buds stay small, tight and colorless on a plant growing in partial to heavy shade.
- Little buds may die from internal rot after very rainy weather.
Where the buds sit on the plant and what the leaves look like around them tell you most of what you need to know.
From the almanac
Peonies in your state
The dates on this page depend on where you live. Your state's page carries its frost dates, its USDA zones and the year laid out month by month.
Northeast
Southeast
- Alabama
- Arkansas
- Delaware
- Florida
- Georgia
- Kentucky
- Louisiana
- Maryland
- Mississippi
- North Carolina
- South Carolina
- Tennessee
- Virginia
- West Virginia
Midwest
Southwest
West
Pacific Northwest
Canada
Peony Buds Not Opening or Something Else?
Several problems, including fungal diseases, can leave a bud closed. Matching the bud’s look to its surroundings and the season sorts them out quickly.
Cut flowers bought for arrangements have their own version of the problem, since stems with very tight buds and no color may never open.
| Looks like | How to tell them apart |
|---|---|
| Frost damage | Buds may fail to open after a late spring freeze. |
| Shade starvation | In Iowa, plants in partial to heavy shade may be too weak to develop their buds fully. |
| Botrytis blight | Buds blacken and stay shut, with gray mold on them, spotted leaves and soft stems, most often after cool, rainy weather. |
Extra fertilizer, a clump that needs dividing, and insect damage can also keep buds from opening.
What Causes Peony Buds Not Opening, and Where It Is Worst
The fungus Botrytis paeoniae attacks stems, leaves and flower buds, and it is most common in cool, rainy weather. It also thrives in dark, moist places, and infections often show up behind the buds just before they open.
Weather without disease can do the same damage. Buds formed during very rainy weather may rot inside, because the plant missed its window at a critical point in bud development. Possible causes also include late freezes, other extreme weather, fungal diseases, insects and poor nutrition.
Shade is the quiet cause. Peonies bloom best in full sun, and in partial to heavy shade the plants are weak and cannot feed the developing buds, so the undernourished buds do not develop fully. Botrytis blight is most common in cool, rainy weather.
How to Treat Peony Buds Not Opening
Sanitation is the most effective way to deal with blight, so most of the work is cleanup, followed by a look at light and feeding.
- Check the leaves and the base of the shoots for spots, soft stems and discolored tissue to confirm whether blight is behind the trouble.
- Partial to heavy shade can leave peonies too weak to develop buds fully.
- In Iowa, move peonies growing in partial to heavy shade to a sunny site in September.
- If a plant was fertilized more than its neighbors, extra feeding may be part of the problem.
A clump that needs dividing may also produce buds that fail to open.
How to Prevent Peony Buds Not Opening Coming Back
Prevention follows the year, with the biggest job in fall and the rest being watchfulness in spring.
- In Indiana, start controlling blight with a thorough fall cleanup of old, infected stems, leaves and other plant debris.
- In Iowa, check young shoots for discolored bases, wilting, or stems that fall over.
- Cool, rainy spring weather favors botrytis, so watch buds and leaves for symptoms.
- Skip cut stems with very tight buds and no color; also check for gray mold before buying.
Full sun supports bloom, and fall cleanup helps control blight.
Where This Comes From
These details are based on plant-health guidance. Check what suits your local weather and soil.
Common Questions
Can Peony Buds That Turned Black Still Open?
No. Buds that blacken and fail to open will not bloom.
Why Do Peony Buds Fail to Open After a Rainy Spring?
Very rainy weather can cause internal rot in small buds while they are forming. Wet springs also favor botrytis, which blackens buds and keeps them closed.
Is It Safe to Compost Diseased Peony Stems?
Remove old, infected stems, leaves and other plant debris in fall.