Peonies that are sited well can survive and bloom generously for decades with minimal care. But sometimes seemingly healthy herbaceous peonies don't develop buds or peony buds form then fail to grow (called bud blast).

Herbaceous peony flowers are large and dense. They take an enormous amount of energy to form fully. Strong leaf development with no buds or buds stunted and brown is apt to occur for one of these reasons that deprive the plant of the strength needed to complete the flowering process.

• The plants are young and not mature enough to bloom yet or have been recently divided and need to recover.
• The leaves of the peony were cut back before they were fully brown last season or too many leaves were removed when flowers were cut for display last season. They need to photosynthesize as long as possible to gather strength to re-bloom in the following growing season.
• Plants around the peony have grown up and are creating increased shade; full sun is needed.
• Mulch or compost has been added and built up burying the roots too deeply, or heavy winter mulch was put down too soon in the season. Our increasingly warm winter weather can add to the problem. Without a good winter chill to allow complete dormancy, peonies get weak and may not complete the blooming process.
• Crowding and competition with other plants reduces the resources the peony plant has to thrive and  bloom.
• The buds may have been damaged after forming by strong frost in the spring just as buds are developing or by botrytis mold infection. (If botrytis is the issue, you will probably also see damage to new leaves and shoots).
• An over-fertilized plant (or one hit with stray, high-nitrogen, lawn feed application) may have been signaled to produce lush foliage rather than flowers.

For more information or growing health peonies see our Guide to Herbaceous Peonies.

Courtesy of NYBG Plant Information Service