I have had 8 peonies for many years. This year I’m noticing on a couple of them fewer buds, some circular holes in the buds, and quite a few that are small, brown and dried up looking.
Most are in lots of sun, I have clay soil, but no conditions have changed for them.
Thank you for contacting Toronto Master Gardeners:
Our Toronto Master Gardeners Website provides information on peonies pests and diseases. The photo shows peonies that are healthy; they may be in competition with other plants. You may need to add compost to provide nutrients to the soil. Soil Fertility Toronto Master Gardeners Guide
Concerning the peonies that have buds that will not bloom, it can be bud blast which is caused by environmental stressors. Too much water, too little water, too much shade, removal of leaves in late summer, infertile soil. The Iowa State University has information on why peonies do not bloom: Why Peonies Do Not Bloom
There are also our website answers to why peonies do not bloom, peony pests and disease.
Good luck with your peonies.
June 3, 2024