How to Care for Peonies?
by
Tami Clark
+2
For two years now my peony bushes are loaded with blooms but only one or two open and the rest look as though they've rotted. What am I doing wrong, is there a way to fix this? 
You should know that ants are essential to peonies bloooming. If you have anything that might be toxic to the ants, it could be keeping the flowers from blooming,
They are planted amongst lemon balm, violas, clematis & yarrow.
This sounds like Botrytis blight, its a mold that occurs to the buds when they experience wet and cool/cold weather in early spring. I'm so sorry to see this for you :( I'm going to go home tonight and give my peonies a proverbial hug. Reading about it they say that it can spread so cut it off your plants immediately and discard them by burning or throwing directly in the trash. Here's the site I'm looking at:
https://viettes.wordpress.com/tag/peony-buds-rotting/
Are they in the right semi shaded area? Are they getting to much water? How old are the peonies?