Q.Why Do My Peony Roses Look Burnt And Crisp On One Of My Bushes And The Other Two Have Not Flowered At All Since I Planted Them ?
I’m thinking the burnt looking bush may be caused by a fungus ? What do I treat it with and would it help to cut it right back to ground level ?

Certified GKH Gardening Expert
You don't say how long ago you planted them, but they need to be well established before blooming. They need full sun, fertilizer, a cold period in winter and should be planted at the proper depth. The article below gives reasons peonies aren't blooming and what to do.
The burned looking edges could be peony leaf blotch, which is a fungal infection. It is best controlled with good sanitation and cultural practices. Diseased stems can be cut off at ground level, and removed in the trash along with any fallen leaves.
These articles should help:
https://www.gardeningknowhow.com/ornamental/flowers/peony/why-your-peony-buds-but-never-flowers.htm
https://yardandgarden.extension.iastate.edu/faq/why-are-my-peony-leaves-getting-brown-spots

