Do you mean the new growth has died, or just that they disappeared underground over winter?

Peonies are fully herbaceous and may well not start growing for another month

Some of ours have just started to put up noses from the soil. I think that you are seeing last years foliage dying off, Violet, and that there is nothing wrong wioth them.

Paeonies are very hardy so it is unlikey that even our hard winter has killed them. Like Bulbaholic, mine are just starting to show new growth at ground level

Thanks to all who responded to my question-I'll just have to wait to see if any new growth! Violet