Experts and BHG readers answer.
Peonies leaning over
Thanks for writing. Peonies tend to be a little top heavy; it's natural (and common) for them to lean and droop over the top of their cages when they have lots of blooms. If you cut off all the old blossoms once they fade, you may find they stand up a little more easily.
---Justin, Senior Garden Editor, BHG.com