Petunias are flowering plants, and skunks aren't known to actively eat them.
However, skunks might dig in your flower beds for other things:
* Insects and grubs: These are a favorite food for skunks. They might dig up your flower beds to find them.
* Shelter: They may dig under your plants for a place to rest or hide.
If you're concerned about skunks in your garden, you can try deterrents like motion-activated sprinklers or strong-smelling substances (like mothballs or garlic).