What is a good cat deterrent for use in my garden?

They don't like citrus, human hair, rue, lavender, and lemon thyme. You could drop hair around, get it from local hair shops. Plant some of the items they don't like in your flower bed, if it will work. There are probably others but these are the ones I know about.

Hi Sandy, the best thing I've found to keep animals from digging in my beds is to cover the ground around the plants with chicken wire and then cover that with mulch so its not an eyesore. Besides that I know cats hate any kind of citrus plants such as lemongrass, that might help detour them.

They are likely digging up your flower beds after using it to urinate. They want to be able to dig after urinating. Coffee grounds, pipe tobacco, oil of lavender, lemongrass, citronella, and eucalyptus also deter cats. Cats will only go the restroom where they can dig. By placing chicken wire with the sharp side facing down, lattice fencing, or river rocks over the soil will keep feral cats from using your garden as a litter box.

Nature's Mace Cat Repellent at Amazon

"This concentrate can be sprayed outdoors and makes anything it comes in contact with unappealing to a cat’s sense of smell and taste."

I sprinkle cayenne pepper or chili powder on my lawn and garden. One sniff and they remember. Reapply when needed.

I have one area that is all lavender, they love to hide in there. Don't think the lavender works. Tried orange peals to where it looked like I had used orange mulch! Citrus, lavender, human hair, and coffee grounds did't work for me. Hoping you have better luck.

My ground cover finely filled in. So they just hid in the lavender now