Covering your outdoor garbage will also help deter other nighttime wildlife, like racoons.
Typically, you can safely mulch twice a year.
Be sure to use large rocks, not pebbles. Cats don’t really mind stepping on small rocks, but they’ll stay away from bigger ones.
The spikes won’t actually hurt the cats, but they will feel a little uncomfortable on their paws.
The sprinkler won’t turn on unless something walks in front of it, so you won’t be wasting any water.
You can also plant lavender, rosemary, lemongrass, and rue in your garden. All of these plants put off a smell that cats don’t like. Smells diminish over time, so be sure to replenish your scent deterrents every few weeks or so.
Ultrasonic alarms are also effective against other nighttime critters, like raccoons, opossums, and rodents.
Chicken wire is a great solution if you have critters munching on your plants, too. It helps keep out bunnies and deer, which are both pretty destructive to gardens.
Cats are usually pretty small, so get creative when looking for their shelter spots. They might even hunker down underneath large bushes or tall trees.
If you have roaming cats outside without owners, consider calling your local animal shelter and asking about a spay/neuter program. Many shelters will use catch-and-release methods to fix stray cats and prevent new stray kittens.