Cats, whether yours or a neighbor's, are a nuisance when they decide your prized flower or vegetable bed is their new litter box. Not only is it uncomfortable to work in the garden when there are cat feces there, it isn't good for the plants. If you don't want to fence in your garden but still need to keep cats from defecating in it, you must make it an unattractive place to the cats. They will then go elsewhere to relieve themselves.
Measure the length and width of the garden bed. Add 5 inches onto each measurement then purchase a corresponding length of chicken wire with 1-inch mesh. Cut larger sections of wire to size with wire snips.
Cut slits in the chicken wire for any perennial plants it must go around in the garden. Lay the wire over the entire bed, slipping existing plants through the slits.
Bend the overhanging edges of the wire down, then press them into the soil. This prevents the wire from being pulled up by cats scratching at the edge of the bed.
Lay a 1 inch layer of mulch over the wire to disguise it if desired. Use straw or wood bark mulch. Cats scratch after defecating, which is uncomfortable because of the wire. This leads them to quickly find a new area to use.