Anise oil, Ro-pel and Thymol as well as other repellents sold at pet stores and garden centers may be effective in repelling cats. Be sure to follow label instructions, as some may not be labeled for use around food crops. Keep cats indoors or negotiate with neighborhood cat owners to do so. If cats continue to show up on your property, call you local animal control. Avoid feeding pets outdoors.
Food is an invitation for stray animals and neighborhood pets as well as wildlife.
Remove brush and other cover where animals are apt to hide or live. Keep the vegetation in the area clipped. Some animals are attracted to compost piles. When composting, use a covered and walled compost bin. Bury fresh materials in the pile.