Updated: Feb 20, 2019
Just like a natural ecosystem, your planting design should always be looking for balance. Creating biodiversity is one way, but planting many species of plants, which in turn attract many species of animals, can cause its own issues.
In managed systems, occasionally, nature needs a hand to retain balance. By designing your plantings, you can use plants to help protect each other from predators.
Many plant combinations use scents to deter pests.
Rabbits will eat a wide variety of vegetation given the chance. However, some plants actively repel them. The herbs, rosemary, sage, and thyme are effective repellents when planted with crops such as lettuce, beans, and peas.
Onions and garlic are deterrents for most animals.
The common means of keeping deer from eating the crops is effective fencing or hedge. Using shrubs and bushes with thorns along the border, or planting a clumping bamboo hamper the deer, who always keep a means of escape in mind.
Fragrant herbs are also effective in keeping deer away. They dislike the aromas. Planting sage, mint, rosemary, dill, or oregano amid your more vulnerable crops helps to deter deer. These plants have the additional advantage of attracting beneficial insects to your design with their bright flowers.
Daffodils and sunflowers also repel deer.
Daffodils can do double duty as a deterrent for squirrels as well as deer. Squirrels know that daffodils are poisonous and avoid them. By planting a circle of flowers around trees that are vulnerable can prevent squirrels destroying bark and fruit of the trees. Malodorous plants, like onions and garlic, also repel squirrels.
Raccoons enjoy eating a variety of plants as well as digging up the ground and mulch in search of edible insects. In particular, raccoons like to eat the young, tender ears of corn before they are ready to harvest. One way of keeping them away from the corn is to plant squash around the edge of the crop. Raccoons do not like walking on the prickly vines of the squash and if the planting is broad may act as an effective border.
Given that moles remain chiefly underground, they can easily go undetected. While they eat insects, their movement through the ground can damage plant roots. Chives, garlic, leek, onion, and shallots are good crops to plant to repel moles. These plants will also will keep dogs and cats from the cash crops, and from killing beneficial birds.
Lavender, mint, and marigolds are effective for repelling rodents. By planting them around the chicken coop and other areas that contain feed, they will look elsewhere for food.
Including a small patch of wildlife favorites into your design, away from your main crops, should help protect other crops you wish to eat by averting the animals attention.