Squirrels, with their persistent digging and opportunistic foraging, frustrate gardeners attempting to protect bulbs, fruits, and vegetables. Deterrence aims to discourage these animals humanely by making the garden environment less appealing. Successful strategies utilize a multi-pronged approach, combining physical obstructions, sensory irritants, and environmental modifications. The most effective methods combine a direct block to access with a negative sensory experience.
Creating Physical Barriers
Physical barriers are the most reliable method because they directly block access to vulnerable plant material. To protect bulbs, bury a layer of hardware cloth or chicken wire one inch above the planted bulbs. The mesh must have small openings, allowing plant shoots to grow through easily.
For containers and raised beds, secure a layer of chicken wire or mesh to the soil surface to prevent digging. Garden netting can be draped over ripening produce, but it must be secured tightly at the base. Since squirrels are adept climbers, the covering must be fastened firmly to the ground or container edge.
To protect tree bark from gnawing, wrap the trunk with metal mesh or hardware cloth up to two feet high. Fencing around a garden should be metal and secured a few inches into the ground to stop digging underneath. Creating a smooth surface, such as vinyl, can also prevent climbing over perimeter fences.
Using Aversive Scents and Tastes
Aversive repellents capitalize on the squirrel’s sensitive sense of smell and taste. Capsaicin, the active compound in hot peppers, is an effective taste deterrent because mammals find its pungency extremely aversive. Studies show that capsaicin-treated seeds are largely avoided by squirrels.
This principle is utilized in commercial and homemade sprays, mixing capsaicin powder or hot sauce with water and a sticking agent like dish soap. Applying this spray directly to vulnerable plants makes them unpalatable. Sprays must be reapplied frequently, especially after rain or watering, to maintain the deterrent effect.
Strong-smelling natural substances also serve as effective sensory deterrents. Squirrels dislike the potent aromas of peppermint oil, garlic, and white vinegar. These scents can be applied by soaking cotton balls in essential oils or by sprinkling crushed garlic cloves or used coffee grounds. Predator urine granules can also be sprinkled to signal danger.
Adjusting the Garden Environment
Long-term deterrence involves modifying alternative food sources that initially draw squirrels to the area. Bird feeders are a primary attractant, so replacing them with squirrel-proof designs can significantly reduce garden visits. Weight-activated feeders close the feeding port when a heavier animal lands on the perch.
Another option is to use bird seed squirrels find less appealing, such as safflower or Nyjer seeds. Installing a dome-shaped baffle above or below a feeder pole physically prevents squirrels from accessing the seed. Motion-activated sprinklers deliver a sudden burst of water and noise when triggered, startling the animals without causing harm.
Strategic planting can create a natural barrier by incorporating species squirrels naturally avoid due to taste or smell. Daffodils and hyacinths contain toxic compounds, such as the alkaloid lycorine, which make their bulbs unappetizing. Similarly, plants in the allium family, including ornamental onions and garlic, emit a pungent odor that squirrels find repulsive, making them excellent choices to interplant with more vulnerable species.