Planting a garden is an investment that can be quickly undone by hungry wildlife. Seedlings, which are young plants recently germinated or transplanted, represent the most vulnerable stage of a plant’s life. Their tender stems and leaves are highly palatable to a wide range of animals. Damage can range from a few nibbled leaves to the complete severing of the stem, resulting in the instant loss of the crop. Protecting these delicate starts requires a strategic, multi-layered approach using a combination of physical defenses, sensory deterrents, and localized protection to ensure survival.
Physical Barriers and Exclusion
Physical barriers are often the most effective and reliable defense against animal damage because they create an absolute separation between the plant and the pest. The design and material of the barrier must be matched to the size and behavior of the target animal. For large browsing mammals, such as deer, the primary defense is height. Perimeter fencing needs to be a minimum of eight feet tall to reliably exclude deer from a garden area.
A sturdy enclosure using woven wire or high-tensile mesh is necessary because large animals can exert considerable force. Alternatively, a double-fence design or angled fencing can confuse the deer’s depth perception and discourage jumping. For smaller areas, individual plants can be shielded with temporary cages or shelters that are at least four feet high and firmly staked into the ground.
Defending against medium-sized ground-dwelling animals like rabbits, woodchucks, and voles requires a barrier that extends both above and below the ground. Chicken wire or hardware cloth with a small mesh size, such as one inch or less, is the appropriate material for these lower fences. To prevent animals from digging underneath, the bottom of the wire must be buried six inches deep and then bent outward in an “L” shape away from the protected area. This buried flange, known as the L-bend method, deters animals attempting to tunnel into the garden.
Very small threats, including birds and squirrels, can be excluded using lightweight covers. Floating row covers, made of permeable fabric, allow sunlight and water to reach the seedlings while blocking access to flying and climbing pests. Individual seedlings can also be protected with homemade cloches, such as clear plastic bottles with the bottom removed. These barriers are useful for protecting newly transplanted seedlings until they develop enough foliage.
Sensory and Chemical Repellents
Repellents discourage animals through the application of unpleasant tastes, odors, or startling stimuli, rather than physically blocking entry. These methods rely on the animal’s natural aversion and are most effective when used consistently and reapplied regularly. Commercial repellents often use putrescent egg solids as a key ingredient, which mimics the smell of a decaying animal. This scent-based deterrent triggers a fear response in deer and rabbits, associating the area with a potential predator.
Taste-based repellents make the plant itself unpalatable. Capsaicin, the compound that gives chili peppers their heat, is an active ingredient in many commercial sprays. It provides a powerful deterrent that irritates the mouth and nasal passages upon contact. Since these products are applied directly to the plant foliage, they must be reapplied frequently, especially after rainfall or as new, unprotected growth emerges.
Non-chemical methods, such as visual and auditory deterrents, can create an environment that feels unsafe to wildlife. Motion-activated sprinklers use a sudden burst of water to startle and chase away animals. While animals are initially fearful of new objects, they quickly become accustomed to non-threatening stimuli like scarecrows or reflective tape. Once an animal realizes the deterrent poses no actual harm, its effectiveness diminishes, necessitating a change in tactic or location to maintain surprise.
Guarding Against Subterranean and Crawling Pests
Pests that attack seedlings at or below the soil line require localized defenses that protect the immediate base and root structure. Subterranean threats like gophers and moles destroy plants by feeding on roots or creating extensive tunnels that disrupt the soil structure. Protection is best achieved by planting seedlings within individual wire baskets, constructed from galvanized hardware cloth with a quarter-inch mesh. The wire cylinder should fully enclose the root ball and extend a few inches above the soil line to prevent above-ground entry by voles and other rodents.
Crawling pests, such as cutworms, are moth larvae that sever the tender stem of a seedling at the soil surface, causing the plant to collapse. A localized physical barrier around the stem is the most reliable defense against these nighttime feeders. Collars made from cardboard, aluminum foil, or plastic tubing should be placed around the stem, extending one to two inches below the soil and two to three inches above. This barrier prevents the cutworm from wrapping its body around the stem to girdle it.
Slugs and snails, which leave a telltale silvery trail, are a common threat to young foliage. Diatomaceous earth (DE), a fine powder made from fossilized diatoms, can be sprinkled in a ring around the seedling base. The microscopic sharp edges of the DE effectively dehydrate and deter these soft-bodied pests. Alternatively, a barrier of sharp grit, coffee grounds, or crushed eggshells can be used to make the soil surface less hospitable to their movement.