Chipmunks often target ripening tomatoes just as they become ready for harvest. The damage inflicted by these small rodents is typically distinct, appearing as small, shallow holes or scooped-out sections near the base of the fruit. This damage pattern differs from the deeper bites of squirrels or the small pecking marks left by birds, allowing for accurate identification of the pest. Chipmunks seek out the soft, juicy flesh of the tomato for its high water content, particularly during hot, dry weather.
Implementing Physical Barriers
The most reliable method for protecting a tomato harvest involves creating a physical barrier to exclude chipmunks completely. This strategy is highly effective because it directly prevents access to the plants. The material of choice is galvanized hardware cloth with a mesh opening of one-quarter inch or smaller, which is small enough to block rodents from squeezing through.
The barrier must address the chipmunk’s ability to climb and burrow. The wire mesh should extend at least two and a half to three feet above the ground to deter climbing. Crucially, the bottom of the fence requires burial, ideally six to twelve inches deep, to prevent tunneling underneath. Creating an L-shaped barrier, where the buried portion extends outward away from the garden row, makes it difficult for a chipmunk to dig past the protection.
Sensory Deterrents and Repellents
Methods relying on taste and smell offer a temporary solution but are less reliable than physical exclusion. Capsaicin-based repellents, derived from hot peppers, irritate the chipmunk’s sensitive nasal passages and paws. Commercial sprays or homemade mixtures using pure cayenne powder can be applied directly to the surrounding soil or non-edible parts of the plant.
A significant drawback of these sensory deterrents is the need for constant maintenance and reapplication. The effectiveness of capsaicin sprays is severely diminished by moisture, requiring reapplication after rainfall or overhead watering. Even in dry conditions, the repellent effect may only last between 48 and 72 hours. Predator urine, such as that from foxes or coyotes, can also be used to signal danger, but it faces similar limitations regarding wash-off and sustained potency. Electronic ultrasonic devices are available, though their effectiveness in garden settings remains limited and debated.
Modifying the Environment
Chipmunks are attracted to environments that provide both easy food and secure shelter, so altering the habitat can reduce your garden’s appeal. Eliminating potential cover is an effective step, which includes clearing away piles of stacked wood, fallen debris, and excessive ground cover near the growing area. These materials offer secure places for chipmunks to hide, nest, and establish their burrows.
Removing alternative food sources from the vicinity also helps to minimize rodent traffic near the tomatoes. Spilled birdseed from feeders, fallen nuts, or overripe fruit should be cleaned up regularly, as these items are highly attractive to chipmunks. Since chipmunks often seek moisture during dry periods, providing a dedicated water source away from the garden may discourage them from chewing on tomatoes just for hydration.
Trapping and Relocation Options
Active removal should be considered a last resort when other preventative and deterrent methods have failed to control a severe infestation. Small, fine-mesh live traps are suitable for non-lethal capture. They should be baited with highly appealing food items; peanut butter, sunflower seeds, or a mixture of peanut butter and oatmeal are effective lures when placed at the back of the trap behind the trigger plate.
It is important to check with local wildlife authorities before attempting to relocate any captured animal, as regulations concerning the trapping and release of wildlife vary significantly by state and municipality. Relocating chipmunks often results in poor survival rates because the animals are separated from their established food caches and burrows, which are essential for their survival, particularly before winter. If lethal control is necessary, rat-sized snap traps can be used, but they must be placed in covered bait stations to prevent catching non-target animals.