The sudden appearance of disturbed soil and missing plants points to nocturnal wildlife searching for a meal. Identifying the animal responsible is the first step toward effective mitigation, as damage patterns provide distinct clues about the pest’s motivation and method. The difference between an animal looking for protein under the soil and one looking for the bulb itself determines the best approach for protecting your garden.
Identifying the Grub Hunters
The most widespread type of nighttime digging is not an attack on the bulb, but a search for protein sources like earthworms, insect larvae, and grubs located just beneath the soil surface. Animals with a keen sense of smell, such as skunks and raccoons, are attracted to these subterranean caches of food, especially in the late summer and fall. The pattern of damage they leave behind is highly distinctive.
Skunks are precise, methodical foragers that leave behind numerous small, shallow, cone-shaped holes, roughly the size of a quarter or their own nose. They use their long front claws to create these divots, systematically excavating a single grub or insect at a time. A lawn or garden bed disturbed by a skunk often looks like it has been lightly aerated with a small tool across a wide area.
Raccoons, in contrast, are much less delicate, utilizing their highly dexterous front paws like hands to tear up larger sections of turf. They often leave behind mats of sod that have been ripped up and rolled back, making the area appear as though a section of carpet has been peeled away. This more extensive damage occurs when they locate a dense concentration of grubs and quickly flip the soil layer to access the entire food source at once.
The Bulb Eaters and Caching Agents
A different set of animals causes more targeted damage because the bulb itself is the intended meal or a temporary storage site. This damage is typically deeper and directly over the planting site, focusing on the nutrient-rich bulb. These culprits often operate overnight, especially when freshly turned soil makes the planting site easy to locate.
Squirrels and chipmunks are common culprits, digging up bulbs to consume immediately or burying them for later use (caching behavior). Their digging results in deep, focused holes exactly where the bulb was planted, often leaving behind the outer, papery tunic. This targeted excavation is a direct response to the bulb’s appealing aroma and the visual cue of loose soil.
Subterranean rodents, primarily voles and gophers, pose a threat from below, sometimes using existing tunnels. Voles eat the entire bulb, leaving behind only an empty cavity or a hollowed-out shell. Gophers also consume bulbs and create distinct soil mounds near their tunnel entrances, often leading directly to the planting site.
Effective Prevention and Repellent Strategies
Protecting bulbs from nocturnal digging requires a layered defense that addresses both surface foragers and subterranean pests. One of the most effective strategies is to use physical barriers at the time of planting. For surface diggers like squirrels and raccoons, laying a piece of chicken wire or mesh netting flat over the newly planted area and securing the edges will deter digging until the soil settles and the scent dissipates.
To protect bulbs from subterranean threats like voles and gophers, a more robust barrier is necessary. Bulbs can be planted within a cage constructed of half-inch hardware cloth, which is a stiff, durable wire mesh that fully encloses the bulb on all sides. This barrier allows roots and shoots to grow through while blocking rodents from reaching the bulb underground.
Sensory deterrents can also be highly effective in making the area unappealing. Mixing crushed stone, oyster shells, or coarse gravel into the planting hole deters burrowing animals, as the sharp texture is painful to their sensitive paws and discourages excavation. Applying commercial animal repellents, often made with ingredients like dried blood or capsaicin, directly to the soil surface can mask the bulb’s appealing scent.
Finally, planting less appetizing bulb varieties, such as daffodils and snowdrops, discourages pests because they contain the toxic alkaloid lycorine. These distasteful bulbs can be strategically planted around desirable targets like tulips to create a natural perimeter defense. For grub hunters, treating the lawn with beneficial nematodes or milky spore reduces the grub population, eliminating the incentive for skunks and raccoons to dig.