Squirrels commonly eat dahlia bulbs, also known as tubers, which is a widespread frustration for gardeners. These rodents are notorious for digging up and consuming newly planted bulbs, especially during periods of high foraging activity. This behavior is driven by the squirrels’ constant need for food, making dahlia plantings an easily accessible target. The problem is particularly noticeable immediately after planting, signaling the need for protective measures.
Why Dahlia Bulbs Attract Squirrels
Dahlia tubers are an appealing food source due to their density and nutrient composition. Like other root vegetables, the tubers contain a high concentration of starches and carbohydrates, providing quick energy for a small mammal’s active lifestyle. This calorie-rich food is especially attractive during the fall and early spring planting seasons when other natural food sources may be scarce.
The soft, fleshy texture of the dahlia tuber also makes it easy for squirrels to consume quickly. The act of freshly tilling the soil to plant the tubers often signals that a new food source has been buried, similar to how they bury their own nut stashes.
Identifying Squirrel Damage in the Garden
Gardeners can distinguish squirrel activity from other pests by observing specific patterns of damage. Squirrels typically leave shallow, messy excavations, often only 1 to 3 inches deep, directly above where the bulb was placed. They use their front paws and noses to push aside the soil, resulting in a distinct, scattered appearance to the dirt.
A clear sign of squirrel damage is finding partially eaten tubers or entirely removed bulbs lying on the soil surface nearby. Squirrels may take a single bite, discard the item, or relocate the entire bulb. This is distinct from the damage caused by underground rodents like voles, which create clean, deep tunnels and consume the entire bulb from below. If the bulb has vanished completely without a trace of a hole, it may have been carried away by a squirrel or chipmunk.
Practical Methods for Protecting Bulbs
Protecting newly planted dahlia tubers requires combining physical barriers with scent and taste deterrence. The most effective approach involves placing a physical barrier directly over or around the planting area. For individual tubers, creating a cage from hardware cloth can prevent access from above and below.
Physical Barriers
Planting the tuber inside a small, bottomless wire cage or surrounding it with hardware cloth offers a strong defense against digging. The mesh should have a grid of a half-inch or less to prevent the squirrel from reaching the bulb while allowing the shoots to grow through.
For larger planting areas, a sheet of chicken wire or hardware cloth can be laid flat over the soil surface and secured with landscaping staples or weighted down with stones. This covering should remain in place until the dahlia sprouts have grown a few inches tall, at which point the bulbs are less attractive to the animals.
Another effective physical deterrent is mixing sharp, gritty material into the top layer of soil. Integrating crushed oyster shells or coarse gravel around the planting site discourages squirrels from digging because they dislike the feeling of the jagged material on their paws. This method makes the act of digging uncomfortable and often prompts the squirrel to seek an easier foraging spot.
Taste and Scent Deterrents
Squirrels possess a highly developed sense of smell and taste, which can be exploited using pungent, non-toxic materials. Applying a liberal dusting of cayenne pepper, chili powder, or cinnamon directly onto the soil surface creates a taste and scent barrier that squirrels find offensive. The active compound in chili, capsaicin, causes a harmless burning sensation that deters them from digging.
Strong-smelling natural substances like crushed fresh garlic or peppermint oil can also be used to repel the rodents. For liquid application, a mixture of castor oil, dish soap, and water can be sprayed on the soil to alter its flavor and odor, discouraging digging. Note that pungent organic fertilizers like blood meal, while beneficial for plants, can actually attract squirrels due to the strong odor, so synthetic fertilizers are often a better choice during initial planting.