Planting flower bulbs in the fall for vibrant spring color is often undone by hungry wildlife. This process can be frustratingly undone by hungry wildlife, primarily foraging rodents like squirrels, chipmunks, voles, and gophers. They view the starchy bulbs as a valuable food source for the cold months. Protecting your investment requires a multi-pronged strategy focusing on physical exclusion, scent and taste deterrence, and making smart planting choices from the start.
Utilizing Physical Barriers to Protect Bulbs
Physical barriers offer one of the most reliable methods to prevent both surface-level digging and underground tunneling to access planted bulbs. For protection against subterranean pests like voles, creating a bulb cage using half-inch galvanized hardware cloth is highly effective. You can fashion a small basket with a closed top and bottom from the mesh, placing the bulbs inside before planting. This allows roots and shoots to pass through while blocking rodents.
For surface diggers, particularly squirrels that excavate bulbs immediately after planting, secure a piece of chicken wire or hardware cloth over the entire planting area using garden stakes after covering the bulbs with soil. This wire mesh prevents squirrels from digging down, yet the wide openings still allow the emerging foliage to grow unimpeded in the spring. Once the ground freezes or the bulbs sprout, the barrier can be removed.
Incorporating materials like sharp grit, crushed oyster shells, or coarse gravel into the backfill soil irritates the paws and mouths of tunneling animals. This abrasive texture is often enough to make a persistent pest abandon the effort. You can also plant larger bulbs deeper, such as six to eight inches down, which increases the physical effort required for a squirrel to reach them.
Applying Scent and Taste Deterrents
Making the bulbs or the surrounding soil unpalatable is an effective strategy. Commercial liquid repellents, often containing ingredients like dried blood or putrescent egg solids, create an unpleasant odor that mimics a predator presence or spoiled food. These sprays must be applied directly to the bulbs before planting and then reapplied to the soil surface periodically, especially after heavy rain, to maintain effectiveness.
Dusting the bulbs with a fine layer of cayenne pepper, red pepper flakes, or garlic powder before placing them in the ground can leave a lingering scent and a sharp taste that discourages foraging. The capsaicin in the pepper causes mild irritation that teaches a curious animal to avoid that particular food source.
Granular products, which often contain castor oil or other heavily scented compounds, can be spread over the freshly turned soil to mask the scent of the newly planted bulbs. While bone meal is sometimes recommended as a fertilizer, it can actually attract rodents, so using a less tempting organic fertilizer is advisable.
Choosing Pest-Resistant Varieties and Strategic Placement
Selecting bulb varieties that are naturally unappealing to pests is the simplest form of prevention, as many common spring bloomers contain compounds that are toxic or bitter. Daffodils, for example, contain the alkaloid lycorine, a substance that is poisonous to rodents, deer, and rabbits. Alliums, which are ornamental onions, emit a strong sulfuric odor that is repellent to most foraging animals.
Other bulbs with natural defenses include Fritillaria, whose bulbs have a distinctive skunky scent that makes them highly undesirable to voles and squirrels. Hyacinths and Muscari also possess a pungent fragrance that deters pests. Focusing your planting efforts on these naturally resistant options minimizes the risk of losing your entire spring display.
Strategic placement involves using these unappealing varieties to protect more vulnerable bulbs, such as tulips and crocuses. Planting the resistant bulbs around the perimeter of a bed containing desirable bulbs can create a protective, scented barrier that confuses pests. Another technique is to mix the resistant and non-resistant bulbs within the same planting hole, effectively hiding the desirable food source.