Daffodils are a welcome sign of spring, but these cheerful flowers and their buried bulbs face threats from various garden pests. Daffodils are famously toxic due to the alkaloid lycorine, which concentrates most heavily in the bulb. While this compound typically causes gastrointestinal upset in mammals, leading many grazing animals to avoid them, toxicity is not a complete defense. Different pests target various parts of the plant for different reasons.
Pests Targeting Leaves and Flowers
Damage to the above-ground parts of the daffodil is almost always caused by larger mammals, primarily deer and rabbits. These opportunistic feeders may sample daffodil foliage, especially when other food sources are scarce early in the season. Although they generally avoid the plant due to its bitter taste and toxicity, the first few emerging leaves can still be a target.
Deer browsing typically results in a ragged, torn appearance on the leaves and stems because they lack upper incisors and must pull and twist the plant material to break it off. Damage from rabbits, conversely, appears as a clean, angled cut, as they use sharp incisors to snip the plant close to the ground. Squirrels occasionally nibble on flowers, but they are more commonly associated with digging up and damaging the bulbs underground.
Pests Targeting the Bulb Underground
Below the soil line, a different set of culprits is responsible for the disappearance or failure of daffodils to emerge. Voles and gophers are the primary threats to the bulb. Voles, which are small, mouse-like rodents, create shallow, meandering tunnels and runways just beneath the surface of the soil or mulch. They typically feed on the bulb from the outside, leaving behind ragged holes and sometimes only the papery tunic.
Gophers, which are larger tunneling rodents, are known to pull entire plants down from below, resulting in a sudden disappearance of the daffodil. Their presence is often indicated by fan-shaped mounds of soil near the feeding site. The Narcissus Bulb Fly (Merodon equestris) is another significant pest. The female fly lays eggs near the base of the daffodil in late spring or early summer, and the resulting maggot burrows into the bulb. This larva feeds within the bulb, often reducing the interior to a soft, rotten mass and preventing the plant from flowering the following season.
Comprehensive Deterrent and Protection Methods
Protecting daffodils requires a multi-pronged approach that addresses both above-ground grazers and subterranean pests. Effective physical exclusion is often the most reliable method for large mammals. Fencing should be at least eight feet high to deter deer, or a double-fence line with two shorter fences spaced a few feet apart can be effective. To stop rabbits, a chicken wire fence needs to be at least two feet tall and buried six inches below ground to prevent burrowing.
Dealing with underground pests like voles and gophers often involves planting bulbs inside wire mesh cages. These cages are typically made of hardware cloth with a small, quarter-inch grid size. This barrier must fully enclose the bulb, including the bottom, to prevent access from below.
Repellents offer a secondary line of defense, especially against deer and rabbits, and are generally categorized as taste-based or scent-based. Commercial taste-based repellents containing ingredients like rotten eggs or capsaicin must be reapplied regularly, particularly after rain. Cultural practices also play a role, such as eliminating thick mulch or ground cover around the planting area, which reduces protective habitat for voles. For severe gopher or vole infestations, targeted trapping is an effective method of population control.