Hydrangeas are highly valued for their large, colorful blooms, making them a popular choice for gardeners seeking to add structure and color to their landscapes. The sudden appearance of damaged leaves, missing buds, or severed stems can be extremely frustrating for homeowners. This damage is often a sign that various animals, from large browsing mammals to small ground-level pests, have found the plant’s succulent tissues to be an appealing food source. Identifying the specific animal responsible is the first step toward protecting these beloved ornamental shrubs.
The Primary Mammalian Culprits
The most visible and extensive damage to hydrangeas is caused by medium to large herbivores, namely white-tailed deer and Eastern cottontail rabbits. Deer browse on the tender new growth, flower buds, and leaves, especially when other natural forage is scarce in late winter or early spring. They are attracted to the high moisture content and digestibility of the plant material, often stripping a plant of its potential blooms overnight. Rabbits tend to feed closer to the ground, primarily targeting young plants or the lower stems of mature shrubs. They gnaw on the bark and lower stems, particularly during winter months when soft green vegetation is limited.
Smaller Pests and Ground-Level Threats
Damage is not always limited to above-ground browsing, as small rodents called voles pose a significant threat from beneath the soil. Voles are mouse-like rodents that create extensive tunnel networks, often feeding directly on the plant’s root systems and girdling the lower stems at or just below the soil line. A hydrangea suffering from vole damage will often wilt suddenly and appear dehydrated, even when watered correctly, because its roots have been severed. Gastropods such as slugs and snails are also common culprits, especially in damp, shaded environments, which hydrangeas often prefer. These mollusks feed on the leaves and tender shoots, leaving behind a distinct form of evidence, as they are nocturnal feeders.
Recognizing Distinct Damage Patterns
Determining the identity of the animal often comes down to analyzing the specific pattern of damage left on the plant. Deer lack upper incisors, so they tear vegetation away, leaving stems and leaves with a ragged, torn, or broken appearance, typically found three to four feet high. Rabbit damage is characterized by clean, angled cuts on stems, concentrated within a foot of the ground, due to their sharp incisor teeth. Slugs and snails leave behind irregular holes in the leaves, often accompanied by a silvery, tell-tale slime trail. Vole damage is identified by the sudden wilting of the plant, which will easily lift out of the ground because its main roots have been gnawed off.
Effective Management Strategies
Management strategies should be tailored to combat the specific animal identified by its unique damage pattern. For deer, the most reliable protection is exclusion, often requiring an eight-foot fence or a strategically placed electric fence. Chemical repellents, which use foul tastes or odors, can be effective but must be reapplied frequently, especially after rain. To combat rabbits and voles, physical barriers at ground level are highly effective; a low fence of wire mesh or hardware cloth buried into the soil prevents access to the stems and roots, and voles are also discouraged by removing thick mulch or groundcover. Slugs and snails are best controlled by reducing their habitat, such as clearing away debris and leaf litter, or by using barriers like copper tape or granular diatomaceous earth.