Hosta plants are popular for shady garden spaces, offering lush foliage that brings structure and color. Unfortunately, their soft, broad leaves make them a prime target for various garden pests. Determining the specific animal responsible for the damage is the first step toward effectively protecting your hostas and ensuring their continued health.
Primary Surface Feeders
Deer, rabbits, and slugs are the most common animals that feed on hosta leaves above ground, often causing the most noticeable damage. White-tailed deer consider hostas a preferred food source and can consume an entire plant down to the stem in a single visit. Deer typically feed at a height between 18 and 24 inches, often leaving behind a jagged or torn edge on the remaining leaves due to their lack of upper incisor teeth.
Rabbits also target hostas, though their damage is usually less extensive than that of deer. These smaller mammals tend to eat leaves close to the ground, often starting from the edges and working inward. Rabbit damage is characterized by clean, angled cuts on the leaf tissue, which is a key difference from the ragged tears left by deer.
Slugs and snails are persistent pests, finding the hosta’s large leaves an ideal food source. These mollusks feed by rasping away the leaf tissue, creating irregular holes. They are nocturnal feeders, hiding during the day in moist areas and leaving a shiny slime trail that confirms their presence.
Secondary and Subterranean Pests
Beyond the primary surface feeders, other creatures can cause significant, albeit different, damage to hostas. Voles, small rodents, typically do not eat the foliage but instead target the plant from below ground. They chew on the hosta’s roots and crown (the base of the plant).
Vole damage often results in the entire plant wilting or becoming loose in the soil because the root system has been severed. A plant that suddenly collapses or can be easily pulled out of the ground is a strong indicator of vole activity. Other insects, like earwigs and grasshoppers, will chew on the leaves, causing small, irregular holes or ragged gaps. Earwigs often cause damage that mimics that of slugs but without the accompanying slime trails.
Diagnosing Damage Patterns
A close examination of the remaining foliage helps narrow down the culprit responsible for the damage. Large, ragged tears and heavy browsing high off the ground indicate deer. Damage isolated to lower leaves showing clean, angled cuts points to rabbits. Irregular holes passing through the leaf tissue, especially with shiny, dried mucus trails, strongly suggest slugs or snails. If the plant suddenly wilts or collapses, look for small, quarter-sized entry holes near the base, confirming a subterranean attack by voles.
Implementing Targeted Management Solutions
Effective pest control relies on strategies specific to the identified animal threat. For deer, physical exclusion is the most effective method, often requiring a fence at least eight feet tall to prevent them from jumping over. Alternatively, commercial deer repellents containing ingredients that offend their smell and taste, such as putrescent egg solids or garlic, should be applied weekly or after heavy rain.
Slug and snail control uses both physical barriers and targeted baits. Iron phosphate baits, safer for pets and wildlife than older chemicals, can be scattered around the hostas to eliminate the pests. Placing copper tape around the perimeter of container-grown hostas can also deter them, as the metal reacts with their slime to create a mild electric shock.
Voles, which attack the root system, are best managed through exclusion by planting hostas in wire mesh baskets buried in the soil to prevent access to the crown. For insects like earwigs and cutworms, simple traps, such as crumpled paper or a rolled-up newspaper placed near the plant, can collect the pests for disposal. Keeping the garden area clean of debris and excessive mulch also removes the moist, dark hiding spots preferred by slugs and earwigs.