Green beans, or Phaseolus vulgaris, are widely cultivated vegetables that offer a high-value food source for many organisms, from insects to large mammals. The plant’s appeal stems from its nutritional profile, which includes fiber, water content, and essential micronutrients like Vitamin C, Vitamin K, and Vitamin A. This combination makes the foliage and pods an attractive target for animals seeking sustenance. Gardens represent a dense, easily accessible food supply, naturally drawing local wildlife and insect populations.
Insect and Invertebrate Garden Pests
The smallest consumers of green beans often cause the most distinctive damage to the plants. The Mexican bean beetle, a type of lady beetle, is notorious for its adult and larval stages feeding almost exclusively on bean plants. These pests consume the soft tissue between the leaf veins, usually feeding from the underside of the leaf, which leaves behind a characteristic lacy, skeletonized pattern. Japanese beetles also skeletonize leaves, targeting the tissue between the veins and leaving behind a net-like structure.
Other garden pests employ different feeding strategies. Aphids use piercing-sucking mouthparts to draw sap directly from the leaves, stems, and tender new growth. This sap-sucking activity can cause the leaves to wilt, curl, and become stunted. The insects excrete honeydew, a sticky substance that fosters the growth of sooty mold. Slugs and snails, which are invertebrates, chew large, irregular holes in leaves and pods, often leaving a silvery slime trail as evidence of their nocturnal visits.
Common Small Mammals
Highly adaptable small mammals are frequent raiders of green bean patches, with rabbits, squirrels, and chipmunks being the most prevalent. Rabbits target young plants and seedlings, often eating the tender stems and leaves down to the ground. This damage typically appears as a clean, sharp cut, distinguishing it from the ragged tearing of larger animals. Rabbits prefer to feed during dawn, dusk, and throughout the night.
Squirrels and chipmunks, both diurnal, consume different parts of the plant depending on the season and their needs. Squirrels often chew on mature pods, sometimes stripping the plants of their beans or digging up newly planted seeds. Chipmunks, being smaller, are more likely to nibble on the leaves of seedlings and lower plants, sometimes preferring the protein-rich seeds inside the pod. Identifying the responsible mammal can be challenging, but signs include small footprints or lack of damage high up on pole bean varieties.
Larger Foraging Wildlife
Larger animals inflict more extensive damage to a green bean crop in a single feeding session. White-tailed deer are browsers that consume the tender leaves, stems, and pods, often stripping a row of plants down to bare stalks overnight. Their feeding leaves a ragged edge on the remaining stems because deer lack upper incisor teeth and must twist and pull the vegetation to tear it off. The height of the damage, typically above 24 inches, is a clear sign of their presence.
Groundhogs, also known as woodchucks, are heavy foragers that consume a considerable volume of foliage, especially the lower leaves and pods. Their feeding often results in the uprooting of the entire plant. Raccoons, while omnivorous, may also consume bean pods, particularly toward the end of the season when the beans are maturing. They are less likely to cause the widespread defoliation seen with deer or groundhogs.