The use of plants to deter common garden pests represents a growing area of interest for gardeners seeking environmentally sound management techniques. This approach utilizes the volatile compounds and strong scents produced by certain plant species to create a barrier against unwelcome insects. Strategically integrating these natural defenses offers a sustainable way to protect vulnerable crops from damage.
Understanding Stink Bugs and the Damage They Cause
Stink bugs are identifiable by their characteristic shield shape, typically reaching up to 5/8 inch in length. Color varies significantly by species, from mottled brown and gray to bright green. They all emit a strong, unpleasant odor when threatened, a defense mechanism that gives the pest its common name.
These insects possess piercing-sucking mouthparts, which they use to feed on plant sap from leaves, buds, blossoms, and developing fruit. The feeding results in superficial spots, pits, and dimpling on the surfaces of produce. On tomatoes and peppers, damage appears as cloudy spots and blemishes, with the tissue beneath the skin becoming white, corky, and firm.
In corn, stink bugs feed through the husk, sucking juices from developing kernels, often leaving them shrunken or missing. For crops like peaches, the tissue turns brown and corky at the feeding site, causing the fruit to become distorted as it grows. High infestation levels can severely stunt plant growth, deform fruit, and destroy entire harvests.
Specific Plants Known for Repelling Stink Bugs
A number of plants are recognized for their ability to deter stink bugs primarily due to the strong aromas they release. These repellent effects are linked to volatile organic compounds that interfere with the pest’s ability to locate host plants. The strategy focuses on using highly aromatic species to mask the scent of desirable food crops.
Aromatic Repellents
Specific plants known for their repellent properties include:
- Garlic (Allium sativum): Contains potent sulfurous compounds. The strong odor released by the bulb and foliage is highly offensive to stink bugs, making it an effective barrier when planted nearby.
- Radishes (Raphanus sativus): Their pungent nature is thought to deter pests.
- Catnip (Nepeta cataria): Contains nepetalactone, a compound intensely disliked by numerous insects.
- Mint (Mentha species) and Lavender (Lavandula): These herbs contain heavy aromatic oils that make the surrounding area less inviting for pests.
- French Marigolds (Tagetes patula): Their powerful scent helps to confuse and repel various garden invaders.
- Nasturtiums (Tropaeolum) and Chrysanthemums (Chrysanthemum species): These flowering plants are noted for repellent properties due to specific chemicals within their foliage and flowers.
Strategies for Using Repellent Plants in the Garden
Implementing repellent plants effectively relies on strategic placement to maximize the dispersal of their active compounds. One of the most common methods is companion planting, which involves interspersing the deterrent plants directly among the vulnerable crops. Planting catnip or basil close to tomatoes, peppers, or beans helps to mask the scent of the target crops, making them harder for stink bugs to find.
A second strategy involves creating a planted barrier or border around the entire vegetable patch. High-density planting of species like marigolds or garlic along the perimeter of the garden can establish a protective aromatic wall. This border is designed to intercept and divert pests before they reach the main growing area.
The effectiveness of these plants can be further enhanced by incorporating them into homemade botanical sprays or teas. For example, a concentrated mixture of crushed garlic or mint leaves can be steeped and strained to create a liquid that is then applied directly to the foliage of vulnerable plants. This provides an immediate, though temporary, layer of protection by coating the crops with the repellent aroma.
The continuous presence of the repellent plant is important, and planting density should be sufficient to ensure the strong odors are consistently emitted into the air circulation of the garden. By combining perimeter planting with interplanting and occasional applications of botanical preparations, gardeners can establish a layered defense system to reduce stink bug pressure.