Keep Japanese Beetles Out Of Your Garden With An Unexpected Kitchen Staple

Japanese beetles (Popillia japonica) are notorious pests that wreak havoc on garden plants, making them a terror to any gardener. These insects, native to Japan, were accidentally introduced to the United States in the early 20th century and have since become a serious threat to agriculture and horticulture. Additionally, they emit pheromones that attract others to join them in their feeding frenzy, leading to large infestations that can quickly decimate garden plants. Although chemical pesticides are available, they may harm beneficial insects and disrupt the garden's ecosystem. Instead, consider using garlic from your kitchen to concoct a natural insecticide that you can safely spray on your garden plants to deter Japanese beetles from feeding on your garden.

Japanese beetles are voracious feeders with a wide-ranging diet, consuming over 300 different plant species, including roses, grapes, apples, and ornamental plants. Their insatiable appetite leads to extensive damage, as they devastate leaves by devouring the tissue between the veins, leaving plants weakened and vulnerable to diseases.

How to make and apply your own garlic repellent

Making an insecticide from garlic to repel Japanese beetles is a natural and effective method. Not only is it safe for your garden ecosystem, but it's also super affordable and sustainable. According to The Garlic Farm, you'll need a bulb of garlic, a blender or food processor, liquid dish soap, water, and a spray bottle. To begin, peel the garlic cloves and combine them in your blender or food processor with 1 cup of water. (If you don't have a food processor, chop or crush the garlic cloves as best as you can.) Blend for a smooth, garlic-infused liquid, and pour it through a fine mesh strainer or cheesecloth to remove any solid pieces. Mix the strained garlic liquid in a blender again with an additional 3 cups of water and 30 mL of dish soap and let the final solution sit overnight. The soap helps the solution stick to the plants and insects. Finally, pour the garlic insecticide into a spray bottle.

Once you have your garlic repellent ready to go, spray it directly onto the leaves, flowers, and stems of your garden plants affected by Japanese beetles. Pay special attention to the areas where the beetles tend to congregate. Reapply the insecticide every few days — especially after rain — to maintain its effectiveness. Remember to test the spray on a small area of your plants first to ensure they don't have adverse reactions to the mixture. Additionally, avoid spraying good bugs like bees and ladybugs.

Why it works

Using a DIY garlic insecticide works to naturally repel Japanese beetles from your garden due to its strong odor and chemical composition. Garlic contains various sulfur-based compounds, including allicin, which is responsible for its pungent smell. This smell is highly offensive to Japanese beetles and acts as a natural deterrent. When the garlic insecticide is sprayed on garden plants, the potent garlic odor masks the scents released by the plants themselves, making it difficult for the beetles to locate their preferred food sources. The repulsive scent disrupts the beetles' feeding and mating behaviors, discouraging them from congregating and laying eggs in the treated area.

Additionally, garlic's sulfur compounds have natural insecticidal properties that can cause irritation and discomfort to insects, including Japanese beetles. When they come into contact with the garlic-infused liquid, it may deter them from continuing to feed on the plants. Unlike synthetic chemical insecticides, a DIY garlic insecticide is non-toxic to humans, pets, and beneficial insects. It offers an environmentally friendly alternative for gardeners who wish to avoid using harmful chemicals — while still protecting their plants from pest damage.