Gardeners across the UK are turning to simple homemade sprays to combat caterpillar infestations, which can strip plants of foliage in days. Boxtree caterpillars, now considered Britain's most damaging pest, are at their peak between April and October, according to the RHS. These insects can completely defoliate a hedge or box ball plant in under a week, leaving silvery webbing and dead leaves.
Instead of spending hundreds on chemical pesticides, experts recommend using everyday kitchen ingredients like garlic, chili, and dish soap to create effective repellents. These natural solutions are safe for the environment and gentle on plants.
Potent Natural Spray Recipe
Garden specialists at Sai Nursery have developed a powerful homemade spray using crushed chili, garlic cloves, dishwashing liquid, vegetable oil, and turmeric mixed with water. The mixture should sit for a while before being sprayed generously on both sides of leaves.
According to the experts, "For a potent homemade caterpillar deterrent, combine crushed chili, garlic cloves, dishwashing liquid, vegetable oil, and turmeric with water. Let the mixture sit for a while before spraying it generously on both sides of the leaves." The pungent smell of garlic contains natural compounds that repel caterpillars, while chili irritates soft-bodied insects. Turmeric adds a strong aroma, and vegetable oil coats leaves, making it harder for caterpillars to grip. Dishwashing liquid helps the mixture stick to foliage and insects.
Soapy Spray Solution
The Little Veggie Patch Co recommends a basic soapy spray as an effective caterpillar repellent. Mix 1 tablespoon of biodegradable dishwashing liquid with 1 teaspoon of cooking oil in 1 litre of water. Spray over foliage, especially on the underside of leaves. The mixture keeps for up to one month.
The experts state: "One of the classic sprays in every gardener's toolkit - soapy spray - is great for aphids, whitefly, thrip and caterpillars."
Soapy Garlic Spray
Landscaping specialists Maroochy Sand and Gravel suggest a soapy garlic spray. To make it, combine 500ml of water, 2 tablespoons of garlic powder, and 1 teaspoon of dishwashing liquid in a spray bottle. Shake vigorously to blend. Apply directly to affected plants or on live caterpillars.
The experts explain: "Caterpillars don't like the taste and the smell of garlic so this will deter them to go to another place, other than eating your lovely plants." If the mixture separates, simply shake again before use.
These homemade sprays offer a cost-effective and eco-friendly way to protect gardens from caterpillar damage without harsh chemicals.
