Gardeners can manage common pests without resorting to chemical sprays, according to advice from Which? Gardening experts. Chemical pesticides can inadvertently harm natural predators that help keep pest populations in check.
One recommended approach is to recognise and encourage natural predators. Ladybird larvae and hoverfly larvae, for example, are effective at consuming aphids and other small pests. Avoiding pesticides helps these beneficial insects thrive.
Physical barriers, such as fine insect-proof mesh like Enviromesh, can protect vegetables from flying pests. The mesh should be installed early, before insects lay eggs, and kept in place until harvest, with edges securely fastened.
Another method involves purchasing biological controls from specialist suppliers. These can include microscopic nematodes or predatory mites that target specific pests without harming plants. Identifying the pest before ordering and following supplier instructions for storage and application are crucial.
Removing potential hiding places can also reduce pest numbers. Slugs often shelter in damp areas like rotting wooden bed edges, and checking under pots, containers, and between plant leaves can help locate and remove pests. A thorough autumn clean-up of greenhouses can prevent pests from overwintering.
Gardeners are also advised to be cautious about social media recommendations. Neem oil, often suggested online, is not authorised for use as a pesticide in the UK due to concerns about its effects on human health.