Ask the Plant Doctor! 7 natural ways to manage pests in your garden

Marigolds help to control soil nematodes, which are a common issue in Malaysia’s tropical climate. Photo: Anita Bozic/Pixabay

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What are some of the best natural ways to manage pests without synthetic chemicals, like using beneficial insects or homemade sprays? Which plants/herbs are they suitable for? – Ken Lee

Beneficial insects can be used as nature’s pest control. Ladybirds, praying mantises, lacewings and parasitic wasps prey on common garden pests.

Attract these allies by planting marigolds, cosmos, dill and Thai basil throughout your garden.

Plant-based solutions offer effective pest management. Neem oil, mixed with water and a few drops of soap, serves as an all-purpose insecticide.

Lemongrass tea repels mosquitoes, while chilli pepper spray deters various pests. Apply these to vegetables and ornamentals, but always test a small area first.

Strategic planting enhances pest resistance. Intersperse lemongrass, pandan and citronella to naturally repel insects.

Marigolds help to control soil nematodes, which is a common issue in Malaysia’s tropical climate.

Adapt your gardening practices to minimise pest problems. Rotate crops, water early to prevent fungal growth, and use organic mulch. Regular plant inspection is essential in tropical conditions.

Employ physical barriers for additional protection. Floating row covers, which are lightweight, translucent fabrics draped directly over plants or plant rows, shield crops from insects, while allowing sunlight, air and water to penetrate.

These are particularly useful for protecting seedlings in the tropical climate of Malaysia.

Sticky traps also effectively capture pests; use yellow ones for flying insects and blue for thrips.

Finally, promote biodiversity. A garden with a variety of native plants, water features and undisturbed areas fosters a balanced ecosystem where natural predators thrive, aiding pest control.

Assoc Prof Dr Christopher Teh heads the Department of Land Management, Faculty of Agriculture, Universiti Putra Malaysia. His field of specialty is in soil and water conservation. The views expressed are entirely his own.