How To Physically Stop Cabbage White Butterflies
Use Netting Or Fleece To Block Egg Laying
One way to provide instant protection is to grow your brassicas under a material which the butterflies cannot reach. This can be something as simple as horticultural fleece, insect netting such as environment, or a fine net, such as our butterfly netting. You should regularly check that your plants haven’t grown tall enough to touch the net – if they do, the butterflies may still be able to lay their eggs.
Our Horticultural Fleece is a good option as it has multiple uses throughout the year, offering great value for money.
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It will provide complete protection for your plants from Cabbage Whites while still allowing water and air to pass through. The material is 2 metres wide and available by the metre. Make sure it’s well anchored – leaving gaps around the edges can allow butterflies in. |
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Use Fine Insect Mesh To Keep Out Pests
Veggiemesh is a superfine nylon mesh that helps prevent damage from cabbage whites, carrot flies, aphids and other pests.
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This mesh lets your crops breathe and take in natural rainwater while keeping pests at bay. At 1.8 metres wide and sold by length, it’s lightweight and easy to drape directly over plants or across a support frame. Anchor securely to avoid any access points for insects. |
Use UV-Stabilised Butterfly Netting For Long-Term Control
Butterfly Netting is a strong, moulded black plastic net, UV-stabilised for extended outdoor use – it should last at least 5 years.
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This netting is ideal for protecting against cabbage white butterflies but not fine enough for smaller pests like aphids or carrot flies. It’s a good solution for large garden areas as you can purchase the 2.6m wide material in any length you need. |
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Biological Control For Cabbage White Caterpillars
Use Nematodes To Control Caterpillars Organically
If you don’t want to use physical netting, Nemasys Fruit and Veg Nematodes Protection is an organic alternative. It uses a mix of nematode species to target a wide range of pests, including cabbage white caterpillars. One application treats up to 60m² for under £10.
To be effective, the spray must make direct contact with the pest – any caterpillars not sprayed will not be affected.
Additional Natural Methods To Control Cabbage Whites
Grow Sacrificial 'Magnet' Plants
You can plant ‘magnet’ crops like nasturtiums in a separate area to lure butterflies away from your brassicas. The caterpillars can then feed on these decoy plants. However, there's a risk you might end up attracting even more butterflies to your garden.
Attract Natural Caterpillar Predators
Encourage predators such as birds, parasitoid wasps and social wasps. Herbs like dill, fennel, coriander, or Queen Anne’s lace can help attract wasps. Parasitoid wasps don’t sting, while social wasps only sting if disturbed.
Be aware that caterpillars full of mustard oil from feeding on brassicas can be unpalatable, and some birds may avoid them.
Pesticide Advice For Cabbage White Caterpillars
When And How To Use Pesticides Safely
Both organic and synthetic pesticides can be used to manage cabbage white caterpillars. However, multiple treatments are often required for effectiveness.
Always ensure the product is approved for the specific crop you're treating and follow any harvest interval guidance. Choose natural ingredients like pyrethrum whenever possible, and check labels to avoid harming beneficial insects such as bees.
Check For Pupae To Reduce Future Outbreaks
After feeding, caterpillars will seek out sheltered areas—shed walls, fences, tree bark—to pupate. In summer, this stage lasts around two weeks; in winter, up to eight. Inspect and remove any you find to reduce future infestations.