The Most Common Cabbage Pests & How to Stop Them
You walk into the garden feeling proud of your cabbages… And then suddenly, holes everywhere, slimy trails, curled leaves, tiny green caterpillars hiding deep inside the heads, and aphids having a full family reunion underneath the leaves 😅 Honestly, growing cabbages without pests is almost impossible. If you grow brassicas long enough, something will arrive for dinner.
The good news? Most cabbage pests can absolutely be managed naturally once you know what you’re looking for.
Aphids
Aphids are one of the most common pests found on cabbages during the cooler months. These tiny soft-bodied insects usually gather underneath leaves, around stems, and inside tight new growth. They may be green, grey, black, or even white depending on the species. One of the first signs is often curled leaves, sticky residue, or ants crawling all over the plant. Those ants are usually there because aphids produce a sugary substance called honeydew.
Aphids tend to explode when plants are stressed, airflow is poor, or there is too much soft new growth caused by high nitrogen feeding. Overcrowded gardens also make the problem worse.
The best way to prevent aphids is by regularly checking underneath leaves, improving airflow between plants, avoiding overfeeding, and encouraging beneficial insects like ladybirds into the garden. Flowers like alyssum and marigolds help attract natural predators.
If the infestation is small, spraying the plant with a strong jet of water can often remove many of them. For bigger infestations, neem oil, Pyrol, or a homemade garlic and chilli spray works very well. Always spray in the evening to avoid harming pollinators and to prevent leaf burn.
Cabbage Loopers & Caterpillars
If you are finding holes all through your cabbage leaves along with little green droppings, you most likely have cabbage loopers or caterpillars. These pests come from the white cabbage butterflies fluttering around the garden. Beautiful? Yes. Destructive? Absolutely 😅
The butterflies lay tiny yellow eggs underneath brassica leaves, and once the caterpillars hatch, they can destroy a cabbage very quickly. They especially love cabbage, broccoli, cauliflower, kale, and Brussels sprouts. One of the best forms of prevention is simply keeping butterflies away from your plants altogether. In our garden, we use hoop tunnels with insect netting over brassicas, and honestly, it has made one of the biggest differences.
Checking underneath leaves regularly and squashing eggs early helps stop infestations before they start. Handpicking caterpillars is still one of the most effective methods. Organic sprays like neem oil, or Pyrol can also help when infestations become severe.
Cutworms
Cutworms are sneaky little pests that hide in the soil during the day and feed at night. You often only notice them after waking up to perfectly healthy seedlings lying flat on the soil with their stems cut clean through. They are especially common in newly prepared beds, weedy areas, or heavily mulched gardens where they have places to hide.
To prevent cutworms, try keeping mulch slightly away from tender seedling stems and clear weeds before planting. One of the easiest tricks is placing toilet roll tubes or cardboard collars around young seedlings for protection. If you suspect cutworms, go outside at night with a torch and check around the base of your plants. You can often find them curled up near the stems.
Slugs & Snails
Winter gardens and slugs go hand in hand 😅 Cool wet weather creates perfect conditions for slugs and snails, and they absolutely love young cabbage leaves and seedlings. You’ll usually notice irregular holes, slime trails, or seedlings disappearing overnight.
They thrive in damp gardens with lots of hiding places like thick mulch, wood, rocks, or overcrowded beds. Improving airflow, watering earlier in the day, and reducing overly damp hiding spaces can help reduce numbers. Night inspections with a torch are surprisingly effective, especially after rain.
Beer traps remain a favourite natural option for many gardeners. In our garden, Ferramol has also worked very well and is one of the safer slug controls for pets, birds, and wildlife.
Whiteflies
Whiteflies are tiny white flying insects usually found underneath cabbage leaves. If you brush the plant and a little white cloud rises up, you likely have whiteflies. They suck sap from the leaves, weakening the plant and often leaving behind a sticky residue. Heavy infestations can cause yellowing leaves and poor growth.
Whiteflies love warm protected areas, overcrowded gardens, and stressed plants with poor airflow. Good spacing between plants is one of the best preventative measures. Removing badly infected leaves early also helps slow infestations down before they spread.
Neem oil, insecticidal soaps, and Pyrol can all help control whiteflies, although repeat treatments are often needed because the eggs hatch in cycles.
The Secret to Healthy Cabbages? Prevention.
Honestly, the biggest lesson I’ve learned with brassicas is that prevention matters far more than cure. Regular inspections, healthy soil, good airflow, hoop tunnels, insect netting, companion flowers, and catching problems early make a massive difference.
In our garden we mainly use electrical conduit hoops with insect netting over brassicas. It helps protect against birds, butterflies, and many common pests while still allowing us to rotate crops easily. And remember… even experienced gardeners lose cabbages sometimes 😅
That’s gardening. A slightly holey homegrown cabbage still tastes far better than anything from the shops.
For our members, don’t forget that under the Resources section on the website, we have downloadable guides and growing resources available to help you grow your winter vegetables successfully this season
From my garden to yours
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