How to Get Rid of Cabbage Aphids | Quick Guide to Control Cabbage Aphids

Cabbage aphids (Brevicoryne brassicae) can severely damage young crops in hot, dry climates. Luckily, their interests are confined only to plants in the brassica family—like cabbage, broccoli, and cauliflower—and wet or moderate climates tend to control their growth. Left unchecked, however, they can easily ruin a crop.

What are cabbage aphids?

Cabbage aphids, sometimes called mealy aphids, are small white bugs that feed on brassica crops in large numbers. Like the common aphid, they feed on the sap of a plant, which means they can do damage to nearly any exposed part of your crop.

Symptoms of a cabbage aphid infestation

Cabbage aphids make themselves known in much the same way that regular aphids do. They are usually a whitish-grey color but can also appear black. They group together in thick clusters to feed.

If you miss the cabbage aphids themselves, your plant will let you know that it’s under attack in several ways.

Leaves

Cabbage aphid infestations will result in yellow or white leaves. Oftentimes, the leaves also curl or become otherwise misshapen.

Stunted plant growth

Aphid-infested brassicas will typically grow slowly or incompletely. Their edible heads—like the sprouts on a brussels sprout plant—may appear damaged, stunted, or sickly.

How to cure a cabbage aphid infestation

Unfortunately, once cabbage aphids have appeared, they can be more determined to hold their ground than other aphid types.

Organic methods

One of the best ways to control them is by introducing (or allowing) aphid predators to control their populations. These include:

• Ladybugs (lady beetles): These pretty bugs can eat 50 or more aphids per day and can also control other unwanted pests. Ladybugs are attracted by dill and marigolds.
• Lacewings: Both the brown and green varieties can be helpful in controlling aphid populations. Draw them in with dill or fennel.

Some of the more popular organic aphid control methods may be effective on cabbage aphids. Try:

• Cool blasts of water: Some aphid colonies won’t climb back on a plant once they’ve been dislodged, so a forced exit may be all they need to move along.
• A coating of flour: Like regular aphids, cabbage aphids may be deterred from eating your plants if they’re covered in flour. This is because baking flour gives them severe digestive issues.

Non-organic methods

Cabbage aphids can be persistent, so some people prefer to go the non-organic (insecticidal) route.

1. Conventional insecticides geared toward the affected plant (check the insecticide label) are typically the most fool-proof but hotly debated method. Most can be sprayed 2-3 times on each plant, but follow directions carefully: you may have to wait days to weeks before eating a sprayed plant.
2. Dish soap: A dish soap and water combination can be spread across the leaves of the plants to kill aphid populations. This mixture is commonly called “insecticidal soap.”

Prevention of future infestations

Of course, the best way to control aphids is to keep them from showing up in the first place. If you’ve had a cabbage aphid infestation, remove all affected plants at the end of the season (and don’t add them to your compost—remove them from your property altogether). Cabbage aphids can overwinter, so keeping old plants around is inviting a cold-weather guest.