What Is Eating My Cabbage

If you’re finding holes in your cabbage leaves, you’re probably asking, “what is eating my cabbage?” It’s a common garden pest problem that can feel frustrating, but identifying the culprit is the first step to a healthy crop. Let’s look at the usual suspects and how to send them packing.

Several insects find cabbage as tasty as we do. The damage they cause gives you clues. Large, irregular holes often point to bigger pests like caterpillars or beetles. Skeletonized leaves, where only the veins remain, are a classic sign of certain beetles. Tiny shot holes might be from flea beetles, and slimy trails are a dead giveaway for slugs or snails.

Cabbage Worms: The Green Munchers

The most common offenders are cabbage worms. These are the larvae of white butterflies you see fluttering around your garden. They blend in perfectly, being velvety green, and they chew large holes from the outer leaves inward.

Signs: Greenish-brown frass (droppings) on leaves. Large, ragged holes.
Prevention: Use floating row covers from the day you plant to block butterflies from laying eggs.
Control: Handpick them off. Apply Bacillus thuringiensis (Bt), a natural bacterial spray that specifically targets caterpillars.

Cabbage Loopers: The Inchworm Imposters

Loopers are pale green caterpillars that move by arching their backs. They are the larvae of a brown moth. They cause damage very similar to cabbage worms, often feeding together.

Signs: Large holes and lots of frass. Look for their distinctive looping movement.
Prevention: Row covers are again your best defense.
Control: Bt is also effective against loopers. Neem oil can help disrupt their feeding.

Diamondback Moth Larvae: The Small But Mighty

These are smaller, yellowish-green caterpillars that wiggle rapidly when disturbed. The adult is a small, gray moth. They create windows in leaves by eating the tissue between the veins.

Signs: Shot-hole or window-pane damage on younger leaves. They can be very numerous.
Prevention: Good garden sanitation in fall to remove overwintering pupae.
Control: Spinosad, a natural substance, is very effective. Bt can work if applied thoroughly.

Slugs and Snails: The Nighttime Slimers

These mollusks feed at night and on cloudy days. They leave irregular holes and a telltale silvery slime trail on leaves and soil.

Signs: Ragged holes with smooth edges and slime trails.
Prevention: Remove hiding spots like boards and dense weeds. Water in the morning so soil is dry by evening.
Control: Set traps using shallow dishes of beer. Handpick at night with a flashlight. Create barriers with diatomaceous earth (reapply after rain).

Flea Beetles: The Jumping Specks

These tiny, shiny black beetles jump like fleas when disturbed. They attack young plants most severely, peppering leaves with many small holes.

Signs: Numerous small, round holes that look like shotgun pellets hit the leaf.
Prevention: Use row covers until plants are established. Plant trap crops like radishes nearby.
Control: Diatomaceous earth dusted on leaves. Sticky traps can catch some. Healthy, fast-growing plants often outgrow the damage.

Cabbage Root Maggots: The Hidden Threat

The real problem here is the larvae, which are white maggots that feed on roots. Plants will wilt, look stunted, and have a blueish tint. You might see the adult flies, which look like houseflies, near the soil.

Signs: Wilting plants that don’t recover with water. Tunnels in roots. Plants easily pulled from soil.
Prevention: Use cabbage collars (felt or cardboard circles) placed around the stem at soil level to prevent egg-laying.
Control: Beneficial nematodes applied to the soil will attack the maggots. Remove and destroy infested plants.

Aphids: The Sap-Sucking Crowd

These tiny, soft-bodied insects cluster on the undersides of leaves and stems. They suck plant juices, causing leaves to curl and yellow. They also excrete honeydew, which leads to sooty mold.

Signs: Clusters of green, gray, or black bugs on new growth. Sticky leaves and distorted growth.
Prevention: Encourage ladybugs and lacewings, which are natural predators.
Control: A strong blast of water from the hose knocks them off. Insecticidal soap or neem oil sprays are effective for heavy infestations.

Cutworms: The Stem Cutters

These caterpillars hide in the soil by day and emerge at night to chew through young seedling stems at ground level, felling the whole plant.

Signs: Healthy seedling found cut off at the base and laying on the soil.
Prevention: Place a collar (like a paper cup with the bottom cut out) around each transplant, pushing it an inch into the soil.
Control: Search in the soil around a damaged plant at dawn; handpick and destroy. Diatomaceous earth around stems can deter them.

How to Protect Your Cabbage Patch

A good defense uses multiple strategies. Start with healthy soil and strong transplants. Rotate your crops each year so pests can’t build up in one spot. Interplanting cabbages with strong-smelling herbs like thyme, rosemary, or mint can confuse some pests. Regularly inspect the undersides of leaves—that’s where most trouble starts.

Step-by-Step: A Weekly Cabbage Checkup

Grab a bucket of soapy water for any pests you find.
Check the undersides of 5-6 outer leaves on different plants.
Look for eggs (yellow dots), tiny caterpillars, or aphid clusters.
Examine the base of the stem for signs of wilting or damage.
Remove any badly damaged leaves and drop them in the bucket.
Handpick any visible pests into the bucket.
Apply organic controls like Bt or neem oil if you see active feeding, following label instructions.

Choosing the Right Organic Spray

Not all sprays work on all pests. Here’s a quick guide:

Bacillus thuringiensis (Bt): For caterpillars only (cabbage worms, loopers). Safe for other insects.
Neem Oil: Works against aphids, beetles, and loopers by disrupting feeding. It’s a mild fungicide too.
Insecticidal Soap: Best for soft-bodied insects like aphids. Must contact the pest directly.
Spinosad: Effective against caterpillars, thrips, and some beetles. Still toxic to bees if wet, so spray at dusk.

When to Take Action

Don’t panic at the first hole. A healthy cabbage plant can loose a few outer leaves and still produce a great head. The threshold for action is when you see active pests increasing or when damage is moving quickly to the inner, younger leaves. The goal is management, not total eradication—a few pests feed the beneficial insects.

Encouraging Natural Predators

Your best allies are already out there. Plant nectar-rich flowers like alyssum, dill, and yarrow to attract parasitic wasps that target caterpillars. Provide habitat for birds, who eat tons of insects. Tolerate a few pests, as they are the food that keeps your predator population in your garden.

FAQ: Cabbage Pest Problems

What’s making holes in my cabbage leaves?
This is most often caused by caterpillars (like cabbage worms), slugs, or beetles. The size and shape of the hole gives you a clue.

How do I keep bugs from eating my cabbage plants?
Use physical barriers like floating row covers at planting. Check plants regularly and handpick pests. Encourage natural predators and use targeted organic sprays when needed.

What can I spray on my cabbage for bugs?
Organic options include Bt for caterpillars, insecticidal soap for aphids, and neem oil for a broader range. Always follow the label directions carefully.

Are cabbage worms harmful to humans if eaten?
While unappetizing, they are not poisonous. However, always thoroughly wash your produce and soak heads in salt water to dislodge any hidden caterpillars or their frass.

Why do my cabbages keep getting eaten?
Pests may be overwintering in your garden debris. Practice crop rotation and fall cleanup. Consistent, weekly monitoring is key to catching problems early before they get out of hand. Sometimes, the weather just creates a perfect year for a certain pest, so persistance is your best tool.