What Is Eating My Cauliflower, Cabbage, and Broccoli Leaves

Caterpillars, especially cabbageworms and cabbage loopers, are common culprits eating cauliflower, cabbage, and broccoli leaves, but flea beetles, slugs, snails, and browsing animals can also cause damage. These vegetables belong to the brassica family and attract many of the same pests. Match the leaf-damage pattern with the pest signs you find before choosing a treatment.

What You See	Likely Cause	Best First Action
Large, irregular holes with dark droppings nearby	Cabbage loopers or imported cabbageworms	Inspect leaf undersides and folds; handpick caterpillars
Thin, translucent “windows” in leaves	Diamondback moth caterpillars	Look closely beneath damaged areas for small, active larvae
Leaves rapidly reduced to veins	Groups of caterpillars, including cross-striped cabbageworms	Search for striped larvae and pest egg clusters
Numerous tiny, round “shot holes”	Flea beetles	Look for jumping beetles; protect cleared seedlings with insect netting
Ragged holes accompanied by slime trails	Slugs or snails	Inspect after dark and remove the pests
A young plant severed near soil level	Cutworms	Search the soil around the stem and remove the caterpillar
Large leaf sections or whole leaves missing	Rabbits, deer, or birds	Look for tracks and browsing evidence; use a physical barrier
Curled leaves with dusty gray-green insect clusters, but no chewing	Cabbage aphids	Dislodge colonies with water; consider labeled insecticidal soap if needed

Identify the Caterpillars Eating Brassica Leaves

Cauliflower, cabbage, and broccoli may produce different edible heads, but their leaves offer similar food for insects. The pests commonly called cabbage “worms” are caterpillars, the feeding stage of butterflies or moths.

Hole shape gives you a starting point, not a definite identification. Body texture, movement, markings, and location are more useful when deciding what is actually present.

Diamondback Moth Caterpillars

Diamondback moth caterpillars reach only 0.5 inches before pupating, yet they are the most serious brassica insect pest in South Carolina, according to Clemson Cooperative Extension. Their importance varies by location, but their small size makes them easy to overlook.

Check the undersides of leaves beneath translucent patches. These caterpillars can scrape away leaf tissue while leaving the upper cuticle intact, creating a windowpane effect.

Gently disturb a suspect caterpillar. Diamondbacks often thrash violently or drop from the leaf on a silk thread, useful clues when the insect otherwise looks like an indistinct green speck.

A diamondback inside a loosely woven cocoon is a pupa and is no longer feeding. Do not mistake these cocoons for actively damaging larvae or use their presence alone as a reason to spray.

Cabbage Loopers

A mature cabbage looper reaches 1.25 to 1.5 inches long and is thicker toward its tail than its head. Watch it crawl: the body arches into a characteristic loop.

If you can examine its underside, look for two pairs of abdominal prolegs, the fleshy gripping legs farther back on the body, rather than the small true legs near the head.

A few large loopers can explain surprisingly heavy leaf loss. One looper causes roughly as much damage as 5 diamondback moth caterpillars, so finding only a handful does not rule them out as the main problem.

Imported Cabbageworms

Imported cabbageworms are fuzzy or velvety green caterpillars that reach around 1 inch long. Their adult form is the familiar white cabbage butterfly; the caterpillar, not the butterfly, chews the leaves.

Their feeding can resemble looper damage, although an imported cabbageworm causes about 2/3 as much damage as a looper in Clemson’s comparison. Use the fuzzy body and crawling movement to distinguish them rather than trying to identify them from holes alone.

Cross-Striped Cabbageworms

Cross-striped cabbageworms have alternating black-and-white stripes across their backs and a yellow stripe running along each side. They reach about 0.75 inches before pupating.

While inspecting leaf undersides, look for clustered eggs as well as caterpillars. Cross-striped cabbageworm moths lay masses of up to 25 eggs, allowing a group of larvae to begin feeding together.

That concentrated feeding can rapidly skeletonize a plant. If one leaf holds several striped caterpillars, inspect the rest of that plant carefully rather than stopping after removing the first visible insect.

How to Stop Pests From Eating Your Brassicas

The best control depends on the pest you find, not simply on how badly the leaf is damaged.

Work from removal and exclusion toward a targeted treatment. A damaged plant does not automatically need an insecticide.

Step 1: Find Evidence of Active Feeding

Lift damaged leaves and examine both surfaces, especially along veins, inside folds, and around the growing center. Caterpillars often blend into the leaves or hide where leaves overlap.
Look for live pests and fresh droppings, also called frass. Check developing heads gently without pulling them apart or damaging the central growing point.
If nothing is visible, examine the soil around the stem and return after dark with a flashlight. Old leaf holes alone do not show that caterpillars are still feeding.

Photographing a suspect insect can help you compare its markings without repeatedly handling it. Include enough of the leaf or stem to show its relative size.

Step 2: Remove Accessible Pests

Handpick visible caterpillars, slugs, and snails, using gloves if preferred. Drop collected pests into a container of soapy water, keeping that water off plants and soil. Crush or wipe away eggs only when you have identified them as pest eggs; not every egg cluster belongs to a leaf-eater.
For aphid colonies, support tender growth and direct a firm stream of water at the insects. Check protected folds afterward, where some aphids may remain.
Finish by inspecting neighboring plants. Dispose of collected pests and removed pest-infested material rather than leaving them beside the bed.

Avoid stripping the plant merely to make it look tidy. Green portions of damaged leaves still help support growth.

Step 3: Exclude Pests From the Cleared Plants

Place insect netting or a suitable row cover over plants after removing visible pests. Support it so developing plants have room to grow, and secure the edges so insects cannot enter underneath.
Inspect beneath the cover and repair gaps. Covering a plant does not eliminate eggs already on its leaves or pests already in the soil.

Brassicas grown for leaves and heads do not need insect pollination before harvest, so exclusion can remain useful through the crop’s development. If animals are browsing the plants, use a sturdy animal barrier rather than relying on lightweight insect fabric.

Step 4: Use a Targeted Treatment Only if Needed

Match a caterpillar treatment to active larvae. Bacillus thuringiensis (Bt), in a formulation labeled for caterpillars on your brassica crop, is a targeted option. It must be eaten and works best against young larvae, so apply it to the feeding surfaces specified by the label. Caterpillar-targeting Bt will not solve an aphid, flea beetle, slug, or animal problem.
Match insecticidal soap to exposed aphids. Insecticidal soap is a contact treatment: the spray must reach the insects. Choose a product labeled for the edible crop, and do not substitute a homemade dish-detergent mixture. Soap formulations and application directions vary by product.
Check broader-spectrum alternatives carefully before buying them. Garden Tech Sevin 5% Dust and Southern Ag Carbaryl 5% Dust are named dust options in Clemson Cooperative Extension’s Table 1, “Insecticides Labeled for Use on Brassica Crops”. Its named malathion options include Gordon’s Malathion 50% and Hi-Yield 55% Malathion Spray. These percentages identify the particular formulations; they are not interchangeable application rates or instructions for mixing a spray. A brand name alone does not establish the active ingredient, approved crop, or current directions.
Confirm the exact use on the current container label. The product must list the crop and target pest. Check its application rate or dilution, required protective equipment, repeat-treatment restrictions, reentry directions, and preharvest interval. Table listings help identify options, but the current product label determines how, or whether, you can use that particular formulation.
Finish with a check, not an automatic repeat application. After the treatment has had its labeled opportunity to work, inspect for surviving pests and fresh feeding before any permitted repeat. Keep people and pets out for the required interval, and record the earliest permitted harvest date.

Concentration, formulation, crop, and product directions all matter.

When the Damage Is Not From Caterpillars

If leaf-chewing caterpillars do not explain the damage, check for slugs, snails, flea beetles, and aphids. Also check collapsed seedlings for cutworms, which are caterpillars that damage stems near soil level.

Slugs and Snails

Slugs and snails can shelter during the day and feed when conditions are darker and damp. Their absence during a sunny inspection does not rule them out.

Search beneath nearby boards, pots, and other hiding places, as well as under low leaves. Slime trails are helpful evidence, but they are not always obvious.

Collect the pests when you find them and remove unnecessary shelters close to the plants. Do not treat them with a caterpillar insecticide; it will not address the cause.

Cutworms

Cutworms are especially worth investigating when a seedling has collapsed rather than simply developed holes. A damaged stem near the soil surface changes the diagnosis.

Gently search around the base of the affected plant and just beneath loose soil. A curled caterpillar may be hiding nearby.

Remove the cutworm. When protecting a replacement seedling, place a sturdy collar around its stem with part of the collar below the soil surface and part above it. Leave room for the stem to expand, and adjust or remove the collar before it constricts growth.

Flea Beetles and Aphids

Flea beetles often jump away when disturbed, so watch the plant before moving its leaves. Young seedlings are more vulnerable to their feeding than established plants with substantial leaf area.

Protection matters most while those plants are small. Inspect transplants before covering them, and do not trap beetles beneath a newly installed cover.

Aphids require a different interpretation. Their waxy gray-green colonies may gather in leaf curls and sheltered growth, where feeding can distort the plant.

Finding aphids on a chewed leaf does not mean the aphids made the holes. They suck plant sap rather than removing chunks of tissue. If both colonies and holes are present, keep looking for a second pest instead of assuming one treatment will solve everything.

How to Confirm Recovery and Prevent More Damage

Judge success by what happens next, not by whether the old leaves look perfect. Missing tissue will not grow back, and existing holes can become more noticeable as a leaf expands.

Look for these signs:

New leaves are developing without fresh feeding damage.
Fresh droppings are no longer accumulating.
Repeated inspections find fewer or no active pests.

If damage continues, identify the surviving pest again. A different pest may have arrived, eggs may have hatched, or the original treatment may not have reached the feeding site. Increasing spray strength is not a substitute for finding the cause.

For prevention, remove spent brassica plants after harvest and manage nearby weedy mustard relatives that can host brassica pests. Avoid unnecessary broad-spectrum insecticide use, which can also kill helpful insects.

For the next planting, inspect transplants before setting them out and install exclusion covers before pests reach the leaves.

Frequently Asked Questions

Will Eaten Cauliflower, Cabbage, or Broccoli Plants Grow Back?

Plants with an intact growing point and enough remaining foliage can continue growing after leaf damage. A seedling severed at the stem or a plant with a destroyed growing center is much less likely to recover normally. Keep usable green leaves, stop the active feeding, and watch for healthy new growth rather than removing every damaged leaf.

What Animal Eats Only Cauliflower Leaves?

Rabbits, deer, and sometimes birds can eat cauliflower leaves while leaving other plants, or the developing head, untouched. Look for tracks, droppings, clipped growth, or evidence of daytime visits. For an individual plant, a rigid wire-mesh cage secured at ground level and roomy enough for growth provides a physical barrier that insect sprays cannot.

Are Broccoli and Cauliflower Leaves Edible?

Yes, broccoli and cauliflower leaves, including the leaves around a broccoli head, are edible. A few insect holes do not make otherwise sound leaves inedible, but discard rotting leaves or produce contaminated by animal droppings. Observe any pesticide label’s harvest restrictions, then wash the leaves thoroughly under running water. Trim tough midribs and add the greens to soup, a stir-fry, or a sauté with olive oil.

What type of vegetables are broccoli and cauliflower?

Broccoli and cauliflower are members of the brassica group. Other brassica crops include collards, kale, cabbage, mustard, and turnips.