How to Get Rid of Cabbage Worms

Cabbage worms can be a real nuisance in the garden, munching their way through your healthy cabbage crops and leaving unsightly holes in the leaves. Getting rid of them takes some work, but it’s worth it to protect your harvest. Here are the most effective methods for controlling cabbage worms organically and preventing future infestations.

Identify the Pest

The first step is identifying the type of worm causing damage. There are a few common cabbage worms:

  • Imported cabbageworms – Velvety green worms that blend into the leaves. They turn into white butterflies.
  • Cabbage loopers – Light green worms with white stripes that “loop” as they crawl. They turn into brown moths.
  • Diamondback moths – Small gray or brown moths that lay tiny worms on leaves. The worms are light green.

Check the undersides of leaves for worms, eggs, and the telltale signs of feeding like holes or chewed edges on leaves. Knowing the type of worm helps choose the best organic treatment.

Remove Them Manually

One of the safest and most effective ways to get rid of cabbage worms is to simply pick them off by hand. Check plants thoroughly every few days, especially the undersides of leaves where worms like to hide. Crush any worms you find to prevent them from returning.

You can also knock them off into a bucket of soapy water which will kill them. Be diligent, as manual removal must be done repeatedly to keep populations down. But it avoids using chemical pesticides.

Apply Organic Sprays

Organic sprays can be used to safely kill cabbage worms and deter future infestations:

  • Bt (Bacillus thuringiensis) – This natural bacteria-based spray kills caterpillars when they ingest it but is safe for people and beneficial insects. Reapply after rain.
  • Spinosad – Made from a soil organism, this spray is also toxic to caterpillars but won’t harm other creatures. It must be reapplied frequently.
  • Neem oil – Extracted from the neem tree, this oil repels and disrupts the growth of pests. It’s safe to use up to the day of harvest.
  • Pyrethrin – This plant-based insecticide kills larvae but can also harm bees and other beneficials. Use cautiously and only early in the morning or evening when pollinators are less active.

Follow label instructions for dosage and reapplication guidelines when using organic sprays. Target the undersides of leaves and reapply after rain. Combining sprays can improve efficacy.

Protect Plants with Row Covers

Row covers create a physical barrier to prevent cabbage moths from reaching plants and laying eggs. Cover seedlings with lightweight fabric row covers after planting, securing the edges with stakes or soil. Remove covers when plants start flowering so pollinators can access them.

For greater effectiveness, use fine mesh netting instead of row cloth to exclude the smallest insects. Just be sure to allow airflow and ventilation to avoid overheating plants.

Attract Natural Predators

Encouraging beneficial insects that prey on cabbage worms can help control populations:

  • Plant flowers like daisies, marigolds, and asters which attract hoverflies and parasitic wasps that eat worms.
  • Avoid pesticides so populations of lady beetles, lacewings, praying mantises and other predators aren’t harmed.
  • Create a DIY wasp nest by filling a clay pot with straw and placing it near the garden to provide wasp habitat.

Take steps to avoid harming natural enemies of cabbage worms to maintain balance with pests in the garden.

Practice Crop Rotation

Rotating crops in different areas of the garden each year helps disrupt the life cycle of cabbage worms. Don’t plant cabbage or its relatives like broccoli, kale and Brussels sprouts in the same spot two years in a row.

This prevents a buildup of worm eggs and larvae in the soil so new plantings are less prone to infestation. Include areas of cover crops or flowers in the rotation to suppress pests.

Keep Garden Areas Clean

Good sanitation in the garden also helps control cabbage worms. Clear away plant debris after harvest which may harbor overwintering pupae. Pull out spent plants and fallen leaves where moths like to lay eggs.

Keep the garden free of weeds, especially mustard family weeds, that provide an alternative food source for the worms. A clean garden environment reduces breeding opportunities.

Time Plantings Carefully

In some climates, cabbage worms are worse during spring and fall. You may be able to avoid peak activity periods by timing plantings for later summer when pest pressure is lower.

Plant as early as possible in spring so plants are grown before worms become active. Similarly, very late summer or early fall plantings may reach maturity before worms thrive again in cooler weather. Check your local Cooperative Extension for the best planting dates.

Use Physical Barriers

Collars made from cardboard or other materials can be placed around cabbage stems or under leaf lettuce to prevent worms from reaching the leaves and heads. The collars should be about 3 inches high and snug to the ground.

Floating row covers (see above) can be applied just to the plants that are under attack instead of the whole crop to conserve materials. Support covers above plants with hoops to keep fabrics from touching leaves.

Grow Resistant Varieties

Plant varieties of cabbage, broccoli and other brassicas specially bred to be resistant to worms and cabbage moths. Good options include:

  • Cabbage – Tastie, Cheers, Amendment, Platinum Dynasty
  • Broccoli – Arcadia, Brigadier, Colonel, Packman
  • Cauliflower – Cheddar, Amber Castle, Ravella, Lucky
  • Brussels sprouts – Jade Cross E, Prince Marvel, Franklin

Check with your local nursery to find resistant varieties best suited for your climate and conditions. Mixing in some hardy varieties helps reduce pest impacts.


Cabbage worms can do a number on backyard vegetable crops but they don’t have to devastate your harvest. Start with preventive measures like timing plantings carefully and rotating crops. It’s also essential to frequently monitor for worms and remove them by hand as soon as spotted. Applying row covers, organic sprays and encouraging natural predators can provide additional protection. With a combination of diligent management methods, you can successfully keep cabbage worms under control.

Frequently Asked Questions About Controlling Cabbage Worms

What are signs of cabbage worms?

Look for ragged holes in leaves, sections of leaves eaten away, cabbage heads with tunnels bored into them, green worm-like caterpillars on plants, and white butterflies hovering around plants. Droppings may also be visible on leaves.

What is the best organic spray for cabbage worms?

Bt (Bacillus thuringiensis) is one of the most effective and safe organic sprays for controlling cabbage worms. It contains a bacterium toxic to caterpillars but harmless to people and beneficial insects. Other good options are spinosad and neem oil.

Are cabbage worms toxic?

Eating cabbage worms is not toxic to humans, though they obviously don’t taste good! Thoroughly washing cabbage heads removes any worms or frass. The worms may eat large amounts of leaf material but this won’t pose any risks of toxicity when consumed after normal washing.

What eats cabbage worms naturally?

Helpful predators that feast on cabbage worms include green lacewings, ground beetles, parasitic wasps, praying mantises, ladybugs, and birds like chickadees. Attract these beneficial insects by planting nectar-producing flowers and avoiding pesticides. Chickens can also help control cabbage worms.

Should I just pull off and kill cabbage worms by hand?

Handpicking worms is highly effective for small gardens, especially if done repeatedly. Crush or drop the worms into soapy water to be sure they don’t return to plants. Combining hand removal with other organic controls like Bt spray gives the best control.

Key Takeaways on Eliminating Cabbage Worms:

  • Identify whether imported cabbageworms, cabbage loopers or diamondback moths are infesting plants. Look for caterpillars and signs of feeding.
  • Manually remove worms from plants by handpicking or knocking them into soapy water. Be thorough and repeat often.
  • Make organic sprays from Bt, spinosad, neem oil or pyrethrin to kill larvae.
  • Cover plants with row cloth fabric to exclude moths from laying eggs.
  • Attract beneficial insects like wasps, lacewings and ladybugs to act as natural predators.
  • Rotate brassica crops to different areas of the garden each year to disrupt pest cycles.
  • Time plantings to avoid peak activity periods for cabbage worms in spring and fall.
  • Grow resistant cabbage, broccoli and cauliflower varieties less prone to worms.
  • Keep the garden free of debris that can shelter overwintering pupae.

Following an integrated pest management approach using multiple organic control methods is the best way to get rid of cabbage worms and protect your crops. With persistence and patience, you can outsmart these common garden pests.