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How to Get Rid of Cabbage Worms & Moths: 8 Methods
Pete Ortiz
Last updated:
You spend countless hours preparing and tending to your garden. The expectation is that you will have wonderful veggies for your favorite recipes or to eat raw. There are many common pests that can destroy your garden, however. Cabbage worms are one of those common pests that can cause damage to the garden and destroy your beautiful heads of cabbage.
We do not want that to happen, so we have compiled a few ways to rid your garden of cabbage worms.
The 8 Methods to Get Rid of Cabbage Worms & Moths
1. Row Covers
Row covers are made from insect netting. The netting is used to cover individual plants or propped up with hoop structures to cover raised beds. Row covers can protect plants from insects, frost, and excessive sun.
If the row covers are installed early enough, you can prevent the cabbage moths from ever entering the bed and touching the plants at all. Cabbage worms cannot eat something they can’t get to. Row covers will also protect your cabbage from birds, rabbits, squirrels, and cats.
You can purchase the hoops and netting needed for the size of your raised bed. Clothes pins are effective in keeping the corners tucked and the sides tight. When you need to access the plants, pull the cover off the hoops.
Photo By: Sever180, Shutterstock
2. Plant Red and Purple Cabbage
Fortunately, cabbage worms and other pests are repelled by red and purple vegetables. If you plant red and purple cabbage, you will notice less damage from aphids and cabbage worms than on the green cabbage you planted. The theory is that cabbage worms can hide easily on green cabbage leaves because they blend in. The worms are more noticeable on the red and purple leaves, which makes them easy prey for predators.
Red and purple cabbage leaves along with other blue colored vegetables are rich in anthocyanin. Studies have shown that the flavonoid can be poisonous to caterpillars and larger animals like squirrels.
3. Mixing a Variety of Plants and Companion Planting
To reduce the risk of widespread damage to your crops, create a garden with a variety of plants to attract insects that will benefit your garden and create balance. It will prevent loss and damage from insects that are drawn to the same plant. In other words, do not have all the same plants in one raised bed.
To deter cabbage moths, try planting lavender, thyme, dill, oregano, onions, garlic, and marigolds with your cabbage plants. They are considered companion plants and are known to prevent the pests.
Companion planting can also be used to lure the cabbage worms away from your crop. It is called a “trap crop.” The idea is to plant crops nearby that will attract the moths and worms and keep them off your cabbage plants. As the “trap crop” becomes infested, the plant should be removed from the bed to prevent overpopulation of the pest.
Photo Credit: Bambang F Indarto, Shutterstock
4. Manually Remove the Cabbage Worms
Yes, for some of us, the thought of this makes us squirm, but it is the quickest and easiest way to remove worms from your cabbage. That’s right, fellow gardeners—pick them off and squish them. YUK! This may not be an option for those of you that do not like touching insects or killing them for that matter.
Routing inspections (once or twice a week) will reduce the damage to your plants from cabbage worms. The worms can be found in the center of the plant and on the bottom of the leaves. While holey leaves are an indication of cabbage worms, they will also leave a trail of poop. If you see the poop, you know there are cabbage worms in your garden bed.
Cabbage worms also leave behind cabbage moth eggs. When inspecting the plants, look for yellow or white oblong dots on the underside of the cabbage leaf. You can simply wipe them off and eliminate them.
5. Parasitizers
Parasitizers are like predators; they go after other insects but not in the typical way. For example, a parasitic wasp will lay its eggs on a caterpillar. When the wasp’s eggs hatch, the larvae will feed on the host insect or caterpillar and kill it.
Unlike the wasps we are familiar with, parasitic wasps do not bite or sting. There are starter packs of wasp eggs available to purchase and introduce into your garden.
Once they build a community in your garden, you won’t even know they are there!
Image Credit: galitsin, Shutterstock
6. Cabbage Moth Decoy
Print an online template of a white moth and make your decoy. Place a few of them in your garden to keep cabbage moths at bay. Since cabbage moths are territorial, they will avoid areas that have white butterflies in or around the area.
It is important to put the decoys in your garden as soon as you plant your seeds or as soon as you see a sprout. If you wait, it may be too late.
7. Bacillus Thuringiensis or “Bt”
Bacillus Thuringiensis, or “Bt”, is an ingredient found in organic pesticides. The solution can control cabbage loopers and worms from invading plants like cabbage, broccoli, and kale. It is bacteria that occurs naturally and is found in soil and on leaves.
While “Bt” is not toxic to mammals, including humans, it is toxic to certain insects, like caterpillars. It is toxic to the worms of moths and butterflies and will make them stop eating.
Image Credit: Julio César García, Pixabay
8. Neem Oil Spray
While neem oil will not kill cabbage worms, it can be used as a deterrent for cabbage moths, flies, and mosquitos, so you can avoid getting them in the first place.
Unfortunately, if your garden beds already have cabbage worms, the neem oil will not kill them.
Neem oil is not commonly used for pest control since it will not eliminate or prevent cabbage moths. It is used as a supplemental control method only to help with the problem, not control it.
The plant-based oil should be diluted and sprayed on your plants to control pests like spider mites, mealybugs, scale, aphids, thrips, and white flies. The oil will coat the bodies of the pests, and typically, they will die. Otherwise, it will disrupt feeding and reproduction.
We recommend that you learn about the proper use of neem oil so you don’t do more harm than good.
What are Cabbage Moths and Worms?
Cabbage worms are the velvety green larvae of an adult white butterfly. They have light yellow stripes on their green body. The butterflies are sometimes referred to as small whites or cabbage whites. They can usually be found on broccoli, kale, cauliflower, cabbage, and other members of the brassica family.
The yellow-green caterpillars that are found on cabbage plants are cabbage loopers, which are different from cabbage worms. Cabbage loopers do not have middle legs, and their bodies are loopy and wobbly when they move.
Conclusion
When you are planting your summer garden, it is with the anticipation that the result will be beautiful and fresh garden vegetables. If you do not inspect and treat your plants for pests, you may be disappointed at harvest time. Cabbage worms can infest and destroy plants like cabbage, kale, broccoli, and turnips. So don’t be fooled by those pretty, white butterflies in your garden; they are there to lay their eggs and destroy your garden!
Pete has been working in the trades since high school, where he first developed a passion for woodworking. Over the years, he has developed a keen interest in a wide variety of DIY projects around the home. Fascinated by all sort of tools, Pete loves reading and writing about all the latest gadgets and accessories that hit the market. His other interests include astronomy, hiking, and fishing.
As the founder of House Grail, Pete's primary goal is to help consumers make educated decisions about DIY projects at home, in the garage, and in the garden.