8 Things To Do If You Have Cabbage Worms In Your Garden

Keep Cabbage Worms Out Of Your Garden

If you talk to any experienced gardener and mention the words cabbage worms they are likely to shudder. These small but mighty creatures can do extreme damage to any garden. Getting rid of them can be a little tricky as they multiply quickly but there are some proven techniques that will do the job.

Planting mustard plants and purple cabbage, using row covers, and even handpicking cabbage worm eggs and adults off plants, are all strategies that work to control cabbage worms and get them out of your garden.

While cabbage worms can be a frustrating nuisance when gardening, don’t let them keep you from planting the vegetable garden of your dreams since there are things you can do to protect your plants. 

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How to Identify if You Have Cabbage Worms

cabbage caterpillar (cabbage worm) isolated on white background

Different pests respond differently to treatments so it is helpful to make sure you are confident that what is eating your plants is indeed cabbage worms.

The good news is that there are some distinct characteristics to help identify cabbage worms such as the color and shape of their eggs as well as the appearance of the adult worms. 

According to researchers in the entomology department at the University of Kentucky, identifying cabbage worms early can help prevent major damage from occurring to crops.

Finding Eggs Means Cabbage Worms Will Hatch Soon 

One of the telltale signs of cabbage worms is finding eggs on the underside of the leaves of a cabbage plant.

While some insects lay eggs in clusters cabbage worms do not, which is a helpful feature in identifying the first stage of their life cycle.

Their eggs tend to be oval in shape with pale yellow coloring.

Cabbage Worms Start On The Back Of Leaves

Cabbage worms start as eggs on the back of leaves which turn into worms and then finally into cabbage white butterflies.

If you notice small white butterflies that can almost look like moths circling your garden, they are likely laying eggs throughout your plant beds. 

If you have seen the eggs on the underside of the leaves or the cabbage whites flying around, then you will eventually spot the cabbage worms themselves. Once cabbage worms hatch they have a distinct appearance.

Cabbage Worm or Caterpillar on Vegetable plants.

Cabbage worms are green with light yellow stripes on their sides and the eggs they lay are light yellow with an oval shape.

Why Are Cabbage Worms Attracted to Your Garden Anyway?

If you are an avid vegetable gardener or grow crops, you are likely familiar with these light green crawling critters but may not know what works best to help avoid them.

Before finding what works to help get rid of cabbage worms, it can be helpful to understand what attracts them to your garden in the first place. These critters love to eat and eat they will!

You can often tell you have an infestation if you start noticing holes in the leaves of your cabbage plants. They don’t necessarily eat the entire leaf but instead leave a shredded trail of leaf behind after their meal, if you notice an infestation call a professional.

Cabbage Worms LOVE Brassica Plants 

There is a specific type of plant that cabbage worms are attracted to known as the brassica family of plants. This group of plants includes common vegetables that are planted in vegetable gardens such as broccoli, kale, and cabbage.

Cabbage worms basically spend their whole lives attached to plants. They lay their eggs on the underside of leaves of brassica plants and then when they hatch they spend time eating those same plants. 

The Brassica plant family is an ideal host for cabbage worms as they lay their eggs on the underside of the leaves and then once they hatch they don’t have to move to eat to survive.

They start at the very center of the plant and work their way out toward the leaves. 

Believe it or not, even though we humans are divided on whether we like kale or not, there are so many insects that love it! For more in-depth info about these kale-loving insects and cabbage worms head on over to our article about insects that love kale!

It Is Important to Act Quickly Once You See Cabbage Worms

Because the life cycle of a cabbageworm is short, it is important to work to remove them as soon as you spot them in your garden.

Cabbage worms have been known to eat multiple leaves off of cabbage plants in less than a day. This means that the damage they cause happens at a rapid pace.

8 Things You Should Do If You Find Cabbage Worms In Your Garden

While cabbage worms can pop up quickly and they are known for eating a large amount in a few short weeks, the good news is that there are different tricks to getting rid of these hungry creatures.

It may take some trial and error to figure out what works best in your garden, but luckily there are multiple options to get rid of these pesky critters.

These eight tips below are some of the most efficient and effective tips for what to do when you spot the dreaded cabbage worm.

Tip #1: Hand Pick the Eggs and Worms Off the Plants

It may not be your favorite gardening activity, but one of the most effective and guaranteed ways to get rid of cabbage worms is to manually remove them yourself. Make sure to wear gloves!

Keep in mind that you will need to be looking for both the worms and the eggs as you work to rid your plants of the worms. 

While this method is effective, it can also be challenging as cabbage worms are sneaky. They tend to lay their eggs and start feeding in the very center of the plant so it is important to be thorough when examining each cabbage plant as these critters are good at hiding. 

Also, be aware that sometimes cabbage worm eggs and ladybug eggs can look similar – ladybug eggs tend to be in clusters and you will want to leave those alone as they can be helpful to gardens.

Tip #2: Bring in Natural Predators to Eliminate Cabbage Worms

Want to know who loves cabbage worms? Chickens and ducks. That’s right, these farm animals are a great option to help rid your garden or crops of cabbage worms. Plus they are adorable to have around your yard and can be fun farm animals to take care of. 

However, when using this elimination method you will likely need to stay close by as they may also try and sneak in a few of the plants here and there.

Other common predators of the cabbageworm are parasitic wasps and yellow jackets. Planting flowers that attract these flying insects such as sunflowers or daisies is another helpful technique to get rid of the unwanted cabbage worm.

For more ways to find out how to attract wasps, check out our article about the things that attract wasps to your space. Not that we want to attract wasps, but, if you’re having a cabbageworm problem – it may be a solution for you if you’re garden is a ways away from your actual home.

Tip #3: Grow Colorful Plants to Deter Cabbage Worms

Purple green ornamental cabbage in the garden

One of the defense mechanisms cabbage worms use against predators is camouflage. So one technique that helps keep cabbage worms at bay is to plant purple cabbage as they are less interested in eating from that particular plant. 

There is also some research that shows that anthocyanin, the antioxidant that makes dark vegetables good for humans, is actually not so good for cabbage worms which is one of the reasons they stay away from purple cabbage.

Tip #4: Use Trap Plants to Catch Cabbage Worms

Trap plants are another method that gardeners have found to be sufficient in keeping a cabbage worm infestation under control. Wondering what in the world a trap plant is?

Well, its name explains exactly what it does. Using a trap plant simply means planting a specific type of plant that a certain insect is attracted to. 

Once the majority of the insects take over those plants you trap them within those plants in turn protecting the plants you don’t want them destroying. 

Mustard Plants Make Perfect Cabbage Worm Trap Plants

For cabbage worms, the best plant to use to trap them is a mustard plant. 

These crawling pests love mustard plants and will flock to the leaves.

Once they are on the plant, you can simply remove the mustard plant completely with the worms still attached leaving your garden free and clear. 

Tip #5: Use BT to Spray Your Plants

Many gardeners hesitate to use sprays on their plants as they want to protect both their plants and the earth. The good news is that there are some sprays out there that can help get rid of insects while still being safe for plants, humans, and the environment. 

BT spray is a popular choice among gardeners for getting rid of cabbage worms.

BT stands for Bacillus Thuringiensis and it is a naturally occurring element within the soil which is what makes it safe for humans but helps get rid of cabbage worms.

Benefits of BT Spray

This BT Caterpillar Control Spray is a popular choice as it has been shown to be both effective and non-toxic to humans and animals.

One thing to note is that the spray seems to work the best against cabbage worms when they first hatch so try and spray as soon as you notice any eggs or worms. 

Not only is BT spray one of the more organic options, but another benefit of using BT is also that over time the sun actually causes it to break down over time. It is one of the most natural sprays you can use that is also effective.

Researchers at the University of Maine also note that the time of day when you spray matters as well. This is to help protect the dwindling bee population so they suggest spraying in the late afternoon or early evening.

Tip #6: Use Companion Plants to Keep Cabbage Worms Away

If you are an avid gardener then you know how beneficial companion planting can be to help deter pests. Using plants that attract pests can help keep them away from the plants you want to protect. 

Want to know a plant cabbage worms truly detest? Celery.

These worms cannot stand the smell or sight of celery plants. Using this option as a companion plant will help protect your cabbage for sure. Another plant that is on a cabbageworm’s list of disliked plants is thyme. 

Adding thyme and celery to your garden as companion plants is a great option to keep cabbage worms away. 

Tip #7: Attract Birds to Get Rid of Cabbage Worms

Birds such as sparrows and finches love to eat cabbage worms as a favorite meal. Installing bird feeders that attract these specific types of birds is a technique that works well to get rid of excess cabbage worms. 

Finches and Sparrows like specific types of bird seed. Using this Wild Bird Seed in a bird feeder will help attract the birds that will help keep your cabbage worm population under control by adding the worms to their meal for the day. 

For more ways to attract birds, head on over to our article about why birds are attracted to some of your spaces! Here, you’ll find a bunch of things that attract birds, so that you can implement them into your own home and garden!

Tip #8: Spray Your Plants With Insecticidal Soap 

When growing plants for food consumption, it is imperative that any sprays you use for pests be safe for humans. Luckily there are options available that are safe but also do the job of getting rid of the unwanted pests eating your plants.

Insecticidal soaps are the original version of a pesticide. Used by gardeners for hundreds of years, they were originally designed simply from soap used around the house.

Gardners noticed they would dry out insects, getting them off of the plants but still leaving the plants able to be eaten once they were fully grown.

This type of spray works best on insects with softer bodies such as cabbage worms. This Garden Safe Insecticidal Soap is a popular choice among gardeners and even gets rid of other unwanted pests too.

Be Proactive in Preventing Future Cabbage Worm Infestations

It can be a lot of work to make sure that cabbage worms are out of your plants. After you use the methods mentioned and you have finally gotten rid of the cabbage worms in your garden, you want to be sure to find ways to prevent them from returning.

One of the most effective methods for keeping cabbage worms from coming back is using row covers.

These Garden Fabric Plant Covers will do the trick in helping to protect your plants from pests while adding the additional benefit of protecting plants from a hard freeze too.

Using row covers helps protect your plants to make sure cabbage worms are not able to infiltrate your new cabbage plants.

The Reproductive Timeline of Cabbage Worms Matters!

chrysalis of common cabbage worm on green leaves

The more information you learn about pests you are trying to control, the better equipped you will be to protect your garden.

Understanding the life cycle of a cabbageworm can be helpful in preventing future damage as well as knowing when to apply certain sprays and protection for your plants. 

Cabbage Worms Reproduce VERY Fast 

Just like any caterpillar, cabbage worms have a life cycle that starts with the eggs, moves on to the larvae stage (where you see the worms), and then to the pupae and adult stages.

The cycle can happen quickly so it is important to note what you are seeing and when. If you are seeing the white butterflies, that means that you will likely be seeing the worms themselves shortly after.

Researchers at the University of Wisconsin-Madison noted that the average timeline for the white butterflies to lay their eggs is in May and then eggs hatch quickly, usually within a week’s time.

Remember that when using sprays it is better to spray the cabbage worms themselves instead of the eggs as the spray is meant to be used for adult insects.

Each Year There Are Multiple Generations of Cabbage Worms Born

Once the eggs hatch, cabbage worms feed aggressively for 2-3 weeks before the next stage of their cycle.

Once the worms turn into a pupa, it typically takes 10 days for them to emerge as a butterfly. And then the cycle starts all over again.

Throughout one year time, there are usually 3-5 generations of cabbage worms, with the summer generation causing the most damage to plants and crops.

Because the cycle is such a short cycle, it is important for you to act swiftly once you spot the first signs of damage from the worms.

If you plan ahead for cabbage worm control by knowing when the stages of the life cycle occur, you will be able to protect your cabbage plants before the cabbage worms get ahold of them.If you are unsure how to protect your plants or get rid of the cabbage worms, make sure to contact your local professional.

Quick Recap

Building your knowledge of cabbage worms and ways to control them will help you maintain a clean and productive garden. Remember these tips and tricks below to keep these pests from taking over your plants: 

  • Be willing to get a little dirty by handpicking the eggs and worms off of your plants. Just remember to distinguish between cabbageworm eggs and ladybug eggs. 
  • Plant companion plants such as celery or thyme to keep cabbage worms isolated to specific areas of your garden. 
  • Take advantage of trap plants such as a mustard plant to lure cabbage worms to those plants and then dispose of the plants once they are full of cabbage worms. 
  • Use nontoxic BP spray to help protect your plants but keep humans and animals safe. A reminder to spray towards the end of the day so you are targeting the cabbage worms and not other insects such as bees. 
  • Attracting certain birds such as Finches and Sparrows will help get rid of cabbage worms on your plants. 
  • Insecticidal soap is a tried and true remedy for getting soft insects off of your edible plants. 

While it may take some time to weed the worms and eggs out of your plants, it is worth it to have lush and delicious cabbage plants to enjoy.›

References 

Chittenden, F. H. (1916). The common cabbage worm (No. 766). US Department of Agriculture.

Embaby, E. S. M., & Lotfy, D. E. S. (2015). Ecological studies on cabbage pests. International Journal of Agricultural Technology, 11(5), 1145-1160.

Jaques, R. P. (1972). Control of the cabbage looper and the imported cabbage worm by viruses and bacteria. Journal of Economic Entomology, 65(3), 757-760.

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