How To Get Rid Of Cutworms (10 Natural Ways To Do It)


If you have ever gone into your garden in the morning and seen some of your plants cut off at the base, then you know how annoying cutworms are.  Luckily, there are plenty of ways to keep cutworms at bay and protect the plants in your garden.

So, how do you get rid of cutworms on plants?  To get rid of cutworms on plants, pick them off by hand at night when they feed, or spray them with soapy water. Use a “cutworm collar” to protect plants: put a cardboard tube around the base of each stem. You can also put diatomaceous earth on the soil around each plant to form a barrier.

Of course, you can also keep your garden clean and attract birds to help with cutworm control.

In this article, we’ll talk about 10 natural ways to get rid of cutworms in your garden.  We’ll also talk about what cutworms are and how to recognize them.

Let’s begin.

What Are Cutworms?

Despite their name, cutworms are not actually worms.  They are caterpillars, and they are small – usually less than two inches long.

cutworm
A cutworm curled up into a “C” shape.

Cutworms will curl up into a “C” shape when resting or after being disturbed.  They are sometimes mistaken for grubs.

Cutworms are the larvae (immature form) of certain moths, which have several life stages.  First, a moth lays eggs in or near your garden.

cutworm eggs
Moth eggs, which will hatch into cutworms in spring.

Next, in the fall, the eggs hatch into larvae (cutworms). These larvae will wait out the winter in soil or underneath organic matter (leaves, wood, etc.).

Then, in the spring, the larvae (cutworms) come out of hibernation to feed on plants, such as the ones in your garden.  Finally, the larvae become pupae, which eventually become moths to repeat the whole cycle.

cutworm pupae
A moth pupae – not the final form of the moth though!

Cutworms like to come out to feed in the dusk or evening hours and on cloudy days.  They prefer to stay out of the daytime sun.

This makes them less of a target for predators like birds. However, we can use this preference for staying out of sunlight to our advantage (more on this later).

How Do I Know If I Have Cutworms In My Garden?

There are several ways to tell if you have cutworms in your garden. Look for some of these signs.

Plants Are Cut Off At The Stem

Seeing “decapitated” plants is the most obvious and annoying sign of cutworms in your garden.  Usually, this happens to younger plants, such as ones you have just bought at the store or transplanted from your home or greenhouse.

It will look like someone took a pair of scissors and cut off your young plants at the base.  However, what really happened is that a cutworm was crawling along and found your plant.

cutworm damaged plant
Image courtesy of user:
Frank Peairs,
Colorado State University,
United States via:
Wikimedia Commons: https://commons.
wikimedia.org/wiki/File:
Agrotis_ipsilon_larva.jpg

Then, it wrapped itself around the plant’s stem at the base.  Finally, it chewed at the stem until it cut all the way through, severing the top and most likely killing your plant.

If you are really unlucky, a cutworm will go down a row of plants, cutting off each one as it goes.  The only limit to the damage is how far the cutworm can travel in one night!

Remember that in some cases, cutworms will also climb up a plant and feed on the fruit, buds, or leaves.  There is even one variety (the glassy cutworm) that feeds on the roots of plants.

You See Cutworms Or Moths In Your Garden

You may also catch cutworms in the act of climbing up or chewing on your plants.  As mentioned before, you are most likely to see them in the dusk or evening hours.

Cutworms come in many colors. Black is a common color for cutworms.

However, you may also see them in green, gray, or even pink. Cutworms can be solid, but they can also have stripes or spots on their bodies.

Moths are the adult form of cutworms. If you see them in your garden, there is a good chance that you have cutworms, or that you will in the near future.

cutworm moth
If you see moths in your garden, they may be laying eggs, which can lead to cutworms later on.

Luckily, there are some steps you can take to interrupt the life cycle of cutworms (more on this later).

You See Birds In Your Garden

Birds like to feed on cutworms. If you see more birds than usual in your garden, then it could be a sign that there is an infestation of cutworms (or some other pest that birds like to feed on).

cardinal
Cardinals like to feed on cutworms and other crawling creatures.

If you can make the birds feel welcome, they might help you with your problem (more on this later).

How To Get Rid Of Cutworms

There are plenty of ways to get rid of cutworms on the plants in your garden and keep them from coming back.

Creating barriers to protect your plants is one possibility.  You can also use natural or chemical insecticides.

Planning ahead to interrupt the life cycle of the cutworms is another way to keep them under control.

Let’s get into the steps you can take to protect your harvest from cutworms. Many of these methods are natural and do not require the use of any artificial chemicals.

Cutworm Collars (Plant Collars)

Cutworm collars are a protective barrier for your plants. The idea is that they wrap around the stem of a plant to keep cutworms away.

A classic way to make a cutworm collar is to use cardboard. Cut the piece of cardboard into square strips (perhaps 4 inches long by 4 inches wide).

Then, take the cardboard strip and wrap it around the stem of the plant to form a cardboard “tube”.  Push the tube down about halfway into the soil to keep it in place.

cardboard boxes
Cut cardboard boxes into squares of cardboard and shape the pieces into tubes to make plant collars.

Note that partially burying the cardboard tube will also prevent the cutworm from going under the tube.

It is possible that a cutworm could climb over or under the tube.  However, it is more likely that it will keep crawling along flat ground to find easier prey (such as the weeds in your garden, which are conveniently unprotected!)

You can make cutworm collars out of anything that will keep cutworms at bay.

Cardboard is a good choice, because it biodegrades over time. However, you will have to make more of them every year, since cardboard breaks down so fast.

Plastic bottles will also work as cutworm collars, and they are reusable. However,you will need to cut the bottom out of them, and they will take a long time to biodegrade.

water bottles
You can use plastic bottles with the top and bottom cut out to make reusable plant collars.

Another related trick takes a little more planning.

First, save up cardboard tubes from empty rolls of toilet paper and paper towels.  You can also ask friends and family to save them for you.

Then, cut them to the appropriate height, place them in a tray, and put some soil in the tubes to plant your seeds.  Once the seeds germinate and the seedlings are large enough, you can transplant the whole thing into your garden – plant, cutworm collar and all!

cardboard rolls
You can use paper towel or toilet paper rolls as cutworm collars. You can also form collars out of a square piece of cardboard.

Diatomaceous Earth

This is another method that creates a protective barrier around your plants while also acting like a natural pesticide.  You can use this method together with cutworm collars, but it might be overkill.

First, buy some diatomaceous earth, which is a white powder made from rock.  Then, sprinkle the diatomaceous earth to form a ring on top of the soil around your plant.

diatomaceous earth
Diatomaceous earth – deadly to bugs everywhere!

Whenever insects (including cutworms) crawl over the diatomaceous earth, it will kill them.  Basically, the fine white powder is “sharp” enough to cut bugs, which then lose water through the cuts and dry up.

Diatomaceous earth is also good for killing ants – for more information, check out my article on getting rid of ants.

You can find diatomaceous earth from Gardener’s Supply Company.

However, diatomaceous earth is fine for humans to handle, making it a safe pesticide. It is still wise to wear a mask when using it, though.

There are some drawbacks to this method.

First of all, it is an indiscriminate killer. In addition to cutworms and ants, diatomaceous earth will also kill ladybugs, bees, and other beneficial insects in your garden.

ladybug
Diatomaceous earth may kill ladybugs and bees in addition to cutworms and ants.

Another problem with this method is that rain or watering may wash away the diatomaceous earth. That means you might have to reapply it after every watering or rainfall.

Leave A Bare Soil Border Around Your Garden

A bare soil border is another way to create a barrier for your garden.  Instead of protecting plants one at a time, you create a barrier around your entire garden all at once.

The idea is to leave a bare patch of soil around the outside of your garden.  Ideally, there will be no shade on this soil, so the soil will be extremely dry and exposed to daytime sun.

sandy soil
A bare soil border around your garden creates a dangerous wasteland for cutworms – one that they may hesitate to cross.

Any cutworms that want to feed on your plants will have to cross this barren wasteland. They will risk dying in the sun or being eaten by birds that can see them clearly.

They are also less likely to lay their eggs on this bare ground. According to the University of New Hampshire Extension, most cutworms lay eggs on the stems of plants (such as grass or weeds).

If you want to level-up your garden defenses, pair this method with diatomaceous earth.  Simply sprinkle a line of diatomaceous earth along the top of the bare soil border on the outside of your garden.

There is one thing to keep in mind, though.  This method will only keep new cutworms from crawling into your garden.

The cutworms that are already in your garden will not be able to leave.  Furthermore, moths will still be able to fly into your garden and lay their eggs.

Although it is not a perfect defense, a bare soil border is certainly helpful.

Make Birds Feel Welcome In Your Garden

This is a nice, simple method that won’t take much time. Even better, it can be paired with some of the other methods mentioned earlier.

Birds are a predator of cutworms, so they act as a natural pesticide. If you rely on them for help with cutworms, you won’t have to worry about artificial chemicals on your plants.

Put out a bird feeder and a bird bath to make the birds feel welcome.  They might show up for the free sunflower seeds, but they will stay for the cutworms and other garden pests.

bird bath
These birds feel welcome, and will probably keep cutworms at bay!

You could even put a bird bath at each corner of your garden, which has a nice decorative effect.  If the birds see any invading cutworms, they will swoop down and do your dirty work for you.

Add Some Beneficial Nematodes

Beneficial nematodes are tiny creatures that look like worms.  They are parasites that are effective against cutworms.

nematode
Nematodes are tiny creatures that look like worms. Some of them are parasites to cutworms and other pests.

According to the University of Vermont Extension, beneficial nematodes are also parasites of armyworms, and caterpillars. There are various types of beneficial nematodes that you can use to help fight cutworms.

Buy some beneficial nematodes and release them in your garden to help control cutworms without chemical pesticides. You can find beneficial nematodes from Planet Natural.

Clean Up Your Garden

You were probably going to do this anyway. However, if you do it well enough, you can prevent much of the carnage that cutworms will cause.

After the fall harvest, take any plant debris and remove it from the garden.  Either burn it, or put it in a compost pile far away from the garden.

compost bin
Clean up any plant debris and leaves from your garden in the fall to prevent cutworms from having a safe place to spend the winter.

Just remember: if there are already eggs or larvae in your garden, a compost pile gives them a good place to wait out the winter.

If you want to compost the plant waste, a better idea is to have two different compost piles.  Then, you can alternate the years that you use each pile.

compost
Composting some leaves and food scraps for the garden.

The cutworms that over-winter in the unused compost pile will need to leave in the spring to find food.  That means you aren’t putting so many cutworms back into your garden.

Till Up Your Garden Soil

Even though you cleaned up your garden in the fall, make sure to do it again in the spring.  Then, till up the soil, either by digging or using a rototiller.

front tine tiller
Till up the soil to give birds a shot at any cutworms or larvae you expose.

If you don’t have a machine or don’t want to do it yourself, check out my article on the price of rototilling.

Leave the soil unplanted for a while, and give the birds a shot at any cutworms that you may have unearthed.

Plant Later In The Spring

If you can, wait a little longer to plant in the spring.  If you start your own plants from seeds, keep them indoors or in the greenhouse a little longer.

radish seedlings
If you can, wait a little longer to transplant seedlings outside in spring. Cutworms may move on to other places to feed.

That way, the cutworms may starve before they get a chance to feed on your plants.  At the very least, some of them will give up on your garden and move on to greener pastures.

Add Sacrificial Plants

You can also add sacrificial plants on the borders of your garden that the cutworms can eat.  Maybe you could plant some extra seedlings that you raised (or plants that you don’t really care about) to keep the cutworms busy.

Declare War On Cutworms

This method is barbaric, and not very efficient.  Here is how it works: you go out into your garden at night with a flashlight and find cutworms.

cutworm
You can always get rid of cutworms the old-fashioned way: by picking them off and crushing them.

Then, you pick them up off the ground or remove them from your plants.  Finally, you … put them between a rock and a hard place (usually another rock).

It might not seem like a few cutworms matter, but each one of them could lay many eggs in a season.

Buy Chemical Solutions Off The Shelf

There are countless chemical pesticides that you can buy online or at a garden center.  However, these will end up in your soil, in your plants or on your food.  I would do this only as a last resort.

Conclusion

Now you know what cutworms are, what they look like, and how to recognize the signs that they are in your garden.  You also know aboutlots of natural methods to prevent cutworms from hurting your plants.

You can learn more about other types of worms that eat tomato plants in my article here.

I hope you found this article helpful – if so, please share it with someone who can use the information.

If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here.  Enjoy!

~Jonathon

jonathon.david.madore

Hi, I'm Jon. Let's solve your gardening problems, spend more time growing, and get the best harvest every year!

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