Cutworms

How to Identify and Get Rid of Cutworms

black-cutworm-control-prevention

Black cutworms can wreak havoc on your garden, so learn these tips for identification and control.

GrowVeg.com/Sam Droege on Flickr Creative Commons

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Cutworms can be a major annoyance in the garden, particularly for young seedlings or transplants. Here are tips on how to identify, control, and get rid of cutworms.

What are Cutworms?

“Cutworm” is the name used for the larvae of a number of species of adult moths. Eggs that hatch in the fall can produce larvae capable of overwintering in the soil or a woodpile. They do the most damage early in the gardening season, when they emerge from hibernation. Cutworms are caterpillars, but they are often mistaken for the grubs of beetles such as Japanese beetles (which are damaging in their own right).

Identification

How to Identify Cutworms

Cutworms are common on a wide variety of vegetables and any fresh seedlings. To identify them, try patrolling your garden in dusk and evening hours, when cutworms will begin to feed. They are also partial to cloudy days.

Different species range in color from grey to pink, green and black and can be as long as two inches. They can be solid, spotted, or striped. They tend be curled up when they are not on the move. Cutworms are stealthy, and tend to feed only at night, while hiding in daylight hours.

Black cutworms, also known as Agrotis ipsilon, are some of the most common cutworms. They have small dark spots on their bodies and mature into the dark sword-grass moth. Variegated cutworms, another common species, are mottled brown and have a faint white stripe down their backs.

Adult cutworms are moths of dark wing colors. They are usually brown or gray, and they are about 1 ½ inches long with a 1 ½-inch wing length. You should keep an eye out for them, because the females will lay eggs in dry soil after they mate.

brown-cutworm-moth-identification.jpg
Photo Credit: GrowVeg.com/gailhampshire on Flickr Creative Commons. The adult moth of the brown cutworm is an indicator that cutworm eggs could be in your soil.

Cutworm Damage

Cutworms chew through plant stems at the base. They primarily feed on roots and foliage of young plants, and will even cut off the plant from underneath the soil. In most cases, entire plants will be destroyed; they do a lot of damage in no time at all. Even if only the bottom of the plant is destroyed, the top will often shrivel and die.

In the summer, cutworms sometimes crawl to the tops of plants and do damage there. Be careful not to mistake this damage for slug damage.

prevent-cutworm-damage.jpg
Photo Credit: John Obermeyer, Purdue University. Black cutworms can cause severe injury to the base of plants, often killing them.

Control and Prevention

How to Get Rid of Cutworms

  • Make plant collars. Put a 4-inch piece of cardboard around each plant stem to help stop cutworms from reaching tender stems, especially right at transplanting. This time-consuming task works, though it is only efficient for a smaller garden.
    • Or, try this method: Save toilet paper tubes, cut them in half, fill with potting soil, and stand up in a tray. Use for planting seeds. When young plants are ready, plant them, tube and all. 
  • Hand pick. Go out at night with a flashlight and gloves. Pick off the cutworms and drop into soapy water; repeating this every few nights.
  • Sprinkle used coffee grounds or egg shells around your plants.
  • Circle stems with diatomaceous earth, a natural powder made from ground up fossils which kills insects when they walk over it.
  • Apply an insecticide late in the afternoon for best control. Some readers use Bacillus thuringiensis, a natural way to kill cutworms. However, note that this bacterium may harm butterflies, an important pollinator.
  • Try this folk advice from The 1963 Old Farmer’s Almanac
    • A mulch of oak leaves is useful against cutworms.
    • Tansy planted near cabbages keeps them free of cutworms.
    • A hog turned into a garden in early spring will root up cutworms.

How to Prevent Cutworms

  • In the spring, emerging cutworms will be waiting to feast on your garden. Cut off their food supply by delaying transplanting or planting by a couple weeks if possible.
  • Keep up with cultivation. The moths prefer to lay eggs in high grass and weeds. At the end of the season, plow or till the garden and mow surrounding areas to expose cutworms and destroy their winter habitat.
  • Fireflies are a fun insect to have around the garden, plus they are a natural predator to cutworms. Check out these tips to attract fireflies to your garden.
  • Birds are another natural predator to cutworms. Learn how to make your garden bird-friendly.

Plants Affected

Reader Comments

Leave a Comment

Lawn cutworm

How do I get rid of cutworm in my lawn? I also have tiny white butterflies laying around my lawn, I have used Ortho bug be gone spray and the seven crystal bug killer and none of them has worked. Can you help me? Thank you.

Killing Cutworm Alternatives

Multiple chemical applications negatively impacts the health of your soil, which is key to a healthy lawn. After a good rain, go out after dark with a flashlight and handpick as many of the cutworms as you can (drown them in soapy water). They don’t like dry soils, so water well in the mornings. Release beneficial nematodes, which will attack the cutworms (given your soil is likely not biologically rich, it may take some time and a few releases to start to establish a healthy population). The moths should be dealt with as soon as you see them: release tricogramma wasps weekly for three consecutive weeks–they will parasitize cutworm eggs. Apply Eco-bran on the lawn surface to attract (and kill) catapillars.

cutworms

I've read through your contents on cutworms, I believe that is what I have. We came home after being gone 4 days....early July so all my broccoli heads have produced, a few of my cauliflower, but still have the broccoli, remaining cauliflower and Brussel sprout plants growing. But these are full grown plants, no young seedlings. There were holes all through these leaves....and we plucked several dozen "green cutworms". But this was not at night...6 pm, plenty of daylight here in WY. I'll continue to look every day, but what can I do to protect my remaining plants? Fels Naptha soap solution?

how to control cutworms

Try the following: Sprinkle used coffee grounds or egg shells around your plants. Also you can circle plants with diatomaceous earth, a natural powder made from ground up fossils which kills insects when they walk/crawl over it.

'Cutworms' on cauliflower and broccoli

These aren't cutworms. I think what you had there were the caterpillars of the Cabbage White butterfly which are an extremely common pest of Brassicas. The eggs are laid by the adult butterflies on the underside of the leaves. When they hatch, the green caterpillars can quickly turn an entire plant into a skeleton.

The tops of our tomatoes

The tops of our tomatoes keep getting eaten off. It looks a lot like the work of a cutworm, but they are eaten off just below the foliage. The main stems are mostly affected, but the some of the side leaf stems were eaten off as well.I wrapped the whole stem up in tin foil right up to about an inch below the main foliage, but I went out the next day and one was eaten just above the foil. I have had cut worms before and they only ate near the bottom, but this is all the way up to under the main foliage where the blossoms start. The stem just gets bitten off, and the top is left lying there. What do you think is going on? I'd appreciate any tips to help!

cut worms

This is heartbreaking. It certainly sounds like cut worms. Are you smoothing the aluminum? You want to create a surface that has sharp edges, a surface on which the worms will cut themselves as they attempt to cross or climb it. So crinkle the aluminum around the stem. Or sprinkle crushed egg shells at the base of the plant. Even sharp pebbles. Some people cut the bottom out of paper/plastic cups and sink the cups around vulnerable seedlings. Half-gallon milk jugs from which the bottom and tops/necks are removed fit easily over larger plants. Others use (paperless) toilet rolls, but plants have to be small for those to fit.

We hope that helps!

Moringa tree and corn seed

My moringa tree has ten pods and no leaves. It is about six feet tall. Why won't leaves grow? Now my corn seeds need help.

Cutworms and our lawn

We live just south of Ocala and recently began to see our lawn start to die out. I found what looks to be a cutworm in the grass while raking the dead grass out of the yard. Could these worms be doing this kind of damage to our yard? If so, I will give these remedies a try.

Cutworms and army worms can

Cutworms and army worms can damage a lawn. If you identified the worm (or worms) as cutworms you can try some of these remedies. It’s important to keep your lawn healthy. A healthy lawn will withstand a cutworm attack.

Cut worms

Thanx for the idea for getting rid of cut worms

cutworm?

We live in Kommetjie, a little seaside village. I have lovely pots either side of the front door and planted white roses which have not been looking good (leaves dry out and brown) and thought I it was just because everyone says roses dont like sea air. Today I turned the soil in the pots and discovered thick fat worms everywhere which I think are cutworm!! How do I get rid of them? Should I just empty the pots and start again?

Cutworms

I have lots of CUTWORMS in my home. Please help me in solving these problem. They are spreading everywhere in my home. They are making nest on walls of my home. I am very in problematic situation.

Wormy situation

Hi, Taseer: Cutworms live in soil, so you will want to make sure that you minimize whatever dirt may be inside your house, including in plant pots. If indeed you don’t have cutworms but instead some other sort of caterpillar, then the trick is to find out how they are getting in (or got in, to lay their eggs). If you can figure out where their nests are, sometimes it’s possible to insert a shop vac (even if you have to create a temporary hole, but be careful about electric lines) and suck out the nests. Unfortunately, the best remedy is simply to remove them as they emerge, but the key thing to all of this is to seal your walls, including the bottoms. Good luck!

Something has eaten the bark

Something has eaten the bark of a tomato plant and left white film on the bottom of the stem. What is this and how can I treat it?

If it is cut worms you can

If it is cut worms you can try some of the tips above. Make collars out of paper or cardboard and put around the stems. You can also try to spray the plant with insecticidal soap spray (a few drops of dish soap mixed into a quart of water).

I have some young (less than

I have some young (less than a year old) citron plants and today I discovered that a pest has eaten the leaves from the outside in and it has eaten the outer stem of some of these plants while leaving the core stem intact. Please help me figure out what kind of bug this is and how to get rid of it!

Citron is attacked by many of

Citron is attacked by many of the common citrus pests. Could it be that two pests are attacking your plants? Such as grasshoppers or orangedog caterpillars on the leaves and rabbits or rodents girdling the trunk? Depending on where you live, pocket gophers, ground squirrels, voles, etc., may chew the bark and girdle the tree. See below for some common citrus pests and how to control them. Good luck!
http://www.ipm.ucdavis.edu/PMG...
http://edis.ifas.ufl.edu/ch056
http://edis.ifas.ufl.edu/cg005

The stems and leaves on the

The stems and leaves on the lower part of my tomato plants are dying. Is this the sign of cutworms? I have not seen any.

No, it sounds if you have

No, it sounds if you have "early blight" which is caused by a fungus. Avoid splashing any water on the leaves. Irrigate at the ground level and do not water from overhead. Remove any plant debris. Remove leaves in the lower 8 to 12 inches of the plant. Get rid of all the infected plants parts. If caught early, get a fungicide from your garden center to spray your plants, as directed.  See more about growing tomatoes on our "Tomato" page here: www.almanac.com/plant/tomatoes

I have cucumber and

I have cucumber and cantaloupe seedlings that have been outside for a couple of weeks (zone 5) and suddenly I am finding them cut off cleanly about 3" above the ground - a couple of plants each night. I didn't suspect cutworms because the plants are large (trailing a foot or more now), the cut lines are high and I thought that it was too late in the season. Didn't find any cutworms on a search tonight. Could it be cutworms after all - or something else? Thanks very much for any advice you can offer.

It could be that an animal is

It could be that an animal is munching on your seedlings, such as a rabbit, squirrel, deer, or groundhog. Rabbits tend to cut off vegetation cleanly, while deer damage might be more ragged. If you suspect an animal pest, you might try installing a motion-detector sprinkler.
For more information, see:
https://extension.umd.edu/grow...
http://theiowagardener.com/Wha...

I have a problem with my

I have a problem with my yellow squash plants. after the plant matures and start putting off squash, something eats the root of the plant causing it to die. I've checked for cut worms, voles and anything thing else I can think of. But it only eats my squash plants, not the tomatoes, the beans, broccoli, peppers.....nothing but the squash. Any help would be greatly appreciated.

Thank you.

It sounds like the dreaded

It sounds like the dreaded squash borer. They overwinter in the soil, especially if you grew squash in the same place before. If you make a vertical slit in the stem with a sharp knife, you'll see them and can manually remove the larvae. Afterwards, mound soil over the stem to encourage re-rooting. Then you just have to see if your squash will recover. Unfortunately, at this point, most insecticides are not effective.
You can get ahead of squash borers by planting disease-resistant types,  using row covers (which you remove when it's time for pollination), starting planting earlier, and rotating crops.

Prevent cutworms in your garden

We had lots of problems with cutworms in our garden, until we put our wood ashes on the garden on the snow during the winter while cleaning out our outdoor wood furnace once in a while, spring came, and the snow melted, the ashes soaked into the ground, later we tilled it in, NO MORE CUT WORMS, but you can also sprinkle it on in the spring before tilling

I planted broccoli,

I planted broccoli, cauliflower, brussel sprouts, and cabbage about two weeks ago. All were cut down. I put out diatomaceous earth and corn meal and then replanted some broccoli yesterday with pencils stuck down beside them, plastic cups around them and diatomaceous earth around them. I went out after dark to check for worms and found none but went out today and almost all my plants were cut off. What can I do to stop them? This is a new garden spot that was in grass which I know makes them worse but there has to be a way to stop them! HELP!

Hi Cecilia, The collars or

Hi Cecilia,
The collars or cups that you put around the stems need to be pushed down a couple of inches into the soil so that the cutworms can't get under the collar. You can also try to wash the plants with a mix of bleach free dish soap and water. Also see the answer to the question from Karen below.

October last year we finished

October last year we finished our drive laying new turf slabs at our front door and placing a new rubber backed mat down. Over the last few months when we have lifted our mat up there have been lots of black caterpillar/maggot like grubs underneath it. A large area of our lawn (next to the mat died. Yesterday we dug up that area ready to re-turf it and found lots of these grubs. Can you please offer me your thoughts on this and how you think I may eradicate the problem.

Hi Karen, You probably have

Hi Karen,
You probably have black cutworms. Read our tips above about how to get rid of them. There are a couple of biological control methods that you can try, parasitic nematodes and Bacillus thurbingiensis (Bt). You can read more about this at
http://entomology.osu.edu/bugd...
 
 

If you want to control a

If you want to control a large area use Sevin granules. If you want to treat individual plants use Sevin 5% dust. Lightly dust around the base of each plant. Individually treating plants is preferred with dust so you dont kill everything in your yard...including your beneficial insects. Just a little dust at the base of each plant will work wonders. Read the label.

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