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.

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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.

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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

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Reader Comments

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We identified cutworms last

We identified cutworms last spring in our garden. Our corn and bean seeds were not germinating evenly and we dug to find cutworms larva eating the seeds themselves. We also had several seedlings cut off at ground level. Our garden is now "bare" with no foliage and we would like to pretreat the soil to make sure the larva are dead. We live in Zone 6 so the ground is just beginning to thaw. Would you recommend tilling the soil and them spraying an insecticide? Please help! Thanks!

Hi Lynsee, We don't recommend

Hi Lynsee,
We don't recommend insecticides for cutworm control. Instead use parasitic nematodes or certified organic BTK (Bacillus thuringiensis, var. kurstaki). You can make a bait with BTK by mixing it with rolled oats and molasses. Sprinkle it over the planting area before planting in the spring. The cutworms will feed on the bait and hopefully die before your seeds and plants go in.
 

Get some beneficial

Get some beneficial nematodes! They will eat the larvae.

Hello I live on a new site

Hello I live on a new site have lived in my house for just over 2 years I have a tiny garden and it was raining the other night and I noticed hundreds of small around 1 inch long worms all over my patio. My gras has completely does it's just mud with thousands of tiny looks like worm holes. How do I kill this off as I want to lay new turf. Many thanks Kieran Hanlon

Hi Kieran, It's hard for us

Hi Kieran,
It's hard for us to know what type of worms you have. You may have regular earthworms that come up to the surface of the soil when it rains. Earthworms are good for the soil. They aerate and enrich the soil, digest and break down organic matter, and improve soil texture. We suggest that you check with your neighbors to see if they have the same problem and maybe bring a couple of the worms to a local garden center for advice.

I have something that is

I have something that is eating the leaf of all of my leafy green veggies. I am not sure it is a cut worm. They are white or even clear w/redish legs, lots of them.
Can you tell me what they are and what to use for an organic garden?
I have also seen the red colored short worm/bug under the squash, please tell me how to get rid of them this year?
Thank you for your help!

I've caught some cutworms and

I've caught some cutworms and other caterpillars using a sticky tape or paper for catching flying insects - by laying it on the ground around the plants. Sometimes they crawl under it and I find them in the morning, and other times they get stuck to the paper.

Hi, I think I have cutworms

Hi, I think I have cutworms in my veggie patch but can't find any evidence of them whatsoever. Whatever is there is pulling down leaves into a small hole, sometimes half the leaf is under the soil with stalk up in the air. Does this sound like cutworms or could it be something else and if not, any ideas as to what?! Thanks.

It does not sound like

The Editors's picture

It does not sound like cutworms. You may have leafcutting bees but we are not positive. Are the leaves whole or have they been chewed on? What type of plants are effected?
You can spray your plants with a liquid soap water mixture to see if it will help.

Yes, careful digging in that

Yes, careful digging in that area will probably lead you to the culprit .

do cutworms attack grass and

do cutworms attack grass and when digging up the worms can they be all white and do skunks
dig and eat them leaving holes all over your lawn

You have lawn grubs,

The Editors's picture

You have lawn grubs, sometimes called white grubs. These are larvae of different kinds of beetles. The most common one is the Japaneese beetle. Please see our Japaneese beetles page for ways to get rid of the grubs. http://www.almanac.com/content...
 

it is september and the

it is september and the ground is full of white worms with reddish brown cutting teeth they chewed off grass roots made large gouges in my potatoes and are making a real mess are these cutworms and what kind of insecticide can i use to cover a large area

please add more clear images

please add more clear images of worms ....cutworms, how could we recoznize any worm ???

Hi Dinesh, We've added images

The Editors's picture

Hi Dinesh, We've added images of the more common cutworms and hope this helps. Cutworms come in many colors; some have stripes and some have spots. You only see cutworms at night so they main way you'll know you have cutworm infestation is if your plants are literally cut off near the base of their stems. You may also see droppings nearby.

what can i use tokill cut

what can i use tokill cut worms

The best way to keep cutworms

The best way to keep cutworms off your plants is to use a collar as they mention above. You could also use Bacillus thuringiensis which is available in most garden centers. You can kill the adult moths with bug zappers.

control for cutworms- you can

control for cutworms- you can use polytrin ,which is sprayed evening times

I have something eating the

I have something eating the tops of my tomato plants and now they are eating the tops of my cucumber plants. It is ruining my cucumbers. They have started blooming a little. I can't find any worms on them and this is the first time it has happen to me and it isn't happening to my neighbors who also have a garden. What could it be?

Some species of cutworms do

Some species of cutworms do climb plants to chew holes and edges of leaves. Cutworms usually feed at night--check the soil about 1/2 inch down around the base of the plants to see if there are any cutworms there. (Be sure not to disturb the roots of the vegetable plants.) As another possibility, could it be an animal, such as a rabbit? Slugs and snails may also eat leaves, feeding at night; check for evidence of slime trails, and go out to the garden at night with a flashlight to try to spot the culprit.

I have a larvae worm, similar

I have a larvae worm, similar to a cutworm boring holes in the soil in my vegetable garden. They appear to be brown striped with a horn like head. What kind of worm are these?

Cutworms often get confused

Cutworms often get confused with Squash Stem Borers. From what you described, I'm pretty sure you have the Stem Borer. Stem borers not only attack squash, but can attack pumpkins as well.

what is the time of year they

what is the time of year they start showing up in your garden and about when do they stop feeding in your garden ? (for southern Indiana)

In general, cutworms show up

In general, cutworms show up in spring when the weather warms. The larvae eat for several weeks before going into the soil to pupate. The moths will emerge to lay eggs that hatch in a few days. There may be several generations per year.  Cutworms may overwinter as eggs, larvae, or pupae, depending on the species. For best advice about timing in your area, we'd recommend talking to a local garden center or your county's Cooperative Extension:
http://www.almanac.com/content...
You might be interested in this article from Purdue University about the black cutworm. It is for farmers that raise corn, but it has a chart about emergence times of larvae and adults of the black cutworm in Indiana:
http://extension.entm.purdue.e...

Will they climb up tall

Will they climb up tall planters? I just found a cutworm in a seedling I planted into a very large container with a bunch of other herbs (removed the cutworm, of course). I haven't found any others and I'm wondering if they'll be able to get up into the new seedlings. The pot is a good two feet tall.

Some cutworm species do

Some cutworm species do climb. Check the soil about a 1/2 inch down periodically to make sure other cutworms do not set up shop.

Cutworms: You say, "apply

Cutworms: You say, "apply insecticide". Plz name one or more commercial insecticides that I can purchase. Thank you.

You'll need to contact your

The Editors's picture

You'll need to contact your local garden center as insecticide usage and laws vary by state or province.

A neighbor of mine is having

A neighbor of mine is having trouble with cutworms coming into their house. She said they're even in her cabinets. What can she do? It isn't safe to put insecticide inside her place or her cabinets.

We've never experienced

The Editors's picture

We've never experienced cutworms in the home (only in the garden). We wonder if it's a different kind of worm?  See this page for reference: http://www.ext.colostate.edu/p...

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