If you notice fat, grayish brown, greasy-looking worms on your tomatoes or other plants, those might be cutworms. Plants may also appear to have been chopped off at the base and ruined.
This is the night-time damage of cut worms, larvae (caterpillars) of dark-winged moths, feeding on your plants. As a result, you need to eliminate them before any further damage is done and new plants are put in.
Here’s how to get rid of cutworms naturally.
1. Manual Removal
Cutworms are nocturnal feeders so a flashlight is needed to find them on the roots and foliage of plants.
They come in many colors and patterns so may also be difficult to identify. However, most usually appear as small brown, gray, or even black stout caterpillars.
Pick them off and squish or feed them to the birds. Alternatively, drop the cutworms in a bucket of soapy water to suffocate and kill them.
2. Coffee Grounds
An inexpensive home remedy to repel cutter worms is to use leftover coffee grounds to sprinkle around your plants.
Coffee grounds will not kill cutworms; however, the critters don’t like the stuff.
3. Beneficial Nematodes
Another cutworm management tip is to utilize beneficial nematodes. These microscopic organisms live in soils and act as parasites on harmful insects, helping to control the pests.
You can purchase these from online suppliers or local garden centers and reintroduce them into garden soils to keep cutworms away.
Crushed eggshells are useful in the garden in a number of ways.
It will stop cutworms as the sharp edges will damage their soft bodies and kill them. The eggshells will then biodegrade, leaving a beneficial residue of calcium.
5. Cutworm Collars
Cut pieces of cardboard and shape ‘collars’ around each plant to prevent the larvae from chomping around the base or devouring the whole plant. Push the collars down well into the soil to form a secure barrier.
Moreover, plastic cups are more durable and useful if the ends are cut off to form tubes. However, it is a more time-consuming and non-biodegradable option.
6. Pest-Repelling Plants
These critters feed on roots, stems, leaves, buds, and even fruits; however, there are some plants and scents that they do not like. Plants that repel cutworms include tansy, sage, and thyme. Moreover, borage keeps away tomato worms.
7. Till the Soil
This is a simple method to control cutworms organically.
Breaking up the soil and digging deep before spring planting will expose and/or destroy overwintering larvae or pupae.
Also, digging around existing plants will evict some pests from their hiding places. Collect and dispose of them.
Another good idea is to leave the area for a while to let the birds do the work for you.
8. Bamboo Skewers
Poke these directly into the ground around plants to keep cutworms off your plants. It will prevent the plant worms from curling around the stems, chewing, and ruining them.
Form the skewers in a circle around the plants in a sort of a stockade against pest attacks.
9. Clean Up
A good clean-up of the garden at the end of the summer should clear away a lot of debris where cutworm moths have laid eggs. Dispose of the debris well away from the planting area to avoid a new infestation in the spring.
At this point, till the soil again to expose any larvae left behind.
Another easy DIY remedy to get rid of cutworms in the vegetable garden is using toothpicks.
You can use these like bamboo skewers around plants to corral them against the larvae chewing the bases and stalks.
You can use cornmeal as a natural remedy to deal with plant-eating worms.
The staple is indigestible, so generally a little of this product sprinkled near plants is effective for treating the problem. Cornmeal will kill the cutworms that overeat it.
12. Diatomaceous Earth (DE)
This is a slow but effective organic treatment for black and army cutworms in your yard, among other pests. DE is a white powdery substance that is made from the fossilized remains of tiny marine organisms.
Its sharp edges are abrasive and will cut into the soft bodies of cutworm caterpillars, causing dehydration that leads to death.
Therefore, sprinkle DE around plants, in the grass, and on the lawn. Additionally, food-grade diatomaceous earth is excellent for getting rid of house insects.
13. Natural Predators
Nature may bring unwanted insects but is also always ready to give the gardener a helping hand in eliminating them. Birds are particularly helpful in feeding on bad bugs, grubs, and garden worms.
Parasitic wasps are also useful. These parasitize the cutter worm and lay eggs inside it. As the eggs break and develop themselves into the larval stage, they will eat the host.
Some beetles, spiders, frogs, and toads also eat cutworms. Additionally, bats are helpful in eliminating night-flying adult moths, thus preventing more eggs from being laid.
14. Bacillus Thuringiensis (B.t.)
This is a naturally occurring bacterium found in soils that produce proteins toxic and fatal to cutworms and other pests. However, Bt is not toxic to beneficial insects, wildlife, or pets.
Bacillus Thuringiensis is available online or from garden stores. Use it according to the specific instructions that come with the package.
15. Essentria IC-3
Essential oils have long been known as a deterrent in insect pest control. Essentria IC-3, a commercial product, goes further and contains a blend of oils in spray form to hit pest targets directly.
The knock-down reaction is quick and death follows rapidly. Although this product is effective against pests, it is safe to use where there are children, pets, or livestock nearby.
Diluted and sprayed, you can use it indoors and outside on a wide variety of insect pests including cut worms and adult moths.
This spray for cutworms is a unique blend of rosemary oil, peppermint oil, and geraniol.
16. Epsom Salt
Epsom salt is great for killing soft-bodied pests in your garden. Its abrasive texture will scratch their soft bodies which cause dehydration, leading to death.
To use Epsom salt for cutworms, sprinkle some around the base of your plants. This will prevent them from crossing over.
A natural pesticide, Spinosad is effective against many different types of harmful garden insects. This treatment is available in ready-to-use spray forms.
Spinosad insecticide kills cutworms. It acts by paralyzing the larvae, preventing feeding, and breaking the life cycle of the pests. However, it has the disadvantage of being toxic to honeybees, one of nature’s essential pollinators.
If however, it is sprayed in the evening and allowed to dry at times when bees are inactive, the product can be applied safely and effectively.
It is so disheartening for a gardener to find plants ruined but identifying the cause is the first step in eliminating the problem.
Checking at night for a cutworm infestation and applying one or more of these natural methods above should avoid any future attacks on plants.