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.
2. Coffee Grounds
An inexpensive and simple way to repel cutter worms is to use leftover coffee grounds sprinkled around the plants.
These and other pests don’t like the stuff.
3. 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 and local garden centers and reintroduce them into garden soils.
Crushed eggshells are useful as they are often available waste in homes.
The sharp edges can damage the soft-bodied larvae 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. Till the Soil
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.
7. Bamboo Skewers
Poke these directly into the ground around plants to prevent the plants 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.
8. 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 is using toothpicks. You can use these like bamboo skewers around plants to corral them against the cutworm larvae chewing the bases and stalks.
Cornmeal is often used as a natural remedy to destroy a colony of ants but you can also use it to deal with plant eating worms.
The staple is indigestible and will kill cutworms, so generally a little of this product sprinkled near plants will deter them.
11. Diatomaceous Earth (DE)
This is a slow but effective way to control cutworms and many other pests organically. DE is a white powdery substance that comes from tiny fossilized marine creatures.
This composition is sharp and can cut through into the soft bodies of larvae causing dehydration and eventually killing them. You can sprinkle DE around plants and on lawns, forcing the cutworm caterpillars to cross the barrier to reach the food source.
It is, however, most useful in eliminating pests on developed plants. Tender seedlings may still need barriers like ‘collars’ or a stockade of bamboo sticks.
12. 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 unwanted grubs and bugs.
Additionally, planting colorful scented flowers and/or providing a feeding box can attract these natural enemies to the garden.
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.
13. Bacillus Thuringiensis (Bt)
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.
14. Essentria IC-3
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.
The product is a unique blend of rosemary oil, peppermint oil, and geraniol.
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 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.