Cutworms are caterpillars of several moth species in the family Noctuidae. Many spend the day hiding in the soil or beneath plant debris before emerging to feed, often at night. Some species cut through young plant stems close to ground level, leaving seedlings wilted, collapsed or lying on the soil.
For gardeners, this damage can be especially frustrating. A seedling may look healthy one afternoon and be severed by the following morning. Swiss chard, spinach, lettuce, tomatoes and other young crops can be vulnerable, although the plants attacked depend on the cutworm species and the available food.
Learning to recognise the caterpillar, inspect the soil around damaged plants and use practical prevention methods can help protect new seedlings without relying immediately on chemical pesticides.
Written by Kutlwano Mokoena
Founder of Evergreen Hideout Agricultural Services (NPO: 2024 / 380375 / 07). Focused on insect identification, soil ecology and ecological gardening.
Quick Diagnostic Summary
Young seedlings may be cut through near soil level, causing them to collapse or lie flat while their roots remain in the ground.
Many cutworm larvae curl into a C-shape when disturbed. Check the soil and plant debris around damaged seedlings.
Search around the base of affected plants, remove caterpillars you find and protect replacement seedlings with suitable physical barriers.
Identification note: The name "cutworm" describes the larvae of several moth species. A curled caterpillar and a damaged seedling can suggest cutworm activity, but identifying the exact species usually requires more detailed examination.
🐛 First Encounter: The Fallen Seedling
My first memorable encounter with a cutworm happened during a garden expansion project at Raikana Primary School in Soshanguve, Pretoria. I was working alongside my friend and colleague, Emnes Baloyi. We were developing the garden through two initiatives: my project, Evergreen Hideout, and his, Alkemetic Vegetation Garden.
We had decided to expand the growing area, plant more vegetables and sell some of the harvest, building on the experience we had gained through Alkemetic Vegetation Farm. Swiss chard and spinach were among the crops we wanted to grow.
We planted new seedlings and incorporated chicken compost into the growing area, following our usual garden preparation routine. We often arrived early in the morning to check on the plants. On this particular morning, Emnes was inspecting one section while I checked another.
That was when I noticed something unusual: one of our seedlings was lying flat on the ground.
What I observed: The seedling had been severed close to ground level. My first thought was armyworms. I had heard about them as crop pests, but I knew I needed to investigate before deciding what had caused the damage. I gently searched the soil around the affected plant, just below the surface. There it was: a plump, smooth-looking caterpillar curled into a C-shape.
Its appearance and hiding place made me think of a cutworm. I had finally found the kind of caterpillar I had heard gardeners talk about. The damage also made sense: the seedling had been standing upright the previous day, and now its stem was cut through.
Many cutworm species feed after dark and hide in the soil or beneath debris during daylight. That behaviour offered a likely explanation for why we discovered the damage in the morning. However, finding a damaged plant the next day does not tell us the exact hour the caterpillar fed.
🐛 Personal Connection: This was my first real encounter with a cutworm. I had heard of them, but I had never found one in our garden. It was frustrating because we had put time and effort into raising those seedlings. At the same time, it was a valuable lesson. The garden was teaching us to look beyond the visible damage and investigate what was happening beneath the soil.
I shared what I had found with Emnes. We knew this was not the end of the project. We could replant the damaged area, inspect the remaining seedlings and improve our protection methods. That is part of gardening: learning from setbacks and adapting as we go.
The encounter taught me three important lessons:
- Look beyond the visible damage: A fallen seedling may have a hidden cause. Inspecting the soil around the stem can reveal a pest that would otherwise remain unnoticed.
- Learn to distinguish similar pests: Armyworms and cutworms are both caterpillars of moths in the family Noctuidae, but they can have different feeding habits. Their names alone are not enough to identify the culprit.
- Respond through observation: Checking seedlings regularly, investigating damaged stems and protecting new plants can reduce the chance of repeated losses.
📍 Location: Raikana Primary School, Soshanguve, Pretoria
📅 Date: July 2026
🌱 Crops: Swiss chard and spinach seedlings
🌿 Growing context: Garden expansion with Emnes Baloyi, using chicken compost during bed preparation
🔎 Observation: A seedling lying on the soil with its stem severed near ground level; a curled caterpillar was found just below the soil surface
How to Identify a Cutworm
Cutworms are the larval stage of certain moths belonging to the family Noctuidae. They are not one single species. Several noctuid moth species have caterpillars commonly called cutworms because of their habit of feeding on young plants and, in some cases, cutting through stems near ground level.
Although their appearance varies between species and growth stages, many cutworm larvae share several recognisable features.
Common Identification Features
- Body shape: Usually plump, soft-bodied and cylindrical, with a clearly segmented appearance.
- Colour: Depending on the species, larvae may be grey, brown, greenish, dark brown or nearly black. Some have subtle stripes or markings.
- Surface: Many have a smooth or slightly glossy appearance, although texture and markings vary.
- Defensive posture: A number of cutworm larvae curl into a C-shape when disturbed. This is a useful clue, but it is not unique to cutworms.
- Hiding place: Many rest in loose soil, beneath plant debris, around the base of plants or in soil cracks during the day.
- Size: Their size changes as they grow. Mature larvae can be several centimetres long, but there is no single size that applies to every cutworm species.
Cutworms and Armyworms: Are They the Same?
Cutworms and armyworms are both common names used for caterpillars of moths in the Noctuidae family. They are not interchangeable names for exactly the same pest.
Many cutworms hide in or near the soil and may cut young seedlings at the base. Armyworms are often associated with feeding on leaves and moving across crops in groups, although their behaviour varies by species. Some armyworm species have broad host ranges and can feed on many different crops.
For that reason, it would be inaccurate to assume that armyworms only attack cabbage and kale or that they cannot damage Swiss chard. The best approach is to examine the caterpillar, the feeding pattern and the affected plant before making an identification.
Important: A caterpillar found near a damaged seedling may be responsible, but confirming the pest is easier when the caterpillar is observed feeding or when its appearance and damage pattern match a known species.
Cutworm Life Cycle and Nocturnal Behaviour
Like other moths and butterflies, cutworm moths undergo complete metamorphosis. Their development has four main stages: egg, larva, pupa and adult moth.
- Egg: Female moths lay eggs on suitable surfaces, which may include leaves, stems, plant debris or other sites depending on the species.
- Larva: The egg hatches into a caterpillar. This is the stage responsible for feeding damage. The larva grows through several developmental stages, shedding its skin as it gets larger.
- Pupa: When ready to transform, the mature larva usually pupates in the soil or another protected location, depending on the species.
- Adult moth: An adult moth emerges from the pupa, mates and lays eggs, continuing the life cycle.
Why Are Cutworms Often Found at Night?
Many cutworm larvae are more active after dark. They may move out from their hiding places to feed on stems, leaves or other plant parts. During the day, they can retreat into the soil, hide beneath debris or remain close to the base of their host plants.
This behaviour explains why gardeners sometimes discover damage in the morning without having seen anything feeding the previous afternoon. However, not every species follows exactly the same routine, and feeding activity can also depend on weather, temperature and the larva's stage of development.
When Are Cutworms Most Active?
Cutworm activity is influenced by local climate, rainfall, temperature, available host plants and the species involved. Some gardeners may notice increased damage during particular planting seasons, but cutworms should not be treated as pests that only occur in spring or early summer.
In South African gardens, it is sensible to monitor vulnerable seedlings whenever new crops are planted, especially where there is a history of caterpillar damage.
Signs of Cutworm Damage in the Garden
Cutworms are particularly frustrating because their damage can appear suddenly. A young plant may be healthy one day and collapsed the next. The most familiar sign is a stem severed close to soil level, but cutworm feeding does not always look exactly the same.
Common Signs to Look For
- Seedlings cut near the base: The stem may be severed at or just above the soil surface.
- Collapsed young plants: A seedling may lie flat while its roots remain in the ground.
- Missing sections of leaves: Some cutworm species feed on foliage rather than cutting through stems.
- Damage appearing overnight: Fresh damage may be discovered during the morning inspection.
- Caterpillars near affected plants: A larva may be found just below the soil surface or beneath nearby debris.
Not every fallen seedling has been attacked by a cutworm. Stem rot, damping-off disease, mechanical damage, other soil-dwelling insects and poor root establishment can also cause young plants to collapse. Check the stem and surrounding soil before deciding on a treatment.
Which Crops Can Be Affected?
Cutworm host plants differ between species. Young vegetable seedlings are often vulnerable, and reported host crops can include:
- Swiss chard and spinach
- Lettuce and other leafy vegetables
- Cabbage and related brassica crops
- Tomatoes and peppers
- Beans and other young legumes
- Various garden flowers and other seedlings
This is a general list, not a guarantee that every cutworm species will feed on every crop. The plants available in a particular garden and the pest species present will influence the damage.
How to Prevent and Manage Cutworms
Managing cutworms starts with accurate observation. If only a few seedlings are affected, physical removal and simple barriers may be enough. When damage is widespread, inspect the growing area carefully and consider whether the problem is being caused by one pest or several.
1. Inspect Seedlings Regularly
Check young plants frequently, particularly during the first weeks after transplanting. Look for severed stems, wilted seedlings, missing leaves and fresh feeding damage. Morning inspections are useful because damage from night-feeding caterpillars may be easier to spot then.
2. Search Around Damaged Plants
If a seedling has been cut through, gently loosen the soil around its base. Search the upper layer of soil, nearby cracks and the underside of plant debris. Cutworms often remain close to the plants on which they have been feeding.
If you find a suspected cutworm, remove it by hand while wearing garden gloves. You can place it in a container for identification or dispose of it responsibly. Avoid leaving removed pest larvae beside the crop.
3. Use Physical Collars Around Seedlings
Cardboard or other suitable collars can help protect individual seedlings from caterpillars that move along the soil surface and cut stems. Place the collar around the plant without squeezing or damaging it, and push the lower edge a little way into the soil to reduce gaps.
Make sure the collar is tall enough to provide a useful barrier and check it regularly as the plant grows. Collars are a preventative measure, not a complete solution: they may not stop larvae already hiding beside or beneath the plant.
4. Manage Weeds and Plant Debris Thoughtfully
Some adult moths lay eggs on vegetation, and young larvae may feed on weeds or other plants before moving to crops. Keeping planting areas reasonably clear of excessive weeds and removing heavily infested plant material can reduce some pest habitat.
However, avoid stripping the garden of all organic matter. Mulch and plant residues also support soil organisms and help protect soil. Manage debris selectively, especially close to vulnerable seedlings, rather than removing every source of habitat for beneficial wildlife.
5. Encourage Natural Predators
Cutworms are part of a wider garden food web. Ground beetles, birds and some parasitic wasps can help suppress caterpillar populations. Protecting beneficial insects and maintaining a diverse garden can contribute to natural pest regulation.
Natural predators rarely eliminate every pest, so combine habitat protection with regular inspection and direct control where necessary.
6. Prepare the Soil Without Excessive Disturbance
Some cutworm larvae and pupae can be exposed when soil is cultivated, making them more accessible to birds and other predators. However, repeatedly turning the soil is not a good long-term pest strategy. Excessive disturbance can damage soil structure and disrupt beneficial organisms.
Where cutworm problems have occurred, inspect the planting area before sowing or transplanting. Remove any larvae you find, manage weeds around the bed and use protective collars for vulnerable seedlings. Choose the least disruptive approach that suits the condition of the garden.
7. Be Careful With Companion-Planting Claims
Plants such as mint, garlic and onions are sometimes recommended as cutworm repellents. However, there is not enough reliable evidence to treat these plants as a dependable way to prevent cutworm moths from laying eggs or to stop larvae from feeding.
You can include herbs and flowering plants in a diverse garden, but do not rely on companion planting alone to protect seedlings. Physical barriers, monitoring and removal of confirmed pests are more practical first steps.
8. Consider Biological or Other Targeted Controls When Needed
If cutworm damage continues despite physical measures, identify the pest as accurately as possible before choosing a control product. Some biological insecticides and other targeted products are designed for particular caterpillar pests, but their effectiveness depends on the active ingredient, the pest species, the application method and whether the larva actually encounters the treatment.
Always follow the product label, including instructions for the crop, target pest, application rate, protective equipment and harvest interval. Avoid broad-spectrum insecticides where possible, because they can also harm beneficial insects and other non-target organisms.
Practical garden approach: Inspect the damaged seedling, search the surrounding soil, remove any confirmed cutworms, protect replacement plants with collars and continue monitoring. This step-by-step approach helps you respond to the actual pest rather than treating the entire garden unnecessarily.
Frequently Asked Questions About Cutworms
1. What are cutworms?
Cutworms are caterpillars of several moth species in the Noctuidae family. Many hide in or near the soil and feed on plants, with some species cutting young seedlings close to ground level.
2. How can I tell if cutworms are damaging my seedlings?
Look for young plants with stems severed near the soil surface. Gently inspect the soil around the damaged plant and beneath nearby debris. You may find a plump caterpillar curled into a C-shape, although this posture alone does not confirm its identity.
3. What plants do cutworms attack?
Host plants vary by species. Some cutworms feed on vegetable seedlings such as Swiss chard, spinach, lettuce, cabbage, tomatoes, peppers and beans, as well as other garden plants.
4. Are cutworms active during the day?
Many cutworm larvae are more active at night and hide in the soil or beneath plant debris during the day. Their activity varies with species and environmental conditions, so daytime activity is not impossible.
5. How do I protect seedlings from cutworms?
Inspect seedlings regularly, search around damaged plants, remove caterpillars you find and use cardboard or other suitable collars around vulnerable stems. Keep the immediate planting area manageable and encourage natural predators.
6. Are cutworms and armyworms the same pest?
No. Both names refer to caterpillars of moths in the Noctuidae family, but they describe different groups of pests and feeding patterns. Some armyworms also have broad host ranges, so they should not be ruled out simply because the damaged crop is Swiss chard or spinach.
7. Do companion plants keep cutworms away?
There is no dependable evidence that commonly suggested companion plants such as mint, garlic or onions will reliably prevent cutworm damage. Use them as part of a diverse garden if you wish, but rely on monitoring and physical protection for vulnerable seedlings.
8. Should I remove every caterpillar I find in my garden?
No. Many caterpillars are harmless or develop into beneficial pollinating moths and butterflies. Identify the insect and check whether it is actually causing damage before removing it. Focus control efforts on confirmed crop pests.
Conclusion: Finding the Pest Behind the Damage
Cutworms are a reminder that not every garden problem is easy to see. A seedling can collapse without an obvious warning, while the caterpillar responsible remains hidden just beneath the soil or under nearby plant debris.
My encounter at Raikana Primary School, while working with Emnes Baloyi, showed me why it is important to investigate before deciding how to respond. Finding the curled caterpillar near the damaged Swiss chard seedling gave us a likely explanation and a practical starting point for protecting the remaining plants.
We could replant, inspect the growing area more carefully and protect vulnerable seedlings as they established themselves. The experience reinforced something important: successful gardening is not just about planting and watering. It also involves observing the small details, recognising problems early and choosing sensible ways to manage them.
We will keep growing, learning and improving the garden. Every challenge is an opportunity to understand the living system beneath and around our crops a little better.