Cutworms are the larvae of various species of night-flying brown or gray moths. Cutworms chew the tender, young stems, and leaves of almost all vegetable crops. Control cutworms early in the season by handpicking, trapping, or exposing them to predators such as birds.
Cutworms feed at night on young plants, usually severing the stem at or just below the soil line causing the plant to fall over. Cutworms can completely consume seedlings. During the day, cutworms rest in the soil at the base of plants; they are usually found curled up into a C-shape.
Cutworms emerge in spring to feed at night. The moths are brownish or gray with 1½-inch wingspans. The larvae are plump, gray or brown, hairless caterpillars often with shiny heads.
One cutworm can chew through the stems of several seedlings and transplants in one night. Cutworms also climb on plants to chew leaves and buds. Several generations of cutworms can live in a garden in one growing season.
Cutworm larvae are shiny, smooth gray, or dull brown caterpillars, 1 to 2 inches long, with shiny heads. Some cutworms are variegated with yellow spots down the center of the back. When disturbed, cutworms curl into a C-shape.
Moths that lay cutworm eggs are brown or gray with a wingspan of about 1½ inches and stripes on their forewings. The moths fly at night and lay white eggs on host plants or in the soil. Newly hatched larvae feed on vegetable and flower leaves and then retreat into the soil during the day where they curl beside plant stems. Cutworms can chew through stems or completely consume small seedlings. They can climb into plants and eat leaves and buds.
Cutworms can be found throughout the United States and Canada. In far northern regions, one or two generations of cutworms can be expected each year; in southern regions, there can be six generations or more per year. Eggs hatch in 5 to 7 days and larvae feed on grass and plants for 3 to 5 weeks before pupating in the soil. Eggs and pupae can overwinter in the soil.
Adult cutworm moths emerge in spring after overwintering as pupae. They lay eggs in the soil or on grass blades. Eggs hatch 5 to 7 days later. Then larvae cutworms feed on seedlings, grass, and plant leaves for 3 to 5 weeks before burrowing into the soil to pupate.
Autumn sage (Salvia greggii) is a favorite for gardens thanks to its low maintenance nature and vivid, long-lasting blooms that attract pollinators. However, these plants can occasionally be plagued by cutworms that damage stems and leaves. Getting rid of these pesky pests takes some persistence, but is doable through organic, non-toxic approaches. In this comprehensive guide, we’ll explore effective strategies for protecting autumn sage and ridding plants of cutworms for good.
What are Cutworms?
Before diving into solutions, let’s quickly cover what cutworms are and how to identify an infestation.
Cutworms are the caterpillar or larval stage of various moth species in the Noctuidae family They earn their name from their habit of chewing through and cutting down young seedlings and tender new growth of plants right at soil level
These pests are most active at night and spend days curled up just below the surface of soil near host plants, An infestation can be identified by
- Stems of new growth severed right at soil line
- Chewed or missing leaves on new shoots
- Presence of plump green, brown, gray or striped caterpillars up to 2 inches long hiding near plants during day
- Evidence of leaf notching from nighttime feeding
Catching cutworm damage early is key to saving autumn sage plants. Now let’s explore smart, organic approaches to get rid of these pests for good.
Remove Cutworms Manually
One of the most effective methods for immediate relief is to manually remove the cutworms. Since they hide near the base of plants during the day, locate and destroy them by:
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Searching through the top few inches of soil for curled up caterpillars.
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Digging near damaged plants using trowels or narrow tools to uncover pests without disturbing roots.
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Pick cutworms off plants and drop into jars of soapy water or seal in plastic bags to dispose of.
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Check under mulch, leaves, boards or any debris around plants that could shelter pests.
While labor intensive, this hands-on approach can eliminate a good portion of cutworms and bring rapid relief when infestations are severe. Just be sure to wear gloves and watch for the caterpillar’s “biting” end!
Apply Beneficial Nematodes
An organic, biological weapon against subsurface cutworms are beneficial nematodes. These tiny roundworms are safe for plants and humans, but prey on soil-dwelling insects.
To use them against cutworms:
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Water soil thoroughly around damaged autumn sage first.
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Apply nematodes labelled for caterpillar control directly to moist soil around plants.
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Reapply every 2-3 weeks until pests are under control. The nematodes will kill cutworms in soil.
This microbial method is extremely effective and safe for an eco-friendly garden.
Encourage Natural Predators
Another organic tactic is attracting natural predators to feast on cutworms. Birds, reptiles, and beneficial insects will target these juicy caterpillars.
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Install bird houses and baths to invite insect-eating birds into the garden
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Avoid pesticides so ground beetles, spiders and ants can thrive
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Plant nectar sources like dill, fennel, and cosmos to draw in parasitic wasps
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Release green lacewings or install bat houses
By thinking like a bug and creating an inviting habitat, nature will help control cutworms for free!
Use Physical Barriers
Since cutworms travel underground, physical barriers can block their access to plants.
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Wrap cardboard, aluminum foil or metal sheeting 2-3 inches above and below soil around autumn sage stems.
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Place cutworm collars, bottomless paper cups, or receptacles topped with fine mesh 2 inches deep around plants.
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Cover soil with floating row covers to keep moths from laying eggs near plants.
These handmade guards provide instant protection against cutworms reaching vulnerable plant parts.
Apply Cornmeal
A folklore trick for killing caterpillars is sprinkling cornmeal around autumn sage plants. The cutworms eat the cornmeal, which then expands in their stomach leading to death.
To try this home remedy:
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Sprinkle a thin layer of cornmeal around the base of plants and lightly work into soil.
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Reapply after rain or watering. The abrasive grains will take down cutworms from the inside out.
This inexpensive pantry item is readily available and safe for gardens.
Interplant with Deterrent Plants
Certain plants can deter or confuse cutworm moths from laying eggs around vulnerable plants. Interplant autumn sage with these cutworm-confusing options:
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Alliums like onions, garlic, leeks and chives
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Daffodils
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Dill
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Marigolds
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Nasturtiums
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Petunias
The strong scents mask plants like autumn sage and make them harder targets. Plus, pollinator-attracting flowers make a beautiful companion planting!
Time Plantings Carefully
Since cutworm damage is most severe on young plants, avoid setting out new transplants during peak activity.
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In spring, delay planting until soil warms thoroughly as soil temps below 60°F fuel cutworms
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In fall, get plants established well before first frost
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Place protective covers over new transplants for 1-2 weeks after planting
This allows them to mature past the vulnerable seedling stage most prone to cutting.
Maintain Vigilant Field Scouting
The best defense is a good offense when it comes to cutworms. Stay alert and be proactive:
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Regularly inspect both established and young autumn sage closely for early signs of damage. Catch infestations before they escalate.
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Search for caterpillars at bases of plants and under debris. Remove immediately by hand or use nematodes.
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Act quickly at the first signs of chewed leaves or severed stems to prevent total loss of plants.
Consistent monitoring and targeted removal can keep cutworms from getting out of control.
While dealing with cutworms requires persistence, organic and home remedies can successfully protect autumn sage plants from these sneaky saboteurs. Combining preventive planting strategies and vigilant field scouting with targeted, eco-friendly pest removal provides the best defense. With a multi-tactic approach, gardens can ward off cutworms and enjoy autumn sage’s vibrant, pollinator-attracting blooms without toxic chemicals.
Feeding habits and damage
Cutworms chew stems and leaves of young plants. They severe seedlings and leave them lying on the ground. They sometimes consume entire small plants.
Protect seedlings and transplants from damage by using cutworm collars. A collar can be made of cardboard, plastic, or a small tin can with both ends removed. Press the collar an inch into the soil, leaving an inch or two exposed. The collar will exclude cutworms from the plant stem. Cultivation can expose cutworms to cold and birds. A drench containing Steinernema parasitic nematodes can be poured into planting beds; the nematodes will attack cutworms.
Put collars made of paper, cardboard, plastic, aluminum foil, or tin around transplant stems at planting. Bottomless Styrofoam cups, waxed-coated paper cups, or yogurt cups can be placed around seedlings. Push the collars into the soil until about half of the collar is below soil level and at least 2 inches above soil level, then check to make sure there are no cutworms inside the collar. Leave the collars in place all season or until plants are too large to be damaged by cutworms.
Cutworms- How to prevent and control it
FAQ
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