Sod webworms turn a healthy lawn into thin, brown, scalped-looking patches almost overnight, and the first clue is often tiny moths fluttering up when you mow. If you are trying to figure out how to get rid of sod webworms, the right answer starts with spotting the damage early, then hitting the larvae in the grass before they strip more blades. The good news is that you can stop them with a simple inspection, a fast treatment, and a few lawn care adjustments.
How to tell sod webworms are the problem
Sod webworms are the caterpillar stage of small lawn moths. The larvae chew grass blades at night and hide in the thatch during the day, which is why damage shows up before the pests do. Look for irregular brown or pale patches, grass blades clipped near the crown, and tiny green or tan pellets on sidewalks, patios, or the soil surface.
One fast check is the soap flush. Mix 2 tablespoons of liquid dish soap in 2 gallons of water, pour it over about 2 square yards of suspect turf, and wait 5 to 10 minutes. If sod webworms are present, small striped or mottled caterpillars will crawl to the surface.
Damage that points to webworms
Webworm damage looks like grazed grass, not drought stress. The turf turns thin and ragged first, then patches expand as more blades are eaten. In a bad infestation, the lawn can look like it was mowed too short in random spots.
If you see moths flush up from the grass at dusk or when the mower passes, that is another strong clue. Adult moths do not damage the lawn, but they lay the eggs that lead to the next wave of feeding larvae.
Best treatment for sod webworm infestations
The best treatment for sod webworm is a fast, targeted insecticide applied to active larvae, plus good watering to get it into the thatch and root zone. For most homeowners, a product labeled for sod webworms on lawns that contains bifenthrin, carbaryl, lambda-cyhalothrin, or chlorantraniliprole is the right choice. Read the label and use it only on turfgrass listed on the product.
If you want the cleanest knockdown on active feeding, choose a liquid or granular lawn insect control labeled for sod webworms and water it in according to the label directions. For larger lawns, granular products are easier to distribute evenly. For smaller problem spots, a hose-end or pump sprayer gives tighter coverage.
What to use on the lawn
Use a lawn insecticide labeled for sod webworms, not a general bug spray made for patios or kitchens. Indoor sprays do not belong on turf, and they will not reach the larvae living in the thatch. Products for lawns are designed to move into the grass canopy where the caterpillars feed.
If you want a lower-impact preventive option, chlorantraniliprole works well as a lawn treatment when applied before heavy feeding starts. If you already see active damage and larvae, a contact product such as bifenthrin, lambda-cyhalothrin, or carbaryl gives faster visible results.
How to treat sod webworms step by step
Apply treatment at dusk or early evening, when the larvae come up to feed. This puts the product where the pests are active and reduces rapid breakdown from sunlight. Keep pets and children off the lawn until the product dries and, if the label says so, until the lawn has been watered in.
- Mow the lawn a day before treatment so the product can reach the soil surface and thatch.
- Water the turf lightly before application if the grass is very dry, so the spray or granules settle evenly.
- Mix the product exactly as the label directs, or calibrate the spreader for the labeled rate.
- Apply evenly over the affected area, overlapping passes so you do not miss strips.
- Water in the treatment only if the label requires it.
- Leave the area alone for the label-recommended reentry time.
Focus on the whole damaged section, not just the brown center. Larvae spread into the surrounding healthy turf, and treating only the dead-looking center leaves the edge population behind.
How to get rid of sod webworms in lawn without repeating the problem
Once the infestation is controlled, the lawn needs a few changes so it does not become a repeat target. Webworms thrive in thick thatch, stressed turf, and uneven watering. A lawn that stays dense and healthy can handle light feeding without showing serious damage.
Watering and mowing that help
Water deeply, about 1 inch per week total, and do it in a single early-morning soaking instead of frequent shallow watering. This helps the grass recover and makes the lawn less stressed. Keep mowing at the correct height for your grass type, and never remove more than one-third of the blade at a time.
If thatch is thicker than half an inch, dethatch or power rake in the right season for your turf. Webworms hide in that layer, and heavy thatch protects them from sprays and granules. Aeration also helps water and treatment move into the root zone.
How to get rid of sod webworm moths
If you are asking how to get rid of sod webworm moths, the direct answer is that you reduce the larvae that produce them. Adult moths do not feed on the grass, so spraying visible moths gives short-lived results and does not solve the lawn problem. Killing the caterpillars breaks the cycle.
What actually reduces moth activity
Use a lawn insecticide labeled for sod webworms during the larval stage, then keep nighttime lights off near the lawn when moth flights are heavy. Moths are drawn to bright exterior lights, which brings more egg-laying adults close to the turf.
If your lawn had a heavy outbreak this season, treat promptly at the first sign of small feeding patches next time. Early larval control means fewer moths emerge later, and fewer eggs get laid in the grass.
When to treat for sod webworms
The best time to treat for sod webworms is when you see fresh feeding damage and confirm larvae with a soap flush. In many areas, that means late spring through summer, with the highest pressure in warm, humid periods. Treating after the lawn is already mostly dead wastes product, because dead grass will not recover from complete defoliation.
If the infestation is light, spot treat the damaged areas plus a buffer around them. If you find larvae in multiple parts of the yard, treat the entire lawn in one pass so surviving caterpillars do not keep spreading.
Frequently Asked Questions
How do I know if I have sod webworms or grubs?
Sod webworms chew the grass blades, leaving ragged, scalped-looking turf and small pellet-like droppings. Grubs feed on roots, so the turf loosens and peels up like a carpet. A soap flush brings webworms to the surface, while grubs are found below the turf in the soil.
Do I need to spray at the first sign of moths?
No. The moths are the adult stage, and they are a sign that eggs have been laid or will be laid soon. Treat when you find larvae and active feeding, because that is the stage that damages the lawn and responds best to control.
Can I use a home remedy for sod webworms?
Soap flushes help you find them, but they are not a full treatment. For control, use a turf insecticide labeled for sod webworms and apply it to the lawn according to the label. Home sprays made for indoor pests do not solve a lawn infestation.
How fast will the lawn recover?
If the grass is still alive at the crown, new growth fills in after the larvae stop feeding and the lawn gets proper water and mowing. Severely stripped spots need reseeding or sod patching after the pest problem is controlled.