Fall Armyworms: What Homeowners Need to Know to Protect Their Lawns
If your lawn suddenly looks like it’s been hit by a drought—brown patches, thinning grass, or bare stems—there’s a good chance fall armyworms are the culprits. These pests can cause serious damage in a short amount of time, especially in the Southeast. Here’s how to spot them and what you can do to protect your yard.
🐛 What Are Fall Armyworms?
Fall armyworms are caterpillars that feed on over 80 types of plants, but they especially love lush, green, fertilized lawns—particularly Bermuda grass. They also target other grasses like tall fescue, ryegrass, and even vegetable gardens.
📅 When Do They Show Up?
In the Southeast, armyworms typically appear in late July through early fall, but outbreaks can happen as early as mid-April. These pests don’t survive cold winters, so they migrate north each year from warmer regions like Florida and Central America.
🔍 How to Spot the Damage
Armyworm damage can look a lot like drought stress:
Brown patches or thinning grass
Chewed blades that dry out quickly
In severe cases, only tough stems remain
Newly seeded lawns are especially vulnerable—armyworms can kill young grass before it has a chance to establish.
🧬 What Do They Look Like?
Adult moths: Ash-gray with a 1.5-inch wingspan and mottled front wings
Larvae (caterpillars): Up to 1.5 inches long, ranging from green to nearly black
Look for a light-colored “Y” shape on their face
Three thin white stripes behind the head
Small dark spots on each body segment, forming a square pattern near the tail
🔄 Lifecycle at a Glance
Eggs: Laid in clusters on fences, trees, or lawn furniture—hatch in 2–4 days.
Larvae: Feed for 2–3 weeks, causing most of the damage.
Pupae: Burrow into the soil and emerge as moths in 10–14 days.
Moths: Live for 2–3 weeks, laying hundreds of eggs to start the cycle again.
🛡️ What Can Homeowners Do?
Inspect your lawn regularly, especially during late summer.
Look for early signs of damage or caterpillars.
Water and mow properly to keep your lawn healthy and resilient.
Contact a lawn care professional if you suspect an infestation—early treatment can prevent widespread damage.