If patches of your lawn have started turning yellow, then brown, in the last couple of weeks — even though you’ve been watering — don’t blame the heat just yet. Late June through August is prime season for southern chinch bugs across the Lowcountry, and they hit St. Augustine grass the hardest.

Chinch bugs are tiny, but they move fast once they find a lawn under heat stress. A small dead patch near your driveway or sidewalk can turn into a dead zone across your whole front yard within a couple of weeks if it’s left alone. Here’s how to tell what you’re dealing with and stop it before it spreads.

1️⃣ Know What You’re Looking For

Southern chinch bugs are the main lawn pest in South Carolina, and St. Augustine grass is their favorite host — though they’ll also feed on zoysia, bermuda, and centipede. Immature nymphs are bright orange with a white band across the back; adults are black with white wings, about the size of a grain of rice. Get down on your knees and part the grass near a yellowing patch and you’ll usually spot them right at the soil line.

2️⃣ The “Drought Damage” That Isn’t

Chinch bug damage almost always gets mistaken for drought stress at first — and that’s exactly why it spreads before homeowners catch it. As the bugs feed, they inject a toxin that turns grass yellow, then reddish-brown, then dead. The damage shows up first in the hottest, driest spots of the yard: next to driveways, sidewalks, and south-facing beds where the sun beats down hardest.

3️⃣ Do the Float Test

Cut both ends off a coffee can, push it a couple inches into the soil at the edge of a suspect patch, and fill it with water. Within five minutes, chinch bugs will float to the surface. If you’re seeing 20-25 or more per square foot, that’s the threshold where treatment is typically needed — anything less and cultural fixes may be enough.

4️⃣ Why Lowcountry Lawns Are Prime Targets

Charleston’s long, humid summers and heavy thatch buildup on well-fed St. Augustine lawns create exactly the conditions chinch bugs thrive in. Lush, heavily fertilized turf with a thick thatch layer gives them cover and an easy food source, and South Carolina sees two to three generations of chinch bugs per year — meaning an untreated infestation just keeps compounding through the summer.

5️⃣ Treating an Active Infestation

Once you’ve confirmed an infestation, a targeted insecticide labeled for chinch bugs is the fastest way to stop the spread — timing and coverage matter more than the product itself. Water the lawn first so the treatment reaches the soil line where the bugs live, and expect to reassess in one to two weeks since damaged grass won’t green back up on its own even after the bugs are gone.

6️⃣ Prevent the Next Wave

Reduce thatch buildup, avoid over-fertilizing in summer, and water deeply but infrequently rather than a light daily sprinkle — all of this makes your lawn less attractive to chinch bugs in the first place. If you’re reseeding or replacing dead patches, look for chinch-bug-resistant St. Augustine cultivars to build in some long-term protection.

💡 Pro Tip: Check the edges of any yellowing patch, not the center — that’s where active chinch bugs are still feeding and where the float test will actually catch them.

Not Sure If It’s Chinch Bugs or Just Summer Stress?

Let Olive Drab Property Services handle it. We know Charleston’s climate — and we know your grass.

Call 843-901-1966