Grub Worms Florida Lawn Guide: When and How to Treat Them

That sudden brown patch that peels back like loose carpet is one of the most common turf problems we see, and the culprit is often hiding right under your feet. If you’re dealing with a struggling lawn and suspect grub worms, the cause is usually the larvae of scarab beetles feeding on your grass roots. The encouraging part: with the right timing, these pests are very treatable, and your lawn can recover beautifully in our long growing season.

At LandTree (DeAngelo’s Land Services), we care for lawns throughout Orange City, DeLand, Lake Mary, Sanford, Oviedo, Apopka, and the wider Orlando metro. Here’s our field-tested guide to identifying and treating these underground feeders.

What Grub Worms Actually Are

Grub worms are the larval stage of scarab beetles — in Central Florida that mostly means masked chafers and various May or June beetles. The adults you see bumping against your porch light on a summer night are laying the eggs that become the grubs damaging your turf weeks later.

The grubs themselves are plump, C-shaped, creamy-white larvae with brownish heads, usually curled up just below the soil surface. Unlike surface-feeding pests, grubs attack from underneath, chewing through the root system so the grass can no longer take up water or nutrients. That’s why damaged turf lifts so easily — there are barely any roots left holding it down.

Why Central Florida Lawns Are Vulnerable

Our conditions are practically ideal for these pests. The warm zone 9b climate gives beetles a long active season, and our sandy soil is easy for both egg-laying females and developing larvae to move through. Add the heavy June-through-September rains that keep the soil moist, and you have a comfortable nursery for grubs in St. Augustine, bahiagrass, and other warm-season turf common across Volusia, Seminole, and Orange counties.

How to Spot a Grub Problem

Because grubs work below ground, you’ll usually notice the symptoms before the insects. Key warning signs include:

• Irregular brown patches: Areas that yellow and die despite adequate watering.
• Spongy, wilting turf: Grass that looks drought-stressed even when there’s plenty of moisture.
• Turf that lifts like a rug: The signature symptom — grass pulls up in sheets because the roots are gone.
• Nighttime digging: Armadillos, raccoons, and skunks tearing up the lawn to feed on the grubs underneath.

The Tug Test

To confirm grubs, grab a handful of grass in a struggling area and tug. If it peels back like a loose carpet, fold it over and look at the top inch or two of soil. Finding several C-shaped white larvae per square foot tells you grubs are the problem. UF/IFAS guidance notes that more delicate turf like St. Augustine tolerates only about three to five grubs per square foot before treatment is warranted, while tougher grasses such as bahiagrass and bermuda can shrug off more.

The Armadillo Clue

One uniquely Florida tell: if armadillos are digging cone-shaped holes across your yard at night, they’re hunting grubs. That nightly excavation is often the first hint homeowners get that something is feeding below the surface.

When and How to Treat a Grub Worms Florida Lawn

Timing is everything with grubs. Treat too early or too late and you waste product on a life stage that’s hard to kill. Here’s how we approach it.

Target the Young Larvae

The best window is mid-to-late summer, after the eggs hatch and while the grubs are still small and feeding near the surface. Young larvae are far more vulnerable than the large, mature grubs you’ll find in fall, which are tough and ready to burrow deeper for the cooler months.

Water the Product In

Grub control materials are soil-applied and must be watered in so they reach the larvae in the root zone. In our climate, you can sometimes time an application ahead of a predictable summer shower — but applying right before a heavy downpour can wash product away, so always check the forecast and follow the label rate.

Choose the Right Approach

• Curative treatments knock down an active, confirmed infestation when you already see damage.
• Preventive treatments are applied earlier in the season on lawns with a known history of grubs, stopping the next generation before it does harm.

For a lawn that gets hit year after year, a well-timed preventive approach usually beats reacting to damage again and again.

Build a Resilient Lawn

Healthy turf tolerates a few grubs without showing it. Proper mowing height, deep but infrequent watering, and sensible fertilization grow a deep root system that withstands light feeding. In our sandy soil, that strong foundation is your best long-term defense.

Frequently Asked Questions

Are grub worms harmful to people or pets?

No. Grubs only damage grass roots. They don’t bite or pose any health risk to your family or animals.

Can my lawn recover after grub damage?

Usually, yes. Once the grubs are controlled, our warm, rainy season helps the turf fill back in — though severely thinned areas may need reseeding or sod plugs.

How often should I treat for grubs?

Many Central Florida lawns never need annual treatment. Treat when monitoring or damage shows a real problem, and consider prevention only on lawns with a repeat history.

Let LandTree Take a Look

If your grass is lifting like a rug, browning in patches, or attracting nighttime diggers, grubs may be the reason — and we can confirm it quickly. As a veteran-owned company that works in Central Florida soil every day, LandTree (DeAngelo’s Land Services) knows how these pests behave in our zone 9b conditions. Request a free lawn assessment and we’ll diagnose the issue and lay out a simple, effective plan to get your yard thriving again.