Fall Weed Control for Myrtle Beach Lawns: Stopping Winter Weeds in Centipede and St. Augustine

Fall Weed Control for Myrtle Beach Lawns: Stopping Winter Weeds in Centipede and St. Augustine

Lawn Squad of Myrtle Beach • November 2026 • Myrtle Beach, SC

If you are reading this, you may remember last February. Your centipede or St. Augustine was still mostly brown, and suddenly the yard was full of bright green clumps, purple flowers, and that low, ferny weed that turned into spiny burs by March. It seemed like it came out of nowhere.

Most of those weeds started growing the previous fall. That makes fall one of the most important times of the year for weed control on the Grand Strand, and November still matters.

Why Winter Weeds Get a Head Start

Centipede, St. Augustine, zoysia, and Bermuda are warm-season grasses. As November temperatures cool, they slow down, and frost pushes them into dormancy. That leaves open space and sunlight just as winter weeds begin to germinate.

Those weeds grow slowly through winter, then surge in late winter and early spring, flowering and setting seed before the warm-season grass greens up.

The Weeds We See Most

Annual bluegrass, or poa annua, is a bright green, clumpy grass that shows up in dormant lawns and produces seed heads in late winter.

Henbit has square stems and small purple flowers. Chickweed forms low mats with small white flowers, especially in shaded, damp areas.

Lawn burweed, sometimes called spurweed, is the one families notice most. It looks harmless and ferny in winter, then develops spiny burs in spring that stick to bare feet and pets.

Florida betony is a perennial that grows in the cooler months, with square stems and white, segmented tubers underground that look a bit like rattlesnake rattles. It is common in coastal Carolina lawns and difficult to control.

Pre-Emergent Timing

A pre-emergent herbicide forms a barrier in the top layer of soil that stops many weed seeds from emerging. It does not control weeds already growing or perennial weeds like Florida betony that spread from tubers.

For winter annuals on the Grand Strand, the best time for a fall pre-emergent is generally early fall, from mid September through October, before most of them germinate. A November application can still help with later-germinating weeds.

Most pre-emergents also stop grass seed and can affect new sod or plugs, so timing matters if you plan repairs.

Post-Emergent Control

Post-emergent herbicides target weeds that are already growing. Here is what we have found works best. Treat young winter weeds on mild days in late fall and winter, while they are small and actively growing, rather than waiting until spring. Controlling lawn burweed before its burs form in spring is especially important. Florida betony usually takes repeated treatments while it is actively growing.

Centipede and St. Augustine Are Sensitive

Centipede and St. Augustine are sensitive to some herbicides that are safe on Bermuda and zoysia. Some products can injure or kill them, especially in warm weather. Always read the label carefully, choose products labeled for your grass type and the weeds you are targeting, and follow temperature limits.

A Thick Lawn Is the Best Defense

Weeds fill empty space. Keep centipede at around one and a half to two inches, St. Augustine at three and a half to four inches, and zoysia and Bermuda at their recommended heights. Avoid scalping in fall. Keep fall fertilizer light and appropriate for your grass, since overfeeding centipede in particular can thin it out and invite weeds.

Water Wisely

Overwatering in fall encourages weeds like annual bluegrass and chickweed, along with dollarweed and sedges that linger from summer. Cut back irrigation as temperatures cool, water only when the lawn needs it, and water early in the morning.

Watch the Thin Spots

Winter weeds show up first where the lawn is thin: under pines and oaks, along beds and walkways, in areas damaged by summer heat, insects, or disease, and in sandy spots that dry out fast. Those are the areas to watch.

Shade Under Pines

Many Grand Strand properties sit under tall pines and live oaks. Centipede and Bermuda thin out in shade, leaving room for chickweed and annual bluegrass. Shade-tolerant St. Augustine varieties, pine straw beds, or thinning the canopy can help in the shadiest areas.

Weed and Feed Products

Weed and feed products combine fertilizer and herbicide. In fall, the fertilizer half is rarely appropriate, especially on centipede, and the herbicide half may not match the weeds you have. Treating weeds and feeding the lawn as separate steps usually works better.

Sedges and Dollarweed

Sedges and dollarweed are warm-season problems that thrive in wet soil. They slow down in fall and are best treated in late spring and summer. Reducing overwatering helps keep them in check year-round.

Beds and Edges

Weeds in landscape beds and along driveways spread seed into the lawn. Keeping beds mulched with pine straw or bark and weeding regularly reduces seed pressure.

Keep Products Away From Water

Many Myrtle Beach properties border ponds, swashes, and marsh. Keep herbicides and fertilizers away from the water’s edge and storm drains.

Salt Spray Near the Ocean

Oceanfront and near-ocean lawns face salt spray, which can stress and thin turf, especially centipede, which has relatively low salt tolerance. Thin, salt-stressed areas are easy targets for winter weeds. St. Augustine and some zoysia and Bermuda varieties tolerate salt better, which is worth considering when repairing areas near the dunes.

Spot Treat Scattered Weeds

In lawns with only scattered weeds, spot treating saves product and reduces stress on centipede and St. Augustine. Broadcast treatments make more sense when weeds are widespread.

Hand Pulling Has Limits

Pulling works for a few young henbit or chickweed plants, but not for Florida betony, whose underground tubers regrow, or for lawn burweed once it has spread across the lawn.

Keep Records

Note which weeds show up where. Those notes make next fall’s pre-emergent timing and spot treatments more targeted.

Seasonal and Rental Properties

If your Grand Strand home is a second home or rental, scheduling fall and winter weed treatments while you are away keeps the lawn from getting ahead of you. Coordinating irrigation adjustments with those visits helps too.

Mowing Dormant Lawns

Mowing a dormant lawn once or twice in late winter can cut off weed seed heads before they spread, especially annual bluegrass. It does not kill the weeds, but it reduces next year’s seed.

What to Expect

Fall weed control does not mean zero weeds. It means far fewer, smaller weeds that are easier to manage. Perennial weeds like Florida betony often take more than one season of consistent treatment.

What a Clean Spring Looks Like

Imagine this. It is March. Neighboring lawns are full of poa clumps, henbit, and burweed. Yours is greening up with far fewer weeds, and nobody is pulling burs out of the kids’ feet after a day in the yard.

What to Do Next

If you missed the early fall pre-emergent window, treat young winter weeds, lawn burweed, and Florida betony on mild days with products labeled for your grass type. Keep mowing at the right height, cut back irrigation, keep fall fertilizer appropriate for your grass, and plan a pre-emergent for mid September next year.

If you would rather have someone else handle the timing decisions, product selection, and application for your Myrtle Beach lawn, we are here for that. Lawn Squad of Myrtle Beach serves homeowners across the Myrtle Beach area. Visit lawnsquad.com to request a free quote. Our VitaminLawn program is built for the grass types, soils, and weather patterns we deal with here.

Here is what to expect. We will look at your grass, talk through how your lawn handled this year, and explain what we would apply before winter and why. If your lawn does not need a late-season application, we will tell you that honestly.