Florida Lawn Weeds to Watch for in Winter (And How to Prevent Them)

Introduction

Florida lawns stay green longer than those in most states, but winter still brings its own set of challenges especially when it comes to weeds. As temperatures cool and rainfall drops, many warm-season grasses slow their growth. Unfortunately, winter weeds do the opposite: they thrive.

Because winter weeds germinate in fall and explode during the dry season, this is the time Florida homeowners must pay close attention. Left untreated, these weeds can take over your lawn, steal nutrients, and set thousands of seeds that will haunt you all spring.

Here are the most common winter weeds in Florida and how to stop them before they become a bigger problem.

Why Winter Weeds Are a Problem in Florida

Winter weeds are more than just an eyesore. They create a cycle that weakens lawns year after year.

1. They Compete With Dormant or Slow-Growing Grass

St. Augustine, Zoysia, Bermuda, and Bahia all grow slower in winter. Weeds take advantage of this lull to spread.

2. They Spread Seed Quickly

Most winter weeds germinate in fall and drop seeds by early spring. One weed can produce hundreds of seeds.

3. They Attract Pests

Some weeds harbor insects like aphids, which can spread to ornamentals.

4. They Make Lawns Patchy and Thin

Once weeds take hold, lawns struggle to regrow in bare areas during spring.

The Most Common Florida Winter Lawn Weeds

Here are the weeds you’re most likely to see in your yard during the dry season.

1. Annual Bluegrass (Poa annua)

A bright green, fast-growing grassy weed. It stands out sharply against dormant turf.

Why it’s a problem: Produces large seed heads and spreads aggressively.

2. Chickweed

A low-growing, fast-spreading winter annual with small white flowers.

Danger: Forms thick mats that choke your turf.

3. Clover (White & Red Clover)

Common in lawns with thin areas or low nitrogen.

Bonus indicator: Clover in the lawn often means your soil needs fertilizing.

4. Henbit

A tall weed with purple flowers that grows quickly in cool weather.

Why it thrives: Loves disturbed soil and moisture-retentive areas.

5. Florida Betony (Rattlesnake Weed)

A major issue in Central and North Florida. Recognizable by its segmented, white tubers.

Why it’s notorious: Extremely difficult to eradicate once established.

6. Wild Geranium

A small flowering broadleaf that spreads in shady areas.

7. Dollarweed

Although more common in wet summer months, dollarweed also appears in winter where irrigation is too high.

Why Winter Is the Best Time to Prevent These Weeds

The key to weed control is stopping weeds before you see them.

1. Cool Soil Activates Weed Germination

As temperatures fall below 70°F, many winter weeds begin sprouting.

2. Lawns Slow Down, Leaving More Openings

Less growth means more sunlight reaches weed seeds.

3. Dry Season Means Clear Visibility

Weeds are easier to spot during the dry season when grass grows slower.

How to Prevent Winter Weeds in Florida

Prevention is always easier than treatment. Here’s what Florida homeowners can do.

1. Apply a Fall Pre-Emergent Herbicide

This is the most important step. Apply between late September and November, depending on your zone.

Recommended pre-emergents:

• Prodiamine

• Pendimethalin

• Dithiopyr

These stop seeds from germinating.

2. Mow the Lawn at the Correct Height

Proper mowing keeps your grass dense and prevents weed light exposure.

Ideal mowing heights:

• St. Augustine: 3.5–4 inches

• Zoysia: 2–2.5 inches

• Bermuda: 1–2 inches

• Bahia: 3–4 inches

3. Water Properly During the Dry Season

Overwatering encourages weeds like dollarweed and sedges. The goal: ½ inch of water, twice weekly.

4. Pull Weeds Early

Hand-pulling is effective for small patches, especially before weeds flower or seed.

5. Fertilize at the Right Time

Don’t fertilize too early in winter. Instead, use a late fall fertilizer or wait until spring.

6. Improve Lawn Density

Dense, healthy turf is the best weed prevention.

Recommended steps:

• Aeration

• Topdressing

• Overseeding (Bermuda & Zoysia only)

How to Treat Winter Weeds Once They Appear

Sometimes weeds still pop up even with prevention. Here’s how to eliminate them safely.

1. Use Selective Herbicides

Choose herbicides safe for your specific turfgrass.

Examples:

• Atrazine: Safe for St. Augustine & Centipede

• Celsius: Safe for most warm-season grasses

• Image: Works well on dollarweed & sedges

2. Spot-Treat Problem Areas

Avoid blanket spraying unless absolutely necessary during winter.

3. Improve Soil Health

Healthy soil reduces weed pressure. Consider:

• Adding compost

• Checking pH levels

• Improving drainage

4. Reduce Irrigation

Too much water = weed paradise.

Areas of the Yard Most Prone to Winter Weeds

Different weeds thrive in different conditions.

Shade Areas

• Dollarweed

• Wild geranium

Overwatered Sections

• Dollarweed

• Sedge varieties

Thin or Compacted Grass

• Clover

• Chickweed

• Henbit

High-Traffic Zones

• Poa annua

• Betony

Final Thoughts

Winter weeds are one of the biggest hidden threats to Florida lawns. By spotting them early and taking the right preventive steps you can keep your turf dense, healthy, and green year-round.

If you need help treating winter weeds, applying pre-emergent, or improving lawn density, our team is here to help. Winter is the perfect time to get ahead of weeds before they take over in spring!