Dollarweed in Warm-Season Lawns: Complete Guide
Dollarweed thrives in Florida's wet conditions, spreading aggressively through over-watered lawns. Understanding its moisture dependency is key to long-term control.
What Dollarweed Looks Like
Dollarweed (Hydrocotyle spp.), also called Pennywort, is one of Florida's most common and persistent lawn weeds. It's instantly recognizable by its round, shiny, silver-dollar-sized leaves that attach to the stem at the center of the leaf (like an umbrella). This central attachment point (peltate structure) distinguishes Dollarweed from similar-looking weeds.
The leaves are typically 1-2 inches in diameter, glossy green, and have scalloped edges. They grow on slender stems that connect to an extensive underground rhizome system. This rhizome network allows Dollarweed to spread rapidly, forming dense mats that can overwhelm grass. Even a small piece of rhizome left in the soil can regenerate into a new plant.
Dollarweed produces small, inconspicuous white flowers in summer, but it spreads primarily through its aggressive rhizome system rather than by seed. The plant thrives in moist or wet conditions and is particularly invasive in over-watered lawns, poorly drained areas, and landscapes with irrigation issues. It often appears first in low spots where water collects.
The presence of Dollarweed is a strong indicator that your lawn is receiving too much water. Reducing irrigation is essential for long-term control, as herbicides alone won't eliminate Dollarweed if wet conditions persist. In Florida's rainy summer season, Dollarweed often explodes in growth, making it seem impossible to control without addressing the underlying moisture issues.
Warm-Season Grasses Affected
When It Strikes in the South
Dollarweed is active year-round in Florida but grows most aggressively during the rainy summer season (June-September) when moisture is abundant. It may die back slightly during winter dry season but quickly rebounds when irrigation or rainfall increases. The best treatment window is spring or fall when the plant is actively growing but not stressed by summer heat.
How to Confirm Dollarweed
- 1Look for round, glossy, silver-dollar-sized leaves
- 2Check if leaves attach to stems at the center (umbrella-like) rather than at the edge
- 3Note the scalloped edges on the round leaves
- 4Observe if the weed is concentrated in wet areas or low spots
- 5Try to pull - extensive rhizome network should be visible
Treatment Steps for Dollarweed
- 1
FIRST, reduce irrigation - Dollarweed cannot be controlled long-term without addressing moisture issues
- 2
Apply a post-emergent herbicide containing 2,4-D, triclopyr, or metsulfuron when Dollarweed is actively growing
- 3
Use a surfactant to help herbicide penetrate the waxy leaf coating
- 4
Treat in spring or fall for best results - avoid summer heat stress
- 5
Make follow-up applications every 2-4 weeks until control is achieved
- 6
Improve drainage in low-lying areas where Dollarweed persists
Recommended Products
Southern Ag Atrazine Weed Killer
Effective pre and post-emergent for Dollarweed control in St. Augustine and Centipede lawns
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Professional herbicide with excellent Dollarweed activity safe for warm-season grasses
View on Amazon →Image Kills Nutsedge Concentrate
Contains imazaquin for effective Dollarweed control in most lawn types
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Prevention Tips
- ✓Reduce irrigation frequency - water deeply but infrequently to promote deep grass roots
- ✓Improve drainage in low-lying areas where water collects
- ✓Maintain healthy, thick turf that can outcompete Dollarweed
- ✓Address irrigation system issues (broken heads, over-coverage) that create wet spots
- ✓Use pre-emergent herbicides containing atrazine in late winter to prevent spring emergence
- ✓Fill low spots with soil to prevent water pooling
Frequently Asked Questions
Why won't my Dollarweed go away even after herbicide treatment?▼
Dollarweed herbicide treatment will fail if moisture conditions aren't corrected. This weed's extensive rhizome system stores energy and allows it to regrow repeatedly in wet conditions. Reduce irrigation, improve drainage, and be patient - multiple herbicide applications combined with drier conditions are needed for lasting control.
Is Dollarweed the same as Water Pennywort?▼
Yes, Dollarweed and Pennywort are common names for Hydrocotyle species. Several species occur in Florida with similar appearance and behavior. All require moist conditions and respond to the same control strategies.
Will pulling Dollarweed get rid of it?▼
Hand-pulling is rarely effective because of Dollarweed's extensive rhizome network. Any rhizome fragments left in the soil will regenerate. Pulling may provide temporary control of visible plants but won't eliminate the underground rhizome system. Herbicides combined with reduced moisture are more effective.
Why does Dollarweed grow in my lawn but not in my neighbor's?▼
You likely have more soil moisture than your neighbor from overwatering, poor drainage, or irrigation issues. Compare your watering schedule - you may be irrigating more frequently or for longer durations. Dollarweed is a biological indicator of excess moisture.
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