Why Dollarweed is Taking Over Charleston Lawns — And How to Stop It

If you've noticed round, shiny, bright-green leaves spreading through your lawn — especially in low, damp areas — you're almost certainly dealing with dollarweed. Also known as pennywort, dollarweed is the single most common and most complained-about weed problem for homeowners in Charleston, Daniel Island, Mount Pleasant, and across the South Carolina Lowcountry.

The bad news: dollarweed is aggressive, persistent, and specifically adapted to thrive in exactly the conditions that define most Charleston yards. The good news: with the right professional treatment program, it can be eliminated and kept out for good.

What Is Dollarweed?

Dollarweed (Hydrocotyle spp.) is a perennial weed native to warm, wet climates. Its name comes from its distinctive round, silver-dollar-shaped leaves with scalloped edges and a stem that attaches to the center of the leaf rather than the edge — making it easy to identify. It spreads aggressively through both seeds and an extensive underground rhizome system, which is why it keeps coming back even after you pull it up by hand or apply generic weed killers.

Why Dollarweed Thrives in the Charleston Area

Dollarweed is not a problem you can simply water less your way out of — though reducing unnecessary irrigation helps. The Lowcountry's climate, soil composition, and the prevalence of irrigation systems in neighborhoods like Daniel Island and Mount Pleasant create conditions that are essentially tailor-made for dollarweed. Specific factors include:

• High rainfall — Charleston averages over 50 inches of rain per year, keeping soil moisture levels consistently high
• Warm year-round temperatures — Dollarweed doesn't go fully dormant in Charleston winters the way it does in cooler climates, giving it a head start each spring
• Irrigation systems — Automatic irrigation systems that water more than necessary are one of the biggest contributors to dollarweed outbreaks in newer neighborhoods
• Low-lying lots — Many properties in the Lowcountry have drainage challenges that result in areas of standing or slow-draining water — dollarweed's favorite habitat
• Sandy soils — While sandy soil drains quickly in some areas, the Lowcountry's clay-sand mix can retain surface moisture in ways that favor dollarweed over desired turf grasses

Why Pulling It Up Doesn't Work

Many homeowners try to hand-pull dollarweed and find that it comes back within weeks. This happens because dollarweed spreads through underground rhizomes — horizontal root-like stems that can extend several feet from the visible plant. When you pull the top growth, the rhizome system below remains fully intact and quickly produces new shoots. Unless you remove every fragment of the rhizome system — which is essentially impossible by hand in an established infestation — the plant regrows.

Over-the-counter post-emergent herbicides often provide only partial or temporary control, particularly on mature dollarweed with an established rhizome network. Professional-grade products and timing make a significant difference in effectiveness.

The Right Approach: Pre-Emergent + Post-Emergent Treatment

The most effective way to control dollarweed in a Charleston lawn is a combination of strategically timed pre-emergent and post-emergent treatments — which is exactly what Shield Pest Solutions' weed control program delivers across eight applications per year.

• Pre-emergent treatments — Applied in late winter and early spring before dollarweed seeds germinate, preventing new plants from establishing
• Post-emergent treatments — Applied to actively growing dollarweed using professional-grade selective herbicides that target the weed without harming your desired turf grass
• Repeat applications — Because of the rhizome system, multiple treatments over a season are typically needed to exhaust the underground reserves and achieve full control
• Fertilization — A thick, healthy, well-fertilized lawn is one of the best long-term defenses against dollarweed. Dense turf simply doesn't give dollarweed the bare soil and sunlight it needs to establish

Other Common Weeds in Charleston Lawns

While dollarweed is the most prevalent, Charleston-area lawns deal with several other aggressive weed species:

• Chamberbitter — A summer annual that resembles a miniature tree and spreads prolifically by seed in summer months
• Crabgrass — A warm-season annual grass weed that germinates in spring and can take over thin or stressed lawns quickly
• Nutsedge (Yellow & Purple) — Often mistaken for grass, nutsedge grows faster than turf and is notoriously difficult to control without professional products
• Clover — White and red clover spreads through lawns that are low in nitrogen, making fertilization an important part of control
• Torpedo grass — An extremely aggressive perennial grass weed common in Lowcountry lawns near water features

What You Can Do to Help

Alongside professional treatment, a few practices can help reduce dollarweed pressure in your Charleston lawn:

• Reduce irrigation frequency — Water deeply but less frequently to encourage deep root growth in turf while reducing the surface moisture dollarweed prefers
• Improve drainage — Address low spots and drainage issues where water pools after rain
• Mow at the right height — Keep St. Augustine at 3.5–4 inches and Bermuda at 1–1.5 inches; taller turf shades soil and reduces weed germination
• Don't skip fertilization — A consistently fed lawn stays thick and competitive against weeds like dollarweed

Shield Pest Solutions has been eliminating dollarweed and other Lowcountry lawn weeds for homeowners across Charleston, Daniel Island, and Mount Pleasant for over 10 years. Our 8-application program keeps weeds out season after season while building the healthy lawn your property deserves.