If your lawn has patches of round, shiny leaves that look like little lily pads, you have dollarweed. It is one of the most common complaints we hear from homeowners in Mount Pleasant, James Island and across the Lowcountry. Learning how to get rid of dollarweed starts with understanding why it showed up in the first place. Spraying alone rarely solves it. Fixing the moisture that feeds it, then treating it at the right time with a product that is safe for your grass, is what actually works.
What dollarweed is and how to identify it
Dollarweed, also called pennywort, is a perennial broadleaf weed. It spreads by underground runners called rhizomes and by above ground stems, and it can also come back from seed. Look for these features:
- Round, bright green, glossy leaves, roughly the size of a coin or larger
- Scalloped edges on the leaf
- The leaf stem attached to the center of the leaf, like an umbrella
- Clusters of small white flowers in summer
It is easy to confuse with dichondra or ground ivy. Dichondra has kidney shaped leaves with the stem attached at the edge. Ground ivy has square stems and a minty smell when crushed. The center attached stem is the giveaway for dollarweed.
Why dollarweed takes over Lowcountry lawns
Clemson Extension is clear on this point. Dollarweed thrives in excessively moist soil. In coastal South Carolina, that moisture usually comes from one of three places:
- Irrigation that runs too often. Short daily cycles keep the surface wet all the time. Clemson research found that simply reducing irrigation frequency significantly cut dollarweed.
- Poor drainage. Low areas near downspouts, flat new construction lots and yards with a high water table stay damp after every storm.
- Thin turf. Mowing too low, shade and compaction all leave openings for dollarweed to fill.
A lawn that gets about an inch of water per week, rain included, generally needs no extra irrigation. If your system runs every morning in July while it is also raining every afternoon, the dollarweed will thank you.
How to get rid of dollarweed step by step
Step 1: Cut back the water
Before anything else, adjust your irrigation. Water deeply and less often, one to two times a week when rain is short, rather than a little every day. Turn the system off during rainy stretches. A rain sensor is a simple, useful addition. This single change often makes the biggest difference, and it helps every other treatment work better.
Step 2: Fix the wet spots
If dollarweed is concentrated in one area, look at drainage. Extend downspouts away from the lawn, check for broken sprinkler heads, and look for low spots where water collects. Serious standing water may need regrading. Our article on yard grading and fixing standing water covers what that involves.
Step 3: Thicken the lawn
Mow at the correct height for your grass type so the turf shades the soil. Fertilize according to a soil test. A dense lawn crowds out dollarweed runners over time.
Step 4: Treat with a selective herbicide
Once the conditions are corrected, a selective postemergent herbicide finishes the job. Clemson lists several product types for use on warm season lawns. The right choice depends on your grass:
| Grass type | Notes from Clemson guidance |
|---|---|
| St. Augustine | Atrazine, imazaquin and some combination broadleaf products are options. Three way products (2,4-D, MCPP and dicamba) should only be used at the reduced rates the label lists for this grass. |
| Centipede | Similar options to St. Augustine. Centipede is sensitive to 2,4-D, so use reduced rates only where the label allows. |
| Zoysia and bermuda | Tolerate a wider range of broadleaf products. Check the label for your grass. |
Some newer products with multiple active ingredients are labeled for dollarweed across all the common warm season grasses. Whatever you use, read and follow the label for your specific turf. The label is the law, and it lists the rate, the interval between applications and the grasses it is safe on.
Step 5: Time it right
Clemson recommends treating dollarweed in late spring, after the lawn has fully greened up, while the weeds are still small. Fall is also a good window for some products. Avoid these situations:
- During spring green up, when centipede and St. Augustine are easily injured
- When air temperatures are above 90 degrees
- When the lawn is drought stressed
- Right before rain or right before mowing
Expect to need more than one application. Dollarweed runners are persistent, and follow up treatments spaced according to the label are normal.
Dollarweed in flower beds
Dollarweed also creeps into landscape beds. Hand digging works if you get the runners. A layer of mulch or pine straw about three inches deep helps block new growth. For spot treatment in beds, a nonselective product can be used carefully, but it will injure any plant it touches, so shield your shrubs and never let it drift onto the lawn.
How Right Stuff handles dollarweed
When our crews see dollarweed on a property, we look at irrigation settings and drainage first, because treatment without that step tends to fail. Then we build targeted treatments into the regular weed control schedule at the right times of year. Adjusting mowing height for your grass type is part of the plan too.
Frequently asked questions
Does dollarweed mean my lawn is overwatered?
Very often, yes. Dollarweed is a strong sign that the soil is staying wet too long, either from irrigation or poor drainage. Cutting back watering frequency is the first thing Clemson recommends.
Can I pull dollarweed by hand?
You can pull small patches, but it is hard to get all the underground runners, and pieces left behind will regrow. Hand pulling works best in beds or for a few scattered plants. In a lawn, combining better watering with a selective herbicide is more effective.
Is it safe to spray dollarweed in St. Augustine grass?
Yes, if you choose a product labeled for St. Augustine and follow the label rate. Avoid spraying during spring green up or when temperatures are above 90 degrees. St. Augustine is more sensitive than zoysia or bermuda, so the label details matter.
How long does it take to get rid of dollarweed?
Expect a full season or more. The first treatment knocks it back, but runners and seeds usually need follow up applications. Lasting results come from fixing moisture and thickening the lawn so dollarweed has nowhere to return.