How to Get Rid of Dollarweed

The best way to get rid of dollarweed is to combine methods that kill or remove its roots and rhizomes with ways to reduce the soil moisture this weed loves so much. 

Hand-weeding, digging and systemic herbicides provide the best short-term results, but improving soil drainage and reducing watering is the only way for long-term control. We tell you all the popular options you can try to get rid of dollarweed and why some work better than others.

Are you sure it’s dollarweed?

The first step in effective weed control is knowing what you’re dealing with, and with dollarweed, location says a lot. Dollarweed, or pennywort, is a warm-season perennial that loves heat and moisture and is widely spread in the coastal regions of the United States. 

Hardy to USDA zones 5 to 10, it grows in the Grand Lakes region and along the coast, east and southeast, from Maine down through Florida and west to Texas. On the western coast, dollarweed is common in California and Oregon. 

All weeds need specific conditions to thrive and often signal problems in the soil or lawn care practices. Dollarweed grows in lawns with very wet soil, either from drainage problems or overwatering. 

You’ll find it in:

• Low spots that collect water
• Compacted areas where water puddles because it’s not properly absorbed
• Shaded areas near the house foundation or under dense trees
• Zones where your sprinkler system is overwatering

It also colonizes the edges of shallow bodies of water and can even live in the water with its leaves floating and the roots not touching the ground. If you have a pond, a water garden, or a lake in your yard, that’s where dollarweed seeds might be coming from.

Here’s what common dollarweed, Hydrocotyle vulgaris by its scientific name, looks like and how to identify it:

• Rounded leaves with wavy margins, looking like lily pads. Leaves grow parallel with the soil, supported by a stalk that meets the leaf in its center, making the mats of dollar weeds look like patches of tiny green umbrellas. 
• The leaves grow 1 inch (about the size of a penny) to 2 inches wide (about the size of a silver dollar), giving it its two popular names: dollarweed and pennywort.

When to scout for dollarweed? In warmer states such as Louisiana, Alabama, Florida, or Georgia, pennywort seeds germinate in early spring, in March and April. If you live in a cooler state, like North Carolina or Virginia, you’ll see this weed sprouting in late spring.

Dollarweed blooms small white flowers from June to August and dies off with the first frost of the autumn.

Make sure it’s dollarweed and not dichondra (ponyfoot). Many people confuse them. Although they look similar, dichondra has kidney-shaped leaves, and the stalks connect to the edge of the leaves, not in the middle.

How to control dollarweed without herbicides

Dollarweed is a water-loving plant related to aquatic species. It has very low resistance to drought. To get rid of this weed without chemicals, start by adjusting the moisture levels in your yard:

• Reduce watering. Turfgrass is more resilient to drought than dollarweed. Allow your grass to show signs of drought stress between irrigation sessions. 
• Improve soil drainage. This can range from simply core aerating compacted soil to installing a French drain or leveling your yard.
• Check the sprinkler system. Inspect it to ensure it uniformly applies the right amount of water across the lawn. Read more about the sprinkler system maintenance checklist and the cost of sprinkler repairs.
• Adjust the irrigation rate and frequency to account for the weather. Turfgrass needs 1 to 1.5 inches of water weekly, including rainfall. 

Another method to eliminate dollarweed naturally is hand-weeding, though it has limitations. Dollarweed spreads through seeds and rhizomes. The rhizomes are the bad news and the main problem — they grow underneath the soil and form nodes that give birth to new plants with roots. 

Each new plant sends out new rhizomes that make new plants, and so on. 

For hand-pulling to work, you must remove the weeds while small and dig out as much of the underground network as possible.

Mowing the weeds only provides limited control of pennywort. Kali Zammit and Rene Schmit from Louisiana State University explain why: “This is due to taller plants that are removed while plants below the mower blade escape untouched. The surviving plants then have the opportunity to continue multiplying.” 

Homemade weed killers to try on dollarweed

Consider a homemade weed killer if you don’t want to spread chemical herbicides on your lawn. Three of the most common options include:

• Vinegar. Mix 1 gallon of horticultural vinegar (20% to 30% acetic acid) with 1 tablespoon of liquid dish soap. Dollarweed has shiny, waxy leaves, and dish soap helps break the waxy layer. Soak the dollarweed leaves in this solution. 
• Baking soda. Lightly spray dollarweed with water, then spread baking soda over the leaves. Water helps the powder stick. 
• Boiling water. Pour boiling water over each weed carefully to avoid splashing the grass and other plants. 
• Rubbing alcohol. Mix 30 ml rubbing alcohol with 2 cups of water and 1 teaspoon of dishwashing soap. Spray it on pennywort leaves and protect desirable plants.

All homemade weed killers are contact herbicides, damaging only what they touch. They harm the foliage and hinder dollarweed growth and seeding. However, homemade herbicides rarely kill the entire plant, and dollarweed can regrow from its underground stems.

Best ready-to-use herbicides for dollarweed

Selective broadleaf weed killers are a good option if you’d rather use a commercial herbicide. 

The Golf Course Superintendents Association of America (GCSAA) recommends a mix of 2,4D, dicamba, and triclopyr with multiple applications. Atrazine and imazaquin are also effective options. 

When choosing a selective herbicide, check the label to see if it’s safe for your type of turfgrass. 

For example, atrazine can eliminate dollar weeds in St. Augustine and centipede lawns without harming the grass, but it’s not recommended for Bermudagrass. Atrazine also works as a pre-emergent; applied before dollarweed germinates, it can reduce the population by preventing seeds from sprouting.

On the other hand, trimec herbicides (a combination of 2,4-D, mecoprop, and dicamba) are safe for all warm-season grasses.

To be sure you apply the right herbicide and avoid damaging your lawn, contact the local Cooperative Extension Office for more information or hire a lawn care professional to apply the treatments.

If dollar weed has infested an area close to a body of water, look for herbicides that are safe for the aquatic environment. The Texas A&M AgriLife Extension includes on this list active ingredients such as:

• 2,4D
• Diquat
• Imazapyr
• Triclopyr

In lawn areas with more pennywort than turf, consider applying a non-selective herbicide such as glyphosate (Roundup). It kills all the plants, including grass, and clears the area so you can reseed the grass on weed-free soil. Glyphosate and imazaquin are also recommended to control dollarweed in landscape beds.

The best time to apply post-emergent herbicides: Spread post-emergent herbicides in late spring when pennyworts are actively growing, and temperatures are between 65 and 85 degrees Fahrenheit. 

“Treat warm-season lawns after the turfgrass is fully green. A newly seeded lawn should be mowed a minimum of three times before applying an herbicide.” specifies Millie Davenport, director of the Home and Garden Information Center at Clemson University.

Choose a day without rain or wind. Wear protective equipment and keep pets and kids away from the treated area for 24 to 48 hours.

Repeat the application after 12 to 14 days for good results.

Pro tip: Most herbicides work slowly, so you won’t be able to tell immediately if you missed a few lily pads here and there. Do your best to cover all the weeds. A few plants left untreated can regrow the colony.

How to prevent dollarweed in your lawn

Dollar weed is hard to remove once established, but you can control it if you maintain your lawn well. Here are the most important lawn care practices to keep:

• Water deeply and less often. Turfgrass responds by digging its roots deeper into the soil and gaining more drought tolerance. It grows denser, thicker, and more able to smother dollarweed.
• Mow the grass taller. Dollarweed invades where the turf is short, thin, and weak. Mow the grass taller to ensure stronger plants and a denser, deeper root system that hinders dollarweed root development.
• Rake fallen leaves and dethatch the lawn to improve evaporation. Dead leaves and a thick thatch layer keep the lawn damp and the turf thin and weak. 
• Core aerate the lawn to improve drainage and prevent water from dwelling on the topsoil.
• Trim back the trees to improve airflow and sun exposure in the shaded areas. Professional trimming costs $255 and $655, depending on how many trees you have in your yard and their size.
• Plant shade-tolerant turf under trees and shrubs to ensure dense growth, or cover the shaded soil with mulch to prevent dollarweed from sprouting.
• Check for puddles in your lawn and fix the cause. It can be a low spot you need to level, a broken sprinkler head, or a drainage problem.
• Check your watering schedule and adjust irrigation with rainfall to prevent overwatering. 
• Use the right amount of fertilizer for your turf type and fertilize only during the growing season. Overfertilization is another factor supporting dollarweed growth.

FAQ about controlling dollarweed

Is pennywort toxic to dogs?

According to the American Society for the Prevention of Cruelty to Animals (ASPCA), pennywort is not toxic to dogs or cats, but many others are. See a list of poisonous plants to keep your pet away from in our guide, “Most Poisonous Landscape Plants for Dogs”.

Does dollarweed die in winter?

Dollarweed is a perennial that can survive the winter. The foliage dies, but the roots remain viable in the soil and grow new plants come spring.

What are the benefits of dollarweed?

Dollarweed is a beautiful ornamental plant for ponds, rain gardens, and water gardens. It stabilizes the soil, improves water filtration and retention, and signals overwatering and drainage problems for lawn owners to fix.

It’s also a nutritious food for pollinators, birds, and animals. Though edible and medicinal, human consumption is discouraged due to dollarweed accumulating pesticides and other pollutants from the soil.

Leave dollarweed hunting to weed experts!

Controlling dollarweed in your lawn can be time-consuming and frustrating. If you spot their tiny umbrellas invading your turf, call the weed professionals. With Lawn Love, the weed control services are only a click away.

Save time and energy by hiring a pro and enjoy your thick, green, weed-free lawn without stress and headaches!

Main Image Credit: Krzysztof Ziarnek, Kenraiz | Wikimedia Commons | CC BY-SA 4.0