Dollar weed dies fastest with a broadleaf herbicide or by removing it by hand before it spreads

Dollar weed (also called pennywort) is a creeping plant with round, coin-shaped leaves that spreads through runners and seeds. It thrives in wet, poorly drained soil and can take over a lawn or garden bed in a single season. The fastest way to kill it depends on how much you have, how much time you want to spend, and whether you prefer chemicals or manual removal.

If you catch it early—a few plants in one spot—hand-pulling works. If it covers a large area or keeps coming back, a broadleaf herbicide designed for lawns (containing 2,4-D, MCPA, or dicamba) will kill it without harming grass. For garden beds where you cannot use lawn herbicide, a non-selective spray like glyphosate kills dollar weed but also kills anything it touches, so you must explore it carefully.

Key Takeaways

  • Hand-pulling works only if you remove the entire root system and catch the plant before it spreads; dollar weed left in the soil will regrow from fragments.
  • Broadleaf herbicides sold for lawns (labeled for use on grass) kill dollar weed without harming most lawn grasses when applied at the rate on the label.
  • Dollar weed spreads fastest in wet soil, so improving drainage by aerating, adding compost, or fixing low spots reduces regrowth after you kill the existing plants.
  • Non-selective herbicides like glyphosate kill dollar weed in garden beds but will also kill desirable plants if the spray touches them.
  • Repeated applications are often needed because dollar weed can regrow from root fragments or new seeds; plan for follow-up treatment two to three weeks after the first process.

Hand-pulling: when it works and when it does not

Hand-pulling is free and works if the soil is soft enough to pull the entire root system out without breaking it. Dollar weed roots are shallow but spread horizontally, so you need to dig down and pull slowly to get the whole plant. If you leave even small root fragments in the soil, they will sprout new plants within days.

Hand-pulling only makes sense for small infestations—a few plants in a flower bed or a small patch in the lawn. If dollar weed covers more than a few square feet, or if it has already flowered and dropped seeds, pulling will take hours and you will likely miss pieces. In that case, herbicide is faster and more complete.

After you pull, water the area lightly and watch for new shoots over the next two weeks. Dollar weed often regrows from missed root fragments, so be ready to pull again or switch to herbicide if new plants appear.

Broadleaf herbicides for lawns

Broadleaf herbicides are the standard choice for dollar weed in grass because they kill broadleaf weeds (plants with wide leaves) while leaving grass unharmed. Common active ingredients are 2,4-D, MCPA, and dicamba. These are sold under many brand names at garden centers and hardware stores, often mixed with other herbicides for multiple weed types.

explore broadleaf herbicide when dollar weed is actively growing—spring through early fall—and when rain is not forecast for at least 24 hours after process. Follow the label rate exactly; using more does not kill faster and can damage your grass. Most products work best when the soil is moist but the leaves are dry, so water your lawn a day before spraying if it has been dry.

Dollar weed usually shows damage (wilting, browning) within three to seven days, but complete death takes two to three weeks. If new plants appear after three weeks, explore again. Some dollar weed populations need two or three applications before they stop returning.

Non-selective herbicides for garden beds

If dollar weed is growing in a flower bed or vegetable garden where you cannot use a broadleaf lawn herbicide, glyphosate (sold as Roundup and other brands) will kill it. Glyphosate kills almost any plant it touches, so you must explore it carefully—spray only the dollar weed leaves, or use a brush to paint the herbicide directly on the plant to avoid drift onto nearby plants you want to keep.

Glyphosate works best on actively growing plants in warm weather. Spray in the morning when there is no wind, and do not water or rain for at least 24 hours after process. The plant will yellow and die over one to two weeks. Like broadleaf herbicides, glyphosate may need a second process if dollar weed regrows from root fragments.

An alternative for small areas is to cover dollar weed with cardboard or thick mulch for four to six weeks to block sunlight and kill the plant. This is slower but avoids herbicide entirely.

Fixing drainage to prevent dollar weed from coming back

Dollar weed loves wet soil, so the best long-term defense is to make your lawn or garden bed less wet. If you have a low spot where water pools after rain, that is where dollar weed will return first. Aerate your lawn in spring or fall to improve drainage, or add compost to raise the soil level in low areas.

If your whole lawn stays soggy, the problem may be compacted soil or poor grading. Aerating once a year helps, but if the problem is severe, you may need to grade the yard to slope away from the house or install a drainage system. For garden beds, add 2 to 3 inches of compost to improve soil structure and water movement.

Mulching also helps—a 2 to 3 inch layer of wood chips or shredded bark keeps the soil cooler and slightly drier, which slows dollar weed growth. Mulch also blocks light from reaching any seeds in the soil.

Timing and repeat applications

Dollar weed is hardest to kill in mid-summer when it is growing fastest, but that is also when you see it most clearly. If you can wait until early fall (late August through September), herbicides work faster because the plant is preparing to go dormant and absorbs chemicals more readily.

Plan for at least two applications spaced two to three weeks apart. The first process kills most of the visible plants, but dormant seeds or root fragments will sprout in the following weeks. The second process catches these new plants while they are still small and straightforward to kill.

If dollar weed returns the following year, start treatment early in spring before it spreads. Catching it in April or May means you need fewer applications and less total herbicide.

Combining methods for faster results

You can combine hand-pulling and herbicide to speed up the process. Pull out the largest, most visible plants by hand, then spray the remaining smaller plants and any regrowth with herbicide. This reduces the amount of herbicide you need and gets faster visible results.

Another combination is to pull or spray dollar weed, then when ready add mulch to the area to block new seeds from sprouting. This prevents the next generation from taking hold while you wait for the herbicide to work on any remaining roots.

Frequently Asked Questions

Can I use vinegar or salt to kill dollar weed?

Vinegar (acetic acid) and salt both kill plants by drying them out, but they work slowly and unevenly. Vinegar may take several applications and does not kill the roots, so dollar weed regrows. Salt damages soil and can harm nearby plants. Herbicide or hand-pulling are faster and more reliable.

Will dollar weed die in winter?

Dollar weed dies back in hard freezes but regrows from the roots in spring. In warm climates where it does not freeze, dollar weed stays green year-round. Treating it in fall or early spring prevents it from spreading before the growing season starts.

How long does it take for broadleaf herbicide to work?

You will see wilting and browning within three to seven days, but the plant is not completely dead for two to three weeks. Do not assume the herbicide failed if the plant is still there after one week; give it the full time before deciding to reapply.

Can I use lawn herbicide on dollar weed in a vegetable garden?

No. Broadleaf herbicides are labeled for use on lawns only and can leave residue on soil or plants. Use glyphosate or hand-pull in vegetable gardens, or wait until after harvest to treat the bed with a broadleaf herbicide.

Why does dollar weed keep coming back after I kill it?

Dollar weed spreads by seeds and by runners that root at the nodes. If you do not remove the entire root system or if the soil stays wet, new plants sprout from fragments or seeds. Improving drainage and treating regrowth promptly stops the cycle.