How To Control Dollarweed (Pennywort) in Your Lawn

dollar weed causes
Dollarweed thriving near a seaside outdoor faucet.

If you live in a warm or coastal climate, you’ve likely experienced the invasion of dollarweed (also called pennywort) in your lawn or garden. Dollarweed is caused by excess moisture, and it thrives in areas of poor drainage, excess irrigation, poor soil, and thin turf. Here’s what you need to know to control dollar weed in your yard.

About Dollarweed

Dollarweed has small, round, shiny leaves that are shaped like coins. It’s often mistaken for dichondra, a weed with similar round leaves, but the difference is in the stem. Dollarweed’s stem comes directly out of the center of the leaf, while dichondra’s stem is attached at the edge of the leaf. As weeds go, dollarweed’s glossy leaves are actually rather pretty, and if you can keep it under control, dollarweed can serve as a groundcover in impossible areas.

The main culprit in a dollarweed invasion of your lawn is too much water. Whether it’s caused by over-irrigating, too much rain, or poor soil drainage, thin turf in wet areas can quickly be taken over by this tough and hardy plant. Dollarweed spreads both by seeds and underground roots, making it very difficult to eliminate. Like many weeds, you may find that you’re managing dollarweed rather than eradicating it.

dollarweed

How To Control Dollarweed

If you have dollarweed in your yard, here are some tips on how to reclaim your turf:

  • Improve Grass: The presence of weeds is a sign that your grass isn’t healthy, and thick turf is by far your best defense. Take steps to identify why your grass is weak, and focus on getting your lawn healthy. Treat any diseases, insect infestations, soil problems, and maintain proper mowing height.
  • dollarweed

  • Reduce Irrigation: Use a rain gauge to make sure your lawn is receiving one inch of water per week. If it’s getting a lot more than that, reduce irrigation to keep your lawn from becoming soggy which can discourage your grass and encourage dollarweed.
  • Improve Drainage: Take steps to improve the drainage in your lawn to reduce the moist conditions that attract dollarweed. It may be as simple as aerating and top-dressing your lawn to improve the soil. Or it may require a more costly solution, such as an underground drainage system.
  • Remove Weeds: Hand pull dollarweed whenever you can, and be sure to get all the roots.
  • Herbicides: If all else fails, you may need to apply a broadleaf herbicide to help control dollarweed. Apply products while the weeds are actively growing. Choose an herbicide rated both for dollarweed and your grass type. Dollarweed is a common invader of warm-season lawns, which can be sensitive to generic herbicides. Some success with dollarweed has been reported with Atrizine (which requires professional application), Image (Imazaquin) and 2,4-D, although all of these products pose health hazards. You can also paint a full-spectrum herbicide (such as Roundup) directly on the leaves of dollarweed.
  • Organic Solutions: Natural, organic products, such as vinegar, may also work on dollarweed if repeatedly applied.

Further Information

14 COMMENTS

  1. Sir
    They told me the dollars weed are round, the Penny worth got a slit on top ,so they are not same. One are herb need to grow, one are weed need to kill.

  2. Dollarweed is an edible weed, much like parsley, the younger plants better tasting (like dandelion). Thus foraging in your yard will help eradicate this weed as well as offer a nice addition to your salads, much like Purslane (my all time fave).
    There are always better solutions than poisons!

  3. Hello Danny,

    I have read your article on the ‘control’ (nice weasel word) of Dollarweed (pennywort). I am confused.

    In the second paragraph you state that Dollarweed is characterized by the center attachment of the stem to the leaf, as opposed to the leaf’s EDGE as referenced a dichondra type plant. You make further distinction that these two types of plants are often confused with one another and in fact, (according to your article) are different. From an eradication point of view, is there a distinction between Dollarweed and a dichondra?

    I have a serious infestation of Centella asiatica (Goto Kola) http://en.wikipedia.org/wiki/Centella_asiatica in my yard. Your stem/attachment description of Dollarweed definitely precludes this infestation as being Dollarweed. Again, from a chemical eradication point of view, is there any difference in the treatment between these two kinds of plants?

    Thanks,

    Larry

  4. I paid $30,000 to have an all native garden planted in my .25 acre yard. The plants are beautiful but the gardner used bulk mulch and it was loaded with DollarWeed which has taken over the yard. I can use a rake to bring up the roots which are like chicken wire. Round up for Poison Ivy kills the leaf but does not affect the roots. I have pulled up wheel barrel loads of roots but their tiny filaments remain behind. My neighbor tells me I am wasting my time. I will try sugar and vinegar and covering the area with a weed control hardware cloth and putting mulch or gravel over it to hold it down. I am going to use Contractor weed control fabric. 300 square feet costs $128.00.

  5. I am also fighting dollar weed. I have tried most of the ideas mentioned here with limited success.I have tried Dudleys idea of laying weed mat that I purchased at Bunnings, but the weed managed to grow through it. So now I am really monitoring the water system and supplying my garden with as little as needed

  6. I have dollar weed in a like 50×50 foot area of my lawn. It is a low area which I’m going to level up with fill dirt. My yard is fenced because I have 3 dogs. Is there anything I can kill dollar weed with that won’t hurt my dogs?
    Thank you for your time.

  7. Nutgrass! Wretched stuff. Because the “nut” is the source of growth, the only way is to dig it up. They are attached by runners, so you can sort of follow the roots to dig up a patch. Sorry. Wish there was an easy way.

  8. My dollar weed is thriving in high ground in the sunniest and driest part of my flower bed.i find most of the info here to be either disprove or irrelevant to get this out of my FLOWER BEDS. Can you help or not. It sounds as if this weed will win no matter what from what I am seeing here. Not to mention that my problem is in the driest hottest and highest point in my landscape

    • Hi, Ken,
      Gardening questions can be tricky since the rules can change based on the region. You didn’t include the location, so we suggest ing your local Master Gardeners association.
      Master gardeners train on a range of topics so they can provide advice, at no charge, for people in their area.
      Thanks for your question, and good luck!

  9. My house is sitting on top of a swamp. I bought my house 11 years ago; I bought it new. There are at least 10-15 homes on my side of the street, all built on the same swamp at the same time. All the lots are built up. Now I have noticed the dollar weed really getting bad in my backyard. I am seeing several damp holes in my back yard as well. I am assuming the water table underground is causing the holes and creating a mess of dollar weed. I have tried the white vinegar and it works……..IF you spray everyday forever. The leaves of the plant do turn brown but the long tentacles of the dollar weed live on. It is a never ending battle. I guess I can just move but I love my community and will stay put. I guess the dollar weed will eventually take me, my house and my cats!

  10. I live in southern California ( hot dry summers 100 o F cool winters with some rain.. I have a lawn sprinkler system. I had a very large area ( 600sq ft ) of my lawn infested with dollar weed, which spreads underground by sending out shoots and a little nut develops with roots and from this the stem and leaf emerge. Untreated it smothers the grass and consumes water killing the grass. I have tried a multitude of commercial dollar weed killers ( but not Roundup, which migrates and will kill all garden plants). I have tried cutting the weed & grass very short and applying vinegar/lemon solution, letting the weed grow leaves and applying the vinegar mix..NONE of these work for the long term!!
    I have eradicated the weed by the following method.
    1) In the early spring dig out all the grass, weed roots and dispose in the dump.
    2) remove dirt and deeper roots down 3″ to 6″ depending on the root depth.
    3) cover the entire area with rolls of Heavy duty black plastic sheets,( 3′-4′) wide, overlapping the joints and holding down the seams and perimeter with broken bricks, rocks, piles of gravel so that NO LIGHT GETS IN!!!
    4)Turn off the sprinkler system if you have one.
    5) Leave plastic in place until FALL, to Cook any roots remaining.
    6) remove the plastic & dump it.. Apply mulch and then weed cloth then a mixture of good quality soil and sand at a rate of 3 to 1 and level this accurately and lightly roll to the correct depth ( top of pathways or patios less the thickness of sod. Choose an appropriate sod grass for your area. install sod per the vendor’s instructions. Fill all gaps/joints with Soil/sand mix. Water appropriately per local vendor’s directions. I prefer a grass that will spread to fill in any small voids..This method is hard work, time consuming and not cheep ( plastic and sod installers of sod.
    However, THIS METHOD WORKS for the long run..Nothing else does!!!

  11. Eradicating Dollar weed from flower beds.
    If you have dollar weed growing in your flower beds and up through the middle of plants ( eg. Iris, small bushes cactus) NONE of the chemical methods of permanent eradication works!!
    The only totally effective method is ;
    1) dig a trench 12″deep by 12″ + wide for temporary use.
    2) With care to not break the hair roots dig up each plant in your flower bed, wash off all the soil from the roots and carefully pullout ALL weed leaves, stems and roots, get all the tiny bits, then rinse again. place in trench cove lightly with mulch and water well.
    3) once all plants are removed in a manageable section, dig up the soil, put down a small tarp and place several shovels full into a 2′ x 2′ flat garden sieve 1′ grid , on a stand over the tarp. work the soil through the sieve with gloved hands. remove any root pieces and bin them.
    4) repeat this process several times until you have a 3′ high cone of soil, then shovel this pile through a fine flat garden sieve a shovel full at a time removing any more small pieces of roots. Bin them.
    5) Replant all plants from the trench and fill around them with the fine clean(no root) soil.
    6) cover the whole are with landscape cloth and carefully cut a second piece of cloth around each plant showing an absolute minimum of soil.
    7) cover the entire replanted are with 2’/3′ of mulch or compost.
    8) upon finishing each section, water well.
    9) don’t dig up more than you can sieve and replant in one day.
    WEEDS ERADICATED!!

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