Dollar weed (Hydrocotyle spp.), also known as pennywort, is a persistent and invasive weed that can quickly take over lawns and gardens. Recognizable by its round, bright green leaves, which resemble small lily pads, dollar weed thrives in moist environments and can be a real challenge to eliminate. If left untreated, it can spread rapidly through both seeds and underground rhizomes. This guide will help you learn how to effectively get rid of dollar weeds, using both natural and chemical methods to restore your lawn or garden.
Why is Dollar Weed So Difficult to Control?
Dollar weed spreads through underground rhizomes and seeds, making it tough to control once it becomes established. It is particularly aggressive in areas with poor drainage or excess moisture, where the weed can rapidly multiply. Dollar weed can outcompete grass and other plants, as it easily adapts to both sunny and shaded areas, which is why it’s so important to address the problem as soon as you spot it.
Signs of Dollar Weed Infestation
Before tackling dollar weed, make sure to identify the plant correctly. Here are some distinguishing features:
- Round, lily pad-like leaves about the size of a silver dollar.
- Bright green foliage with a glossy finish.
- Leaves grow on long stems that emerge from underground rhizomes.
- Prefers moist, waterlogged areas but can grow in well-drained soil under the right conditions.
Non-Chemical Methods to Get Rid of Dollar Weed
If you want to avoid using chemicals, several natural methods can help control dollar weed. These methods may take longer to show results but are safer for your lawn, plants, and the environment.
1. Improve Drainage
Dollar weed thrives in areas with excess moisture. Addressing poor drainage in your lawn or garden is key to controlling its spread.
Steps to Improve Drainage:
- Aerate the soil: Use a garden fork or lawn aerator to break up compacted soil and improve water penetration.
- Fix low spots: If your lawn has dips or areas where water tends to pool, fill them in with soil to improve water flow.
- Adjust watering practices: Water your lawn deeply but infrequently. Too much water encourages dollar weed, so ensure your lawn dries out between waterings.
2. Hand Pulling
Hand pulling is effective for small infestations but requires diligence to ensure you remove the entire plant, including the root system.
How to Hand-Pull Dollar Weed:
- Moisten the soil: Water the area lightly before pulling, as this helps loosen the soil and makes it easier to pull the entire plant, including the roots.
- Grab near the base: Grasp the weed as close to the ground as possible and pull gently but firmly. Try to remove the entire root system to prevent regrowth.
- Dispose of the weeds: Bag and dispose of the pulled weeds properly—do not compost them, as any remaining rhizomes can resprout.
Repeat this process as needed, since it may take multiple sessions to fully control the infestation.
3. Mulching
Mulching is another non-chemical method that can help suppress dollar weed by blocking sunlight and preventing it from photosynthesizing.
How to Mulch Over Dollar Weed:
- Cut back the weeds: Mow or trim the dollar weed to ground level.
- Apply a thick layer of mulch: Cover the area with a 2-3 inch layer of organic mulch (like wood chips or bark) to block sunlight and discourage the weeds from growing back.
- Monitor for regrowth: Check the area regularly for any new shoots and remove them immediately.
4. Solarization
Solarization uses heat from the sun to kill dollar weed by raising the temperature of the soil to a level that destroys the weeds and their seeds.
How to Solarize:
- Mow the lawn: Cut the dollar weed and any surrounding vegetation down to ground level.
- Cover the area with plastic: Lay clear plastic sheeting over the area and seal the edges with soil or rocks to trap heat inside.
- Leave for 4-6 weeks: During the hottest part of the summer, leave the plastic in place for 4 to 6 weeks to effectively “cook” the weeds and their roots.
Solarization works best in sunny, hot climates, where the trapped heat can reach sufficient temperatures to kill the weeds.
Chemical Methods to Get Rid of Dollar Weed
For larger infestations or if natural methods are not providing results, chemical herbicides may be necessary. When using herbicides, it’s important to follow the manufacturer’s instructions carefully to avoid damaging your lawn or surrounding plants.
1. Selective Broadleaf Herbicides
Selective herbicides target broadleaf weeds like dollar weed without harming grass. These herbicides are particularly useful if dollar weed is invading your lawn.
How to Apply Broadleaf Herbicides:
- Choose the right product: Look for herbicides containing active ingredients like 2,4-D, dicamba, or triclopyr, which are effective against dollar weed.
- Apply during active growth: Apply the herbicide when the dollar weed is actively growing, usually in spring or early summer.
- Follow the instructions: Carefully follow the product label’s instructions for mixing and application. Spot-treat areas with heavy infestations to avoid overuse of chemicals.
- Monitor and reapply: You may need to reapply the herbicide after a few weeks, depending on the size of the infestation.
2. Glyphosate-Based Herbicides
Glyphosate is a non-selective herbicide that kills any plant it touches, including grass. This method is best used in areas where dollar weed has completely taken over, or in garden beds where grass is not a concern.
How to Use Glyphosate:
- Spot-treat the dollar weed: Use a paintbrush or a sprayer to apply glyphosate directly to the leaves of the dollar weed. Be careful to avoid desirable plants.
- Wait for results: It typically takes 1-2 weeks for the glyphosate to work, killing the weeds down to the roots.
- Reapply if needed: Some areas may need a second application if the weeds begin to regrow.
Preventing Dollar Weed Regrowth
Once you’ve successfully removed dollar weed from your lawn or garden, taking steps to prevent its return is crucial. Because dollar weed thrives in moist, nutrient-poor environments, the best prevention strategies involve maintaining a healthy lawn and proper drainage.
1. Lawn Maintenance
- Mow regularly: Keeping your grass at the recommended height helps prevent weeds from establishing. For most lawns, keep the grass around 2.5 to 3 inches tall to shade the soil and inhibit weed growth.
- Fertilize properly: Healthy grass outcompetes weeds, so make sure to fertilize your lawn with a balanced fertilizer. Avoid over-fertilizing, as excess nutrients can encourage weed growth.
- Water wisely: Water your lawn deeply but infrequently, allowing the soil to dry out between waterings. Dollar weed thrives in consistently moist environments, so reducing water can help prevent its return.
2. Improve Soil Conditions
- Aerate compacted soil: Compacted soil can lead to poor drainage, which promotes dollar weed growth. Aerate your lawn annually to loosen the soil and improve water penetration.
- Amend poorly draining soil: If your lawn or garden has heavy clay soil, consider adding organic matter like compost to improve drainage. Well-drained soil discourages dollar weed from spreading.
3. Regular Monitoring
Even after successfully removing dollar weed, regularly check your lawn and garden for any signs of regrowth. Spot-treat any new patches as soon as they appear to prevent a full-blown infestation.
Conclusion
Getting rid of dollar weed requires a combination of persistence and the right control methods. Whether you opt for non-chemical approaches like improving drainage, hand-pulling, and mulching, or turn to chemical herbicides for larger infestations, the key is to stay vigilant and consistent in your efforts. Once the weed is under control, taking preventative measures like proper lawn care and drainage improvement will help keep dollar weed from returning, allowing your lawn and garden to thrive.
FAQs
- How long does it take to get rid of dollar weed? Depending on the method used and the size of the infestation, it can take anywhere from a few weeks to several months to fully eliminate dollar weed. Chemical treatments may provide quicker results, but consistent effort is needed for long-term control.
- Can I pull out dollar weed by hand? Yes, hand-pulling can be effective for small infestations. However, be sure to remove the entire root system, as dollar weed can regrow from remaining roots or rhizomes.
- What is the best herbicide for dollar weed? Selective herbicides containing ingredients like 2,4-D, dicamba, or triclopyr are effective against dollar weed without harming grass. Glyphosate can also be used for spot treatment, but it will kill any plant it touches.
- Does dollar weed grow back after treatment? Dollar weed can regrow if the entire root system isn’t removed or if conditions remain favorable for its growth (e.g., excess moisture). Regular monitoring and follow-up treatments may be necessary to prevent regrowth.
- How can I prevent dollar weed from returning? Maintain a healthy lawn through proper mowing, fertilizing, and watering practices. Improve drainage in areas prone to excess moisture and regularly monitor your lawn for signs of weed regrowth.
- Does vinegar kill dollar weed? Vinegar can kill the above-ground parts of dollar weed, but it may not effectively kill the roots. It can be used as a temporary solution, but repeated treatments will likely be needed to fully control the weed.