Learn to Keep Dollarweed Away

Dollarweed, sometimes called pennywort, is a water-loving perennial weed that can spread quickly in damp grassy areas or survive floating in water. Learn how to keep dollarweed out of your lawn by reading more below.

Keeping your lawn healthy and strong to avoid giving room to invasive weeds and other unwanted growth is a key part of dollarweed prevention. Our recommended lawn maintenance schedules can help you keep your lawn lush and strong. Consider these practices along the way:

• Mow Properly. It is best to maintain a uniform height across your turf, and to avoid cutting the grass too low at any time. Set your mower to cut the top 1/3 of the grass blades per mow. This practice will allow for stronger grass growth and better weed prevention.
• Irrigate if Necessary. Consult your local extension office for details on your turf's water requirements and develop an irrigation schedule based on that information.
• Fertilize as Needed. If a regularly performed soil test indicates that amendments could help your lawn grow stronger, select a fertilizer labeled for your warm or cool season turf and apply according to labeled instructions. Avoid over-fertilization.
• Aerate Annually. Dollarweed loves water, so avoiding compacted, saturated soil is a good practice for dollarweed prevention. Proper aeration can reduce moisture levels and make a grassy area less hospitable to this and other water-loving weeds.

Pre-emergent herbicides work to stop new weeds from germinating in the soil. If applied as directed at the right time of year, these products can be your best defense against future dollarweed growth on your property.

Select a pre-emergent herbicide that is labeled for use on your turf type and for dollarweed prevention. Dollarweed is also known as Pennywort, and may be listed under that name on some product labels. Check for both names when confirming product compatability.

While wearing the appropriate PPE, mix the dollarweed preventer with water in a hand-pump sprayer or backpack sprayer, or fill a wheeled granular spreader with a granular product. Consult the product label for usage rates and application recommendations. Apply to your lawn evenly and follow any post-application instructions regarding watering or mowing. Further applications may be necessary. Consult the product label for additional details.

It is most effective to apply a pre-emergent herbicide in the early spring. Do so after the last frost of winter but before weeds begin to germinate. A fall application can also be made after the first frost of the fall but before the ground freezes for the winter.