Dollarweed is a summer perennial weed better known as Pennywort.The Pennywort bears a small white flower with five petals on the end of a long stem where the flowers form in clusters. Pennywort grows along the Atlantic coastline from Maine to Florida and westward to Minnesota, Texas, Arizona, and California. This plant spreads by seed and underground rhizomes and tubers.
Pennywort (Hydrocotyle spp.) is a warm-season weed that prefers areas that stay wet. It gets the common name, dollarweed, from its silver- dollar-shaped leaves. The leaves look like miniature lily pads measuring 1-2” in diameter and are dark green with a glossy shine and scalloped edges.
Dollarweed is often confused with dichondra. One way to distinguish the two is by looking at the placement of the leaf stem. Dollarweed has a stem located in the center of the leaf while dichondra’s stem is located at the edge.
Dollarweed is considered a nuisance plant by many. The flower can float on top of water, making it a water-loving plant. The average landscape and lawn needs one inch of water each week for optimal health, according to Clemson Cooperative Extension. The University of Florida has completed research that shows dollarweed can be controlled by a reduction in irrigation. It is unrealistic to believe in total eradication of the dollarweed, but aggressive measures can be used to keep the plant under control. Mulching around trees, shrubs, and flower gardens with a substance that is several inches thick will help keep dollarweed from invading. Keeping the lawn mowed will also cut back on the destructive nature of Pennywort.
It may be necessary to use an herbicide if dollarweed has made its way into the landscape and invaded the lawn and flower beds. Hand-pulling the aggressive plants may also be an option if dollarweed is growing in places too risky for herbicide use. Follow all laws and restrictions concerning any herbicide use, as well as precautions and warnings.
This weed is not all bad, by any means. Every species has a place and a reason for existing on our great planet. Submerged portions of all aquatic plants provide habitats for many micro and macro invertebrates. These invertebrates are used as food by fish and other wildlife species. After aquatic plants die, their decomposition by bacteria and fungi provides food (called “detritus”) for many aquatic invertebrates. The seeds of pennywort are used occasionally as food by ducks.
It would not be practical or wise to attempt an eradication of all dollarweed. This plant is attractive in some settings and is necessary for the survival of some species. Pennywort would be attractive in a water feature such as a lily pond. To prevent overcrowding and to allow sunlight to penetrate the pond, some of the plants would necessarily need to be thinned by hand-pulling.
One man’s weed is another man’s treasure .If you do not mind the upkeep of pennywort, there is no reason to exclude it from your landscape in areas where it is a native plant. Transplanting pennywort to states or areas within states where the plant is considered invasive may cost you a heavy fine. It is best to keep with native plants indigenous to your particular area to maintain an ecological balance.
