Dollarweed

About

Dollarweed is a native, water-loving plant with round, shiny leaves like tiny lily pads that takes over soggy lawns in the South. It is mostly a sign of too much water, and cutting back irrigation is the first fix.

Also called pennywort, manyflower pennywort, manyflower marshpennywort

How to identify it

Look for

Leaves are round, glossy and scalloped, up to about the size of a silver dollar, with the stalk attached right in the center like an umbrella. Clusters of tiny white flowers rise on stalks, and white underground stems (rhizomes) connect the plants.

Look-alikes

Dichondra also has roundish leaves, but they are kidney-shaped with the stalk attached at the notch on the edge, not in the center.

Where it grows

Overwatered or poorly drained lawns, ditches, pond edges and low wet spots; it can even float in water.

When

It grows through the warm season and flowers from spring into fall.

How it spreads

White rhizomes, plus seeds and broken stem pieces.

Most common in

What to do, gentlest first

Start at the top. Weed killers are a last step; always read and follow the label.

1. Water less and improve drainage Prevent

   Water lawns deeply about once a week (1 to 1.5 inches) instead of a little every day, and fix soggy spots. Grass often takes back over once the soil dries out.

2. Pull it with its white runners By hand

   Hand-pull plants and follow the white rhizomes so you get them too; periodic pulling is often the most effective control.

   Complete eradication is rarely practical.

3. Mulch beds Barrier

   Keep about 3 inches of mulch in planting beds.

4. Vinegar only burns the tops Organic spray

   Horticultural vinegar may brown the leaves, but the rhizomes regrow.

   Strong vinegar (over about 11% acetic acid) can burn skin and eyes, so wear gloves and eye protection. It browns any leaves it touches, grass included.

5. Lawn herbicide matched to your grass Conventional spray

   In lawns, options include a 2,4-D/MCPP/dicamba mix, metsulfuron or imazaquin; the right choice depends on your grass type, so check the label.

   Metsulfuron, dicamba and atrazine can be taken up by the roots of nearby shrubs and flowers, and atrazine can reach groundwater. Read and follow the label. Many lawn weed killers also harm vegetables, flowers and shrubs, so don't let spray drift into beds, and keep dicamba products off the root zones of trees and shrubs.

Uses, wildlife and pets

For wildlife

UF/IFAS notes native pollinators visit its flowers and birds and waterfowl eat its leaves and seeds.

Pets

Not listed by the ASPCA.