Dollarweed and clover are common perennial weeds in lawns during the cool season. They can be difficult to control consistently, especially dollarweed, says LSU AgCenter turf specialist Ron Strahan.

“You need to know how to control them, but you also should know why these weeds are present in your lawn,” Strahan says.

Both dollarweed and clover are “indicator” weeds that suggest soil problems.

Dollarweed indicates that the soil is too moist, and this “too moist” location has reduced the competitive ability of the lawn. Correcting drainage problems can be difficult and expensive.

“Sometimes we can fix moisture issues by redirecting the water or adding a good top soil or sand to the location,” Strahan says. Unfortunately, there is not always a practical solution for drainage problems.

Clover is an indicator of low nitrogen fertility. “That is something you can address easily in early April when the lawn is actively growing,” Strahan says. “Fertilizing will not completely get rid of the clover problem, but it will make the lawn more competitive and less prone to clover infestations.”

Homeowners can control existing dollarweed and clover problems with herbicides.

Strahan says to consider using two different herbicides in the lawn — Trimec-type herbicides and atrazine herbicides at their labeled rates within two to three days of each other.

For example, you could spray the Trimec herbicide over a weekend and then follow up with atrazine a few days later. Using both the Trimec-type and atrazine herbicides on the same lawn will broaden the winter weed control spectrum and lead to more satisfying results than if either of these products were applied alone, Strahan says.

The Trimec herbicides kill weeds mainly through leaf uptake while the atrazine herbicides work mainly through root uptake.

“This two-pronged attack should clean up the dollarweed and clover as well as most other winter weed problems infesting your yard,” Strahan says.

Upcoming event

The annual Camellia Garden Stroll at the LSU AgCenter Hammond Research Station, 21549 Old Covington Highway, Hammond, will be held from 1 p.m. to 4 p.m. Sunday, Feb. 22. Visitors are invited to stroll through a collection of over 500 camellias, which were planted by Hody Wilson in the 1930s to early 1950s when he was the station superintendent.

The garden stroll is co-sponsored by the LSU AgCenter and the Tangipahoa Parish Master Gardener Association.

Got a gardening question? Write to GardenNews@agcenter.lsu.edu.