Timing is very important when it comes to controlling lawn weeds, especially some of the South’ s toughest invaders. Take action this spring and you’ll have a much better-looking lawn for the rest of the summer. And remember, maintaining a healthy, vigorous lawn – properly watered, fertilized and mowed (link to lawn care stories) - is one of the best ways to reduce weeds. As is understanding different types of herbicides. For more information on solving insect, disease and weed problems, go to the BioAdvanced Solution Center. Here are seven of the South’s toughest weeds (you will find more in the solution center):
With its blue-green leaves that form a compact, crab-like circle, crabgrass is one of the most recognizable lawn weeds. It’s an annual that often grows in bare or weak areas of a lawn. Improper watering and mowing too low makes it worse. Seed heads form in summer and fall and stretch upward, standing above foliage. As crabgrass matures leaves turn a purplish red color and the weed is harder to control.
To prevent Crabgrass, apply a pre-emergent herbicide in late winter to early spring. Application timing is very important. Check with your local Cooperative Extension System office for application timing for your region. If you have just a few plants, you can pull them by hand.
Aggressive, tough to control, broadleaf weed with creeping stems that root as they grow. Dark green, roundish leaves have scalloped edges. Purple flowers bloom in spring. Thrives in shady, overwatered lawns that aren’t properly fertilized. Will also grow in the sun. May need multiple herbicide applications to kill completely.
A spring mainstay forming a basal rosette of green, toothed leaves topped with sunny yellow flowers. A perennial weed, dandelions grow from a taproot, which can reach 2 to 3 feet deep. Puffballs spread seed far and wide. Thrives in thin lawns.
This aggressive, perennial weed is easy to recognize by its circular, bright green leaves that look like miniature lily pads with lobed edges. Small white flowers form in summer. Dollarweed loves moist, shady conditions but can take some sun. Difficult to control. May take repeat applications of appropriately labeled herbicide.
Recently becoming a more troublesome lawn weed in much of the South, Doveweed is an annual grass-like plant that resembles St. Augustinegrass, often making it hard to recognize until firmly established. A closer look reveals brighter green color than St. Augustinegrass and small blue to purple flowers. Spreads by stiff, horizontal runners that are difficult to mow. Thrives in moist, poorly drained soils. Seeds germinate in late spring. Properly timed pre-emergent herbicides effectively control Doveweed.
Nutsedge, also known as watergrass, looks like a grass but is actually a sedge. Sedges are easily distinguished from grasses by the triangular stems (hence the familiar phrase “sedges have edges”). Grasses have round stems. Nutsedges usually grow faster than most turf grasses, so you’ll often notice them rising above the lawn between mowings. You may also see the feather, umbrella-like flower clusters. Thrives in wet soils, so often seen in low spots in the lawn. Produces underground, bulb-like nutlets that are very persistent, making it a hard weed to control.
Classic three-leaf Clover with three bright-green leaves attached to one stem. Leaves have crescent-moon white marks. Small white flowers appear above leaves from spring to fall. Thrives in poor soils, lacking in nitrogen.