Having a weed-free lawn is no easy task. There are literally hundreds of weed varieties that are common in Georgia. While some broadleaf weeds are easy to identify and treat, this article looks at the five most common grassy weeds that may be hiding in your lawn, impostering your lovely St. Augustine, Zoysia, Bermuda or Centipede grass blades. Don’t be discouraged, lawn care professionals have the knowledge, experience and equipment to leave those weeds begging for mercy.
The University of Georgia has a tremendous amount of information on their Official Turfgrass Website. Many of the details and photos below were sourced there and you can learn even more about weed and pest management, water conservation and soil testing there.
Scientific Name: Poa annua
Description: Small tufted to clumped winter annual. Leaf blade, smooth on both surfaces, with two distinct, clear lines, one on each side of the midrib. Lead tip kneeled or boat-shaped. Ligule membranous. Light green to whitish spikelets that lack cottony hairs, are arranged on branches, one to two per node, in dense to open flower clusters.
Region: Found throughout the world.
There are many varieties of crabgrass which can be found in Georgia and throughout the world including:
Blanket Crabgrass – Digitaria serotina
Goosegrass (Crowfoot, Silver Crabgrass) – Eleusine indica
Large Crabgrass – Digitaria sanguinalis
Southern Crabgrass – Digitaria ciliaris
Smooth Crabgrass – Digitaria ischaemum
Tropical Crabgrass – Digitaria bicornis
Description: Mat-forming annual with creeping stolons. Depending on the variety, leaf sheaths and blades can be hairy or smooth. Finger-like branches. Visible membranous ligule at the base of leaf blade.
Reproduction: Seed or Seed and Stolon
Region: Most are found throughout the United States and some are present in Cuba, Canada, Central and South America and Europe.
Yellow Nutsedge (Yellow Nutgrass)
Scientific Name: Cyperus esculentus
Description: Rapidly spreading, perennial with three-ranks basal leaves. Leaves flat or slightly corrugated, usually as long or longer than flowering stem, with long attenuated tip. Seedhead yellowish-brown or straw colored, formed at end of triangular stem. Tubers round, lacking hairs and formed at ends of whitish rhizomes. Does not form chains of tubers. Tubers slightly sweet to taste.
Region: Found throughout the United States. Also found in Canada, the West Indies, mexico, Central and South America, Europe, Africa, Asia, and Hawaii.
Scientific Name: Cynodon dactylon
Description: The blades are a grey-green color and are short with rough edges. The stems are slightly flattened, often tinged purple in colour. The seed heads are produced in a cluster of two to six spikes together at the top of the stem. It has a deep root system. The grass creeps along the ground and roots wherever a node touches the ground, forming a dense mat.
Reproduction: Seeds, runners and rhizomes.
Region: Found throughout the United States and Western Canada.
Fall Panicum (Witchgrass)
Scientific Name: Panicum dichotomiflorum
Description: Sprawling to erect summer annual. Stems bent and branched outward. Leaf blade smooth, occasionally hairy on the upper surface, with a distinct broad, light green midrib. Ligule a fringe of hairs. Seedhead purplish colored at maturity, open and freely branched. Common during turfgrass establishment.
Region: Found from Maine, Michigan and Minnesota, south into Florida and west to Texas, Arizona, California and Hawaii. Also found in Europe.
The best way to treat grassy weeds in your grass is to prevent them from taking root in the first place by following basic lawn care recommendations. Weeds are less likely to thrive in lawns where grass is healthy, thick and deeply rooted. Watering, mowing and fertilizing your lawn properly lays the foundation and pre emergent treatments such as lawn spraying can limit the likelihood of weed infestations. If you already have a weed issue, post emergent treatments are also available. Contact your lawn care provider to discuss options for your specific situation.