Scientific Name: Ambrosia artemisiifolia
Also known as: Roman ragweed, Annual ragweed, Low ragweed, short ragweed, Small ragweed, Common ragweed
Erect 3.3 to 10 ft. (1-3 m) tall, taprooted late-summer annual with upright, branched stems forming a bushy rounded top, stems hairy early, becoming smooth. Leaves hairy, deeply twice dissected; opposite basally, alternate upward, appearing ragged. Foliage fragrant when crushed. Male and female flowers separate, green. Male flowers to tiny saucer-shaped heads. Flowers in spikelike racemes, erect to drooping, flowering late summer until frost. Pollen is common cause of hay fever. Giant Ragweed (A. trifida L.) is similar except larger. 3.3 to 20 ft. (1-6 m) tall, leaves opposite and three to five lobed instead of alternate and deeply twice dissected with Common Ragweed. Early inhabitant in disturbed fields, pastures, roadsides, and waste areas. Propagation: Seed.
Maintain a regular mowing schedule.
Postemergence control with repeat applications of two- or three-way mixtures of 2,4-D, Dicamba, MCPP or MCPA. Repeat applications of mixtures of 2,4-D, carfentrazone, dicamba, MCPP, MCPA, and/or sulfentrazone. Other postemergence options include triclopyr alone or combined with 2,4-D. Check the herbicide label for specific application rates and turfgrass tolerance before use.
Weed Photos: Courtesy of Dr. Lambert McCartey. Clemson University. Clemson, SC.