Common ragweed (Ambrosia artemisiifolia) is a North American native plant in the aster family. It has a rapid growth rate and can reach four to six feet tall.
Common ragweed (Ambrosia artemisiifolia) plants.
Jackie Jordan, ©2023, Clemson Extension
Common ragweed is a summer annual. It can produce between 30,000 to 60,000 seeds per plant. Although, plants that grow in competition with other crops show a significant drop in seed production to around 3,000 seeds per plant. The seeds are high in crude fat and protein, making them an important food source for songbirds, game birds, and small mammals.
Common ragweed is a wind-pollinated plant, so male plants produce a large amount of pollen in the late summer and early fall, causing hay fever in some individuals. The plants can also cause a rash if handled without gloves.
Common ragweed grows in full sun and a wide range of soil conditions. It is usually found in open, disturbed sites. The seeds require a combination of light and the warmth of spring days, followed by cool nighttime temperatures, to germinate. A three-inch layer of mulch is the best defense in the landscape. For more information on mulch options, see HGIC 1604, Mulch.
Mowing regularly can help to limit common ragweed flower and seed production in lawns. Herbicides can be effective, but the best results are achieved when seedlings are under 6 inches in height. For herbicide recommendations, see HGIC 2326, Goldenrod and Ragweed.
