Common Ragweed

Ambrosia artemisiifolia

Common Ragweed is a summer annual broadleaf weed that is also referred to as Wild Tansy, Hog-weed, Bitterweed, Mayweed, Hay-fever Weed, Blackweed, Roman Wormweed and Annual Ragweed. The pollen from this broadleaf weed is a primary cause of hay fever.

Identify

Alternate

Upright

Pinnate

Lobed

Pinnatifid

Common Ragweed can be identified by its vertical-growing, branching growth habit. However, the deeply pinnated leaves are perhaps its most identifiable feature, growing mostly alternate, though sometimes lower leaves are opposite. The leaves are often hairy, though sometimes smooth. This broadleaf weed has a shallow, fibrous root system. Common Ragweed produces small flowers that turn from green to yellowish-brown in color as they mature. Reproduction occurs by seeds.

Life Cycle

This broadleaf weed is often found growing in unkept lawns, gardens, crop fields, abandoned fields, vacant lots and areas along fence rows, roadsides and railroads. Common Ragweed can be found throughout much of North America.

Control

Ambrosia artemisiifolia can be difficult to remove when relying solely on cultural weed control methods, such as good mowing and watering practices. The root system of this broadleaf weed is shallow enough that physical removal is possible. However, the numerous seeds that are produced can remain viable in the soil for as many as five years.