Common Ragweed (Note: This is a broadleaf weed, not a grass)
Ambrosia artemisiifolia · Summer Annual, Broadleaf, C4 Metabolism
Grass Family
Asteraceae (Sunflower family); Subfamily Asteroideae. Not a member of Poaceae.
Grass Category
Invasive/Weed. Often found in Lawns, Pastures, and Disturbed areas.
Variety / Cultivar
None (Common Wild Species)
Hardiness Zones
USDA Zones 3-11. It is a summer annual that dies back after the first hard frost.
About This Grass
An upright broadleaf herbaceous plant reaching 1-3 feet. Fern-like, deeply lobed leaves with a soft, hairy texture. Greenish-yellow flower spikes appear in late summer.
Blade Characteristics
Leaves (not blades) are opposite at the base and alternate above, deeply pinnately lobed, lacy in appearance, 2-10 cm long, green with no ligule or auricles.
Root System
Shallow, fibrous taproot system. Does not form a sod; establishes quickly from seed in bare or thin turf areas.
Growing Information
Origin Region
Native to North America; naturalized and invasive globally, especially in Europe and Asia.
Growth Habit
Erect, branching, annual herb. Spreads via prolific seed production rather than rhizomes.
Sunlight & Water Needs
Full Sun preferred; adapts to most soil types including poor, dry, or sandy soils. Highly drought tolerant.
Mowing & Maintenance
Maintenance involves removal. Tolerates low mowing by developing a prostrate growth habit. Resistant to many common herbicides/mowing regimes once established.
Special Characteristics
Known for highly allergenic pollen. Extremely competitive for nutrients and water in turf and agricultural settings.
Ecological Information
Native to NA but considered a nuisance weed. Provides food for some specialized insects and birds (seeds), but generally managed as an invasive pest.