Common Ragweed
Ambrosia artemisiifolia · Warm-season, Annual, C3/C4 intermediate (herbaceous weed)
Grass Family
Asteraceae (not a true grass, often mistaken for one due to its wind-pollinated nature and herbaceous appearance)
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Wild type
Hardiness Zones
USDA Hardiness Zones 3 through 9
About This Grass
An erect, branching summer annual plant growing 1 to 4 feet tall with deeply lobed, fern-like leaves and inconspicuous green flowers arranged in spike-like racemes that produce copious amounts of allergenic pollen.
Blade Characteristics
Leaves are opposite below and alternate above, deeply pinnately lobed, giving a lacy or fern-like appearance, hairy on both surfaces.
Root System
Deep, strong taproot allowing it to survive dry conditions and establish quickly in disturbed soil.
Growing Information
Origin Region
Native to North America, now widespread globally in temperate regions
Growth Habit
Upright, branching, taprooted annual herb
Sunlight & Water Needs
Requires full sun, moderate to low water needs, highly drought tolerant once established, thrives in disturbed soils with low fertility.
Mowing & Maintenance
Controlled by frequent mowing, pulling, or broadleaf herbicides; high maintenance when managing as a weed.
Special Characteristics
Produces prolific airborne pollen that is a primary trigger for hay fever and autumn allergies; highly adaptable and prolific seed producer.
Ecological Information
Native plant that acts as an aggressive pioneer species in disturbed soils, providing seeds for birds while frequently targeted for removal due to its high allergenicity.