Beach ragweed, Coastal ragweed
Ambrosia hispida
Asteraceae


Landscape Uses:

An accent groundcover in open coastal locations.

Ecological Restoration Notes:

Rather sporadic along the South Florida coast. Perhaps never common, but its numbers may have been reduced by coastal development and erosion.
Availability:
Grown by one or two native plant nurseries in South Florida. Available in Sanibel at the Sanibel Captiva Conservation Foundation (239-472-2329).
Description:
Small spreading herb.
Height:
Typically 1-3 feet in height but sometimes climbing into other vegetation. Spreading and forming large mats.
Growth Rate:
Moderate to fast.
Range:
Monroe County Keys and Miami-Dade County north along the coasts to Brevard and Lee counties; West Indies, southern Mexico and Central America. Rather rare and sporadic throughout its range in South Florida.
Habitats:
Beach dunes and coastal strand.
Soils:
Moist, well-drained sandy soils, without humus.
Nutritional Requirements:
Low; it grows in nutrient poor soils.
Salt Water Tolerance:
Low; does not tolerate long-term flooding by salt or brackish water.
Salt Wind Tolerance:
Secondary line; tolerates significant salt wind without injury, but usually is somewhat protected.
Drought Tolerance:
High; does not require any supplemental water once established.
Light Requirements:
Full sun.
Flower Color:
White.
Flower Characteristics:
Semi-showy.
Flowering Season:
All year; peak in summer.
Fruit:
Inconspicuous achene with 1-5 conic spines. All year.
Wildlife and Ecology:
The flowers are pollinated by wind.
Horticultural Notes:
Can be grown from cuttings. Newly planted patches may spread rapidly, then die back after 2-3 years.
Comments:
An excellent groundcover in coastal areas with high light.


Michelle Hayden
In habitat, Eleuthera, Bahamas, 2013
Roger L. Hammer