Gardening information sheet - Ambrosia dumosa

1. *Burrobush/White bursage – Ambrosia dumosa (am-BRO-see-uh du-MO-suh)
Family: Asteraceae (Sunflower Family)
Native to: Southwestern deserts of N. America (Sonoran and Mojave Deserts) from CA to UT, AZ
and N. Mexico; common on arroyos, bajadas, gentle slopes, valley floors, and sand dunes at
elevations up to 3,000 feet in Creosote Bush Scrub, Joshua Tree Woodland communities.
Growth characteristics: part-woody sub-shrub mature height: 1-3 ft. mature width: 1-3 ft.
Rounded, compact sub-shrub with many slender, stiff branches. Leaves small, densely packed on
stems. Plant is drought deciduous. Entire plant covered in white hairs, giving silvery appearance.
Spreads by rhizomes, producing new plants. Individual plants live perhaps 50 years in wild.
Blooms/fruits: Blooms in Spring (Mar-May) but may bloom again in December (depending on
rains). Separate male and female flowers (same plant) in small, inconspicuous heads. Floral bracts
(leaves) turn an attractive purple. The bracts dry to form a spiny, sharp bur (protects seeds). Wind
pollinated – can cause nasal allergies.
Uses in the garden: Mostly used in desert-themed gardens. Very hardy and drought tolerant. Good
filler plant. Provides cover for smaller animals, birds.
Sensible substitute for: Non-native sub-shrubs.
Attracts: Provides cover and seeds for food.
Requirements:
Element Requirement
Sun Full sun.
Soil Well-drained soils – best on slopes; local pH (including alkali) are fine.
Water Low needs (supplement winter water in dry year); no/little summer water (Water
Zone 1-2)
Fertilizer None.
Other Inorganic or no mulch.
Management: Shear lightly in fall to shape. Don’t over-water; root-rot can be a problem.
Propagation: from seed: 1 month cold-moist pre-treatment by divisions: likely
Plant/seed sources (see list for source numbers): 10, 16, 47, 64 4/26/18
* California native, but not native to Western Los Angeles County © Project SOUND