Baccharis sarothroides
desert broom
Sonoran and Chihuahuan Deserts, southwestern North America
Overview
Baccharis sarothroides is an evergreen shrub 3-10 feet (0.9-3 m) tall and nearly as wide, forming a dense rounded to broom-shaped crown of slender green stems. The bright green to olive twigs are ribbed and photosynthetic and carry out most of the plant food production, while true leaves are sparse, linear, 0.2-0.6 inch (5-15 mm) long, and shed early in dry spells. Plants are dioecious, with male and female flowers on separate individuals. Small cream to pale yellow flower heads cluster at the stem tips in fall, after which female plants release masses of seeds tipped with white bristles that travel on the wind. A single shrub can shed tens of thousands of seeds, and the species colonizes roadsides, washes, vacant lots, and overgrazed range across the warm deserts. Deep roots reach stored moisture, so established plants stay green through drought, and crushed stems carry a turpentine-like resin scent. Growth is rapid, with seedlings reaching flowering size in two to three years. One trade-off is the heavy windborne seed, which spreads quickly into cultivated ground and disturbed soil.
Native Range
Native to the southwestern United States, including Arizona, southern California, New Mexico, and western Texas, and to northern Mexico including Sonora and Baja California. It grows along washes, roadsides, and disturbed desert flats from near sea level to about 5,500 feet (1,675 m).Suggested Uses
Used for erosion control on slopes and washes, as a fast screen on disturbed sites, and in revegetation of cleared desert ground. Male plants are used in landscapes to avoid the windborne seed of female individuals.How to Identify
Appearance
Size & Dimensions
Height3' - 10'
Width/Spread4' - 8'
Reaches mature size in approximately 3 years
Bloom Information
Flower heads open from September to December, peaking after late-summer monsoon rains. The heads are small, cream to pale yellow, and clustered at the branch tips. Female plants follow bloom with dense white bristle-bearing seeds that disperse on the wind through winter.
Detailed Descriptions
Flower Description
Cream to pale yellowFoliage Description
Bright green to olive stems with sparse green leavesGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grows in full sun on a wide range of soils, including sand, clay, caliche, and rocky fill, at pH 6.0-8.5. It tolerates drought, heat, and compacted ground, and established plants need no irrigation in zones 8-11. Excess summer water and shade produce weak open growth. Plants resprout from the base after cutting or fire. Seedlings establish quickly on bare disturbed soil, so volunteers appear wherever ground is cleared.Pruning
Plants cut back hard in late winter resprout densely from the base. Removing female plants before seed set limits windborne spread. Old unpruned shrubs grow woody and open at the base.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
winter