Hardiness zones
Sunset 11-13
USDA 9-10 (arid zones only)

Landscape Use: Xeric landscape plantings as a low growing and spreading filler plant, native lower Sonoran Desert habitat restoration projects including desert slope stabilization, mass plantings, highway medium plantings

Form & Character: Evergreen herbaceous perennial, mounding, rounded, regular.

Growth Habit: Winter active, summer dormant, moderate to 2" long (1" in it's native habitat) with slightly lesser spread, irrigation will increase size.

Foliage/Texture: Leaves are alternately arranged, simple, evergreen, distinctly triangular or with a wedge-shaped base, gray-green, occasionally revolute to 3" long, but generally smaller; medium fine texture.

Flowers & Fruits: Terminal clusters of small yellow-green flowers in December to April. Fruit pea sized with hooked spine, inconspicuous.

Seasonal Color: More heavily vegetated in winter. Otherwise no accent.

Temperature: Tolerant to 22^oF

Light: Full sun

Soil: Well drained soils are required. Slopes, with rocky dry soils are best

Watering: None needed after establishment. Occasional water during the winter may be applied if winter rains fail to materialize in order to invigorate. Responds well to supplemental water especially during the summer; however, too much extra water will encourage rank growth.

Pruning: Slight shearing during the fall before onset of winter growth is used to increase landscape symmetry.

Propagation: Seed

Disease and pests: Root rot in poorly drained soils is common.

Additional comments: A. deltiodea is generally without outstanding floral accent features and is not a plant for use in mesic garden themes. It is best as a companion filler plant for native desert restoration projects and plantings away from people. Triangle bursage is the principal nurse plant for saguaro at Organ Pipe National Monument. Its shade reduces maximum soil surface temperatures, and it also provides a microhabitat with elevated soil nitrogen levels.

Allergy alert: Recently many landscape architects have taken to specifying Ambrosia in native landscape planting designs. However, Ambrosia plants including A. deltoidea plants have foliage that is allergenic causing an acute airborne contact dermatitis for many people.