Santa Fe Botanical Garden

Common name: prairie zinnia

Family: Asteraceae (Aster)

Distribution: Western United States, Northern Mexico

Habitat: Mesas, slopes

Hardiness: USDA Zone 4 (-30 to -20 °F)

Life form: Deciduous perennial

Occurrence in New Mexico: New Mexico native plant

Growing Conditions: Zinnia grandiflora is native to the southwestern and south-central United States, from Kansas west to Nevada, and south to Arizona, New Mexico, Texas and northern Mexico, growing on dry, calcareous slopes and mesas at elevations from 2,000-6,000 feet. It grows in full sun or part shade. Plants will tolerate a variety of soils, including sand, sandy loam, gravelly, limestone or caliche-type soils. It will also grow in regular garden soil that is well drained. Plants should not be over-watered. Seed and plants are commercially available. Plants can be divided or propagated by woody cuttings in spring. Sow seeds in the garden in autumn or in spring when temperatures are 55-65°F. Germination rates are often low and cold-moist stratification may facilitate germination. Plants do not break dormancy until the heat of early summer warms the soil. Deadhead spent blossoms to prolong flowering. Individual plants are long-lived, and reseed readily. Prairie zinnias spread by rhizomes to form colonies, and are a good perennial groundcover for higher elevations. They are good for erosion control on steep, sandy slopes. This plant is ideal for dry, gravelly rock gardens, medians of roadways, edging and naturalized areas, as well as well-drained flower gardens.

Description: This low-growing prostrate or upright, mounded plant grows 4-8 inches high, and slowly spreads by rhizomes to form a groundcover. The stems are heavily branched and arise from a woody base. The oppositely paired leaves are linear, up to 1¼ inches long and less than ⅛ inch wide, with pointed tips and rough surfaces. Numerous papery yellow flowerheads, with 3-6 wide yellow rays and reddish-orange disk florets, cover the plant from mid-summer to frost.