Groundcover · Sonoran native
Prairie Zinnia
Zinnia grandiflora · Asteraceae
Also called: Plains Zinnia, Rocky Mountain Zinnia, Little Golden Zinnia, Desert Zinnia
Prairie Zinnia (Zinnia grandiflora) is a very low-water groundcover native to the Sonoran Desert region well suited to Tucson and the low desert. It thrives in full sun, with a slow to moderate growth rate.
Prairie Zinnia at a glance
- Water use
- Very Low (established)
- Sun
- Full sun; tolerates light part shade but flowers best and stays densest in full sun.
- Mature size
- 4-8 in H x 8-12 in W (slowly spreads by rhizomes into a wider mat)
- Growth rate
- Slow to moderate
- Bloom
- Bright golden-yellow ray flowers with an orange-red center disk, Late spring through fall (roughly May-October), with strong response to summer monsoon rains
- Cold hardiness
- Cold hardy to about -20 F (USDA Zone 4-5); also extremely heat and drought tolerant.
- Soil
- Needs good drainage; thrives in lean, rocky, gravelly, calcareous (alkaline) soils and dislikes rich or wet soil.
- Native range
- Southwestern U.S. and northern Mexico: Arizona, New Mexico, Colorado, Kansas, Oklahoma, Texas, south to Zacatecas
- Best used as
- Low rhizomatous groundcover and front-of-border, Rock and native gardens, Pollinator plantings, Parkways, medians, and hellstrips, Erosion control on dry sites
- Wildlife
- Attracts native bees, butterflies, moths, and other pollinators; deer resistant.
- Toxicity
- Non-toxic; no significant toxicity reported.
How to grow Prairie Zinnia in Tucson & the low desert
Watering
Very drought tolerant once established; water every 2-3 weeks in summer to extend bloom and little to none in winter when it goes dormant. Overwatering and poor drainage shorten its life.
Fertilizer & nutrients
None needed; this native performs best in poor, unamended soil and can become floppy with fertilizer.
Pruning & care
Cut back hard in late winter to remove dormant tan/brown stems and refresh the clump; light shearing after bloom flushes encourages reflowering.
Notes
A tough, very low-water Southwest native that forms a slowly spreading mound smothered in golden daisies, especially after monsoon rains. Excellent companion to Blackfoot Daisy for native low-water color in Tucson. Deciduous/dormant in winter (stems turn straw-colored), so plan for a cut-back in late winter. Sharp drainage and minimal water are key to longevity.
Sources: AMWUA 'Landscape Plants for the Arizona Desert'; Mountain States Wholesale Nursery; University of Arizona Cooperative Extension; Lady Bird Johnson Wildflower Center; Utah State University Western Native Plants