Wildflower/Perennial · Sonoran native
Desert Four O'Clock
Mirabilis multiflora · Nyctaginaceae
Also called: Colorado Four O'Clock, Showy Four O'Clock, Wild Four O'Clock, Maravilla
Desert Four O'Clock (Mirabilis multiflora) is a low-water wildflower/perennial native to the Sonoran Desert region well suited to Tucson and the low desert. It thrives in full sun to part shade.
Desert Four O'Clock at a glance
- Water use
- Low (established)
- Sun
- Full sun to part shade; tolerates afternoon shade and reflected heat.
- Mature size
- 12-18 in H x 3-4 ft W (mounding, spreading herbaceous perennial)
- Growth rate
- Fast in the warm season; emerges in spring and spreads into a broad mound.
- Bloom
- Magenta to rose-purple trumpet-shaped flowers (1.5-2 in) borne in clusters., Late spring through fall (May-October), peaking with summer monsoon. Flowers open in late afternoon/evening and close by mid-morning.
- Cold hardiness
- Cold hardy to about -10 to 0 F (USDA zones 5-10); dies back to a large tuberous root in winter and is fully hardy in Tucson.
- Soil
- Well-drained sandy, gravelly, or rocky desert soils; tolerates poor and alkaline soils. Good drainage important.
- Native range
- Native to the southwestern U.S. including Arizona, and northern Mexico; occurs in the Sonoran Desert and adjacent uplands.
- Best used as
- Groundcover/sprawling accent, Perennial border, Mass planting, Pollinator and hummingbird garden, Under and between shrubs, Low-water xeriscape, Slope cover
- Wildlife
- Evening flowers are pollinated by hawkmoths (sphinx moths); also attract hummingbirds and native bees. Deer-resistant.
- Toxicity
- Considered toxic if ingested; roots and seeds contain compounds that can cause stomach upset. Keep in mind around pets and children, though it is rarely a significant hazard in the landscape.
How to grow Desert Four O'Clock in Tucson & the low desert
Watering
Drought tolerant once established via its large tuberous root; water deeply and infrequently. Occasional summer irrigation (every 1-2 weeks in peak heat) increases size and bloom; dies back and rests if water is withheld.
Fertilizer & nutrients
Low fertilizer needs; lean desert soils are adequate. A light spring feeding as growth resumes is optional but not required.
Pruning & care
No structural pruning needed; cut back dead top growth after frost or in late winter. It regrows from the perennial tuberous root each spring.
Notes
Herbaceous perennial that dies to the ground in winter and resprouts from a large woody tuberous root, spreading into a broad low mound up to 3-4 ft wide. Flowers open in late afternoon (hence 'four o'clock'). Vigorous warm-season spreader; gives a long, colorful magenta display with little water. Excellent native filler and groundcover for hot Tucson sites.
Sources: Arizona-Sonora Desert Museum; University of Arizona Cooperative Extension; AMWUA Landscape Plants for the Arizona Desert; Tohono Chul