Annual
Narrowleaf / Mexican Zinnia
Zinnia angustifolia · Asteraceae
Also called: Narrowleaf zinnia, Mexican zinnia, Classic zinnia, Zinnia linearis (synonym)
Narrowleaf / Mexican Zinnia (Zinnia angustifolia) is a low-water annual well suited to Tucson and the low desert. It's a fast-growing annual.
Narrowleaf / Mexican Zinnia at a glance
- Water use
- Low (established)
- Sun
- Full sun, including reflected light, western exposures, and hot western walls - exceptionally heat-tolerant.
- Mature size
- 8-16 in tall, spreading 12-24 in wide (low, mounding/spreading habit)
- Growth rate
- Fast
- Bloom
- Golden orange, yellow, and white daisy-like flowers (and bicolors in hybrids like 'Profusion' and 'Star' series), Late spring through fall (May to frost); one of the best low-water annuals for sustained summer color in Tucson.
- Cold hardiness
- Frost-tender; killed by frost. Outstanding heat and drought tolerance for the low desert; far more durable in summer than Z. elegans.
- Soil
- Well-drained soil; tolerant of poor, alkaline desert soils. Amend with a little compost.
- Native range
- Northern Mexico and the southwestern U.S. borderlands; not native to the Sonoran Desert proper. Grown as a warm-season annual in Tucson.
- Best used as
- Low-water summer color, Groundcover-like bedding and borders, Reflected-heat and western-exposure spots, Containers and hanging baskets, Pollinator gardens
- Wildlife
- Excellent butterfly and bee nectar plant; attracts pollinators all summer.
- Toxicity
- Non-toxic to pets and people (Zinnia genus is ASPCA non-toxic) - safe around dogs, cats, and children.
How to grow Narrowleaf / Mexican Zinnia in Tucson & the low desert
Watering
Plant after frost danger, April through summer (handles monsoon planting well). Water deeply 1-2 times per week once established; quite drought-tolerant and far more forgiving of dry spells than common zinnia. Highly resistant to powdery mildew, so overhead irrigation is less of a problem.
Fertilizer & nutrients
Light feeder. Compost at planting is usually sufficient; a light application of balanced or slow-release fertilizer once or twice in the season keeps it blooming. Avoid heavy nitrogen.
Pruning & care
Essentially self-cleaning and mounding; little deadheading needed. Shear lightly mid-season if it sprawls or to refresh bloom.
Notes
A top-tier warm-season accent annual for all of Arizona - remarkably heat- and drought-tolerant, mildew-resistant, and tolerant of reflected light and western exposures where other annuals fail. The interspecific 'Profusion' and 'Zahara' hybrids (Z. angustifolia x Z. elegans) carry this toughness with a wider color range.
Sources: University of Arizona Cooperative Extension - Pima County Gardening Guides; Arizona State University horticulture plant database (Z. angustifolia / Z. haageana); AMWUA / Arizona low-water annual references