Garden Oracle / Drought and Heat Tolerant Gardening / Tucson - Phoenix - Arizona - California

Growing Zinnia grandiflora:
Rocky Mountain Zinnia

social icons Facebook Pinterest Instagram Threads Bluesky Reddit

Description
Form: A subshrub with herbaceous stems growing from a woody base.
Leaf retention: This plant dies to the ground in winter and grows back from its roots in the spring.
Growth rate: Moderate to rapid.
Mature Size: 12" (30cm) high and 15" (38cm) wide.
Flowers: Yellow rays surrounding a center disc of orange florets, 1" (2.5cm) wide.
Bloom: Summer to the end of fall.
Fruit: Each floret produces a dry, one-seeded fruit (cypsela), with attached hairs that allow wind dispersal.
Leaves: Gray-green, narrow.
Stems: Greenish, many-branched.
Roots: This plant spreads slowly by rhizomes and is considered non-invasive.
Wildlife: The flowers attract small butterflies, bees and birds. The foliage is avoided by rabbits and deer.
Toxic / Danger: No.
Origin: Southwestern United States and Mexico.

Cultivation and Uses
USDA hardiness zones: 4-9.
Heat tolerant: Yes.
Drought tolerant: Yes.
Sun: Full sun to part shade.
Soil: Well draining, dry, pH 5.6-8.5 (acidic to alkaline).
Water once established: Monthly. Too much water can harm the plant.
Prune: Remove dead plant debris when no more freezes are expected.
Litter: Low.
Propagation: Seed grown in pots. The seedlings can be carefully transplanted once they have 5-7 leaves
Uses: Ornamental, low water (xeriscape) garden, erosion control on sandy slopes.

Comments
This plant is a member of the Daisy family (Asteraceae) and related to Zinnia acerosa. Another common name is Desert Zinnia, also used for Zinnia acerosa.



Do you have additional information or a different experience for these plants that you would like to share? Email info@GardenOracle.com. All contributions are welcome and appreciated.

Zinnia grandiflora: Rocky Mountain Zinnia - flowers

Zinnia grandiflora: Rocky Mountain Zinnia

Latest update: October, 2024
© 2008-2025 by GardenOracle.com