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

Growing Zinnia grandiflora:
Rocky Mountain Zinnia

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Form: A subshrub with herbaceous stems on 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" high and 15" wide.
Flowers: Yellow, 3-6 rays, orange center, 1" wide.
Bloom: Summer to the end of fall.
Fruit: Thin, dry, seed capsule.
Leaves: Gray-green, narrow.
Stems: No thorns. Greenish, much-branched.
Roots: This plant slowly spreads by rhizomes and is considered non-invasive.
Wildlife: Attracts small butterflies, bees and birds. 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.
Water once established: Monthly. Too much water can harm the plant.
Soil: Well drained, dry, pH 5.6-8.5 (acidic to alkaline).
Prune: Remove dead plant debris when no more freezes are expected.
Litter: Low.
Propagation: Cuttings that include part of the woody base. The seed germination rate is low.
Uses: Ornamental, xeric garden, erosion control on sandy slopes,

This plant is a member of the Aster family (Asteraceae) and related to Zinnia acerosa. Other common names are Prairie Zinnia and Little Golden Zinnia.

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Zinnia grandiflora: Rocky Mountain Zinnia - flowers

Zinnia grandiflora: Rocky Mountain Zinnia

Latest update: February, 2019
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