Is it deer resistant?

Yes

Rough Sunflower is deer resistant.

Helianthus divaricatus

Deer: Rarely
Height: 6 ft (1.8 m)
Spread: 3 ft (91 cm)
Zones: 3–9
Light: Full sun

Perennial
Wildflower

Rough Sunflower (Helianthus divaricatus)

Photo: Shenandoah National Park from Virginia · Public domain

Also called Woodland Sunflower

Perennial Helianthus

More details

Light: Full sun, Partial shade
Water: Low, Medium
Type: Perennial, Wildflower
Maintenance: Low
Growth: Fast
Bloom: Summer
Foliage: Deciduous
Features: Drought tolerant, Flowering, Native
Best uses: Mass planting, Meadow, Naturalized, Woodland

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