Mammoth Sunflower

Helianthus annuus Mammoth, Asteraceae

Zones

2–11

Lifespan

Annual

Growth

Fast

Growing Conditions

Full Sun (optimal)

Moderate

6 – 7.5

Drought

Frost

Heat

Pest Resistance

Disease Resist.

Two large sunflower varieties compete intensely for water, nutrients, and light when planted close together

Sunflowers produce allelopathic compounds that can inhibit smaller composites like coreopsis

Tropical palm and large sunflower compete intensely for light when grown together

Mammoth Sunflower grows in USDA hardiness zones 2 through 11.

Design guilds with Mammoth Sunflower and see companion relationships visually.