Common Sunflower
Helianthus annuus
An upright annual herb with coarse, hairy stems, broad heart-shaped to triangular leaves with toothed margins, and a single prominent terminal flower head.
- Light
- Full sun, requiring 6 to 8 hours of direct sunlight daily
- Water
- Moderate watering frequency, allowing the surface soil to dry slightly between waterings. Mature plants exhibit moderate drought tolerance.
- Growth
- Fast-growing herbaceous annual with a single upright stem, reaching mature heights of 3 to 10 feet or more depending on the variety, with a spread of 1 to 3 feet
Care instructions
Provide full sun exposure of at least 6 to 8 hours daily. Water regularly at the base to keep the soil moderately moist, allowing the top inch to dry out between waterings. Plant in well-draining soil and apply a balanced, low-nitrogen fertilizer sparingly during the growing season.
Growing details
Sunlight
Full sun, requiring 6 to 8 hours of direct sunlight daily
Watering
Moderate watering frequency, allowing the surface soil to dry slightly between waterings. Mature plants exhibit moderate drought tolerance.
Soil
Prefers well-draining loam or sandy soil with a neutral pH range between 6.0 and 7.5
Hardiness zone
USDA hardiness zones 2 through 11 cultivated as an annual
Growth habit
Fast-growing herbaceous annual with a single upright stem, reaching mature heights of 3 to 10 feet or more depending on the variety, with a spread of 1 to 3 feet
Bloom season
Mid-summer to early autumn, featuring large composite flower heads with bright yellow ray florets surrounding dark center disk florets
Propagation
Propagated easily from seeds sown directly into the soil after the last spring frost, spaced approximately 6 to 12 inches apart
Common pests & issues
Susceptible to powdery mildew, rust, stem rot, and fungal leaf spots, which can be prevented by ensuring good air circulation and avoiding overhead watering. Common insect pests include aphids and beetles.
Similar species
Jerusalem Artichoke (Helianthus tuberosus), which features similar rough leaves and yellow flowers but produces underground tubers and often has multiple branching stems.