Common Sunflower
Helianthus annuus
An upright herbaceous annual with rough, hairy stems, broad, coarsely toothed, heart-shaped leaves, and large, bright yellow flowering heads.
- Light
- Full sun, requiring 6 to 8 hours of direct sunlight per day.
- Water
- Moderate water needs; allow soil to dry partially between waterings. Drought tolerant once established, but requires consistent moisture during early growth phases.
- Growth
- Upright annual with a fast growth rate, typically reaching mature heights of 3 to 10 feet or more depending on the cultivar, with a spread of 1 to 3 feet.
Care instructions
Provide full sun exposure for at least six to eight hours daily. Water deeply when the top inch of soil becomes dry, allowing excess to drain. Plant in well-draining soil and apply a balanced fertilizer during the growing season.
Growing details
Sunlight
Full sun, requiring 6 to 8 hours of direct sunlight per day.
Watering
Moderate water needs; allow soil to dry partially between waterings. Drought tolerant once established, but requires consistent moisture during early growth phases.
Soil
Well-draining loamy, sandy, or clay soils with a neutral pH range between 6.0 and 7.5.
Hardiness zone
USDA zones 2 to 11 when grown as an annual.
Growth habit
Upright annual with a fast growth rate, typically reaching mature heights of 3 to 10 feet or more depending on the cultivar, with a spread of 1 to 3 feet.
Bloom season
Mid-summer to early autumn, producing large yellow ray flowers surrounding a dark central disc.
Propagation
Propagated easily from seeds sown directly into the soil after the last spring frost.
Common pests & issues
Susceptible to powdery mildew, rust, stem rot, and aphids. Prevent by ensuring good air circulation and avoiding overhead watering.
Similar species
Jerusalem artichoke (Helianthus tuberosus), which has a more branched growth habit and tubers underground.