What Light Does a Sunflower Require?

Light

• All sunflowers, regardless of cultivar, require a full day of direct, uninterrupted sunlight (six to eight hours) to flourish. Sunflowers may tolerate partial or filtered shade, although they often fall over as they attempt to stretch toward the sun. Shorter varieties grown in partial shade can become sparse and leggy. Sunflowers are notable for the ability of the flower heads literally to shift and follow the sun as it moves across the sky.

Hardiness

• Sunflowers hail from North America, growing freely from central Canada through the United States into northern Mexico. They can be found in exposed, dry prairies, as well as cultivated fields and pastures. They can be grown as summer annuals virtually anywhere, although they perish as soon as frosts occur. The plant can be propagated by sowing seeds directly in a sunny spot in the garden. Young seedlings that are started indoors can be transplanted outdoors easily.

Culture

• Sunflowers are not terribly picky about soil, although they dislike acidic soil. Plant in a well draining, neutral to slightly alkaline soil, and fertilize with rotted manure or a balanced liquid fertilizer. Although somewhat drought-tolerant, sunflowers look their best when they are watered regularly and generously. Plants grown in full sunlight require more water than those grown in partial shade, because the soil dries out more quickly in full sunlight. Containerized plants also dry out more quickly.

Uses

• Sunflowers offer cover of wildlife, as well as food, for a wide variety of wild birds. Sunflower seeds can be used in bread and cereal, while the yellow petals can be used as a garnish in salads. To harvest seeds, cut the flower head off the stalk once the back of the flower head has turned completely brown and hang upside down over a brown paper bag. Scrape off seeds and enjoy. A net might be necessary to protect the flower head from hungry birds.