How to Grow Sunflower
Annual
Sunflowers (Helianthus annuus) are cheerful, fast-growing annuals prized for their big daisy-like blooms that track the sun as young plants. US gardeners grow them for dramatic height and color, as a magnet for bees and songbirds, and for edible seeds and long-lasting cut flowers. They are easy to start from seed, making them a favorite for beginners and children.
Planting
Sow sunflower seeds directly in the garden after the last spring frost, once the soil has warmed to about 55 to 60 degrees F. Choose a spot in full sun with at least 6 to 8 hours of direct light and loose, well-drained soil; sunflowers tolerate a wide range of soils but resent soggy ground. Plant seeds about 1 inch deep, spacing large single-stem types 12 to 18 inches apart and branching or giant varieties 18 to 24 inches apart to allow airflow. For a steady supply of blooms, make a fresh sowing every 2 to 3 weeks until about two months before your first fall frost.
Care
Water young plants regularly to keep the soil evenly moist while roots establish, then water deeply but less often, aiming for about 1 inch per week during dry spells. Sunflowers are light feeders, so rich or heavily amended soil usually supplies enough nutrients; overly lush conditions can produce weak stems. Tall and top-heavy varieties benefit from staking, especially in windy or exposed sites, so set a sturdy support early and tie the stalk loosely. If you want continuous branching bloom rather than seeds, snip spent flowers; at season's end simply pull the plants after they fade or leave seed heads standing for birds.
Bloom time
Sunflowers typically bloom from midsummer into early fall, usually 55 to 100 days after sowing depending on the variety. Single-stem types produce one flush, while branching types keep opening new flowers over several weeks.
Garden uses
Sunflowers make excellent cut flowers and are outstanding for pollinators, drawing bees and butterflies all summer while their ripe seeds feed finches and other birds. Use giants as a back-of-border screen or living fence, and grow dwarf varieties in containers or along walkways.
Tips
Protect newly planted seeds and seedlings from birds and squirrels with netting or row cover until plants are a few inches tall. Choose pollen-free varieties if you want tidy indoor arrangements, and pick branching types for the longest cutting season. To harvest seeds, let the flower heads dry on the stalk until the backs turn brown, then cut and finish drying them in a well-ventilated spot.
General guidance for US gardens. Timing and hardiness vary by region; check your local frost dates and hardiness zone. Page updated Aug 4, 2026.