Overview
With stunning blooms from mid-summer to early fall, sunflowers bring summer vibes to the garden like no other plant. Flowers come in many colors (yellow, orange, maroon, and more) but they are commonly bright yellow with dark brown centers anywhere from 4 to 12 inches in diameter! These iconic blooms are a beautiful addition to any garden.
Sunflowers have two distinct growing habits, depending on the variety:
Single-stem varieties produce one flower for every seed, though blooms can reach up to 12 inches in diameter.
Branching varieties produce multiple smaller blooms per plant that branch off of the main stem.
Conditions
Sunflowers prefer fertile, well-draining soil that’s loose and deep. Ensure it is high in organic matter, as sunflowers feed heavily. Sunflower stems can grow tall, so ideally find a sheltered spot out of danger of heavy winds to limit the risk of weather damage. For optimal blooms and large plants, provide full sun (6+ hours of direct sunlight per day). Note - sunflowers may shade parts of the garden because they are so tall. Plant them in the northernmost section of the garden to prevent them from shading your other plants.
Planting
Plant sunflowers directly outdoors in the garden after all danger of last frost. Use our grow calendar tool to find specific planting dates for your region! Seeds germinate in 7-14 days.
Plant seeds ½" deep in groups of 3, and space the groups 12-24" apart, depending on the variety. Note - single stem varieties can be planted more closely together, around 6-12". Firm soil lightly, water and keep evenly moist. Thin to one seedling per group when seedlings have two sets of leaves.
Pests and Disease
Remove plants after they are killed by frost in fall to avoid disease issues the following year.
Harvest
Sunflowers can be left in the garden through blooming or cut for flower arrangements shortly after bloom. To harvest the seeds, cut the heads off after the stalks are quite dry and flower heads begin to turn yellow and droop. Cut flower-heads with a foot of the stalk attached. Hang heads in a warm, dry, well-ventilated place so the seeds may fully ripen and dry.