Sunflower Growing Guide
Crop Rotation Group
Any sunny site with good drainage.
Sunflower seedlings often escape damage from light frost, but sunflowers are warm-natured plants with no tolerance of freezing temperatures.
Mix a light application of a balanced organic fertilizer into the soil prior to planting.
A rare "shelter" plant, sunflowers can be used to create shade for sun-stressed crops. Tall varieties can serve as trellises for transplanted runner beans seedlings (but not those grown from seed in the same area as sunflower seedlings are negatively allelopathic to competitors.)
Single Plants: 11" (30cm) each way (minimum)
Rows: 11" (30cm) with 11" (30cm) row gap (minimum)
Sow and Plant
Sow sunflowers from late spring to early summer. Where summers are long and warm, make a second sowing for autumn harvest. Poke seeds into the soil about 1 inch (3 cm) deep and 3 inches (8 cm) apart. Thin to 12 inches (30 cm) apart in all directions for dwarf varieties. Extremely tall sunflowers or those that grow into multi-branched bushes may require 3 feet (1 meter) between plants.
Our Garden Planner can produce a personalized calendar of when to sow, plant and harvest for your area.
Explore different sunflower varieties, which vary in size, color, growth habit, and the culinary quality of the seeds.
Cut sunflower heads when some of the seeds inside the edges appear ripe and fall away when rubbed, or when birds start harvesting them for you. Store in a warm, dry place.
Sunflowers will twist around to face the south or west, seeking the most abundant source of sun, which may be away from your garden.
Planting and Harvesting Calendar
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Pests which Affect Sunflower