Direct sow Sunflower seeds outdoors where they are to grow from April to May. Choose a position in full sun on well drained soil which has been raked to a fine tilth. Sow seeds thinly, at a depth of 1cm (1/2") in drills spaced 45cm (18") apart and cover seed with its own depth of soil to exclude light. Water the ground regularly, especially during dry periods. Germination usually takes up to 21 days. When sunflower seedlings are large enough to handle, thin them out to 45cm (18") apart.
Alternatively, sow indoors in individual 7.5cm (3") pots from March to April at a temperature of 20-25C (68-77F). Once germinated, grow sunflower plants on in cooler conditions until large enough to plant outdoors after all risk of frost has passed.
Prefers a well drained soil in full sun. The ripe seeds make a tasty snack, while the fresh green flower buds can be harvested before they open and cooked in a butter sauce to create a tasty and unusual side dish.