Sunflower

The sunflower is a large annual forb in the daisy family Asteraceae, native to North America and grown worldwide for its ornamental value, edible seeds, and oil. Varieties range from compact 40 cm container plants to towering 3-metre giants with seed heads up to 30 cm across. Flowers come in shades of gold, lemon, bronze, and deep burgundy, making them outstanding cut flowers as well as wildlife magnets for bees, butterflies, and birds. Sunflowers demand full sun and warm, well-drained soil; they are frost-tender annuals that do not survive Nordic winters.

Growing

Start seeds indoors 3–4 weeks before the last frost risk passes, sowing 1–2 cm deep in individual pots to minimise root disturbance. Alternatively, direct-sow into the garden once the soil has warmed to at least 10 °C, placing seeds 1–3 cm deep. Thin or transplant to a final spacing of 25–35 cm between plants and 30–60 cm between rows. Transplant outdoors only once nights stay reliably above 10 °C and all frost risk has passed. Choose the sunniest spot available; sunflowers tolerate light sandy to clay soils but need good drainage. Compact varieties suit containers of at least 20 cm diameter.

Care

Water deeply but infrequently, allowing the soil to dry slightly between waterings; established plants are drought-tolerant but reward consistent moisture during bud formation. Apply a balanced fertiliser once at transplanting, then switch to a low-nitrogen, higher-phosphorus feed to promote flowering rather than excessive leaf growth. Tall varieties (over 120 cm) may need staking in exposed positions — tie the main stem loosely to a cane before it reaches full height. Remove spent flowers on branching varieties to extend the bloom period. Mulch around the base to conserve moisture and suppress weeds.

Harvest

For cut flowers, harvest when the petals have just begun to open and the back of the disc is still firm and green. For edible seeds, wait until the back of the flower head turns yellow-brown and the seeds feel firm; bend or cut the head and hang it upside down in a dry, airy space to finish drying. Birds will signal readiness — cover heads with netting if you want to harvest before wildlife does. Compact single-stem varieties mature in 70–80 days; giant varieties can take up to 110 days from direct sowing.

In the kitchen

Roast dried sunflower seeds lightly in a dry pan, then season with salt for snacking. Press seeds for a mild, golden cooking oil suitable for frying and salad dressings. Use raw seeds as a topping for salads, granolas, and bread. Petals are edible and add colour to salads. Seed kernels can be blended into nut-free butter or stirred into baked goods for texture and protein.

Storing

Store dried whole seeds in an airtight container in a cool, dark place for up to 12 months. Hulled kernels keep for 3 months at room temperature or 6 months in the refrigerator. Freeze hulled seeds in a sealed bag for up to 1 year. Cut flowers last 7–12 days in a vase with fresh water changed every two days; recut stems at an angle each time.