How to Grow Sunflower
Annual
Sunflowers are cheerful, fast-growing half-hardy annuals with bold golden blooms and handsome foliage. They range from compact plants for containers to towering varieties for a sunny boundary. Their flower heads are excellent for pollinating insects, and ripening seed heads can provide a welcome late-season feast for garden birds.
Planting
Sow one or two seeds per 9 cm pot indoors from April, at roughly 18 degrees C, and keep compost just moist. Plant out after the last spring frost, allowing 30 to 60 cm between plants according to the final height. You can sow directly outdoors from late April or May in warm, prepared soil, protecting seedlings from slugs. In northern gardens and Scotland, direct sowing is often safer from May onwards.
Care
Water deeply in dry weather, especially while plants are establishing and producing buds. Put in a sturdy cane or stake at planting time for tall varieties, securing stems loosely as they grow. A mulch of garden compost helps retain moisture. Remove faded flowers if you want tidier plants, but leave some heads to mature if birds are a priority.
Bloom time
Most sunflowers bloom from July to September, with early indoor sowings sometimes flowering in late June. Later sowings extend colour towards October, although cool weather and autumn gales can shorten the display.
Garden uses
Use tall sunflowers as a dramatic screen, at the rear of a border or as a focal point in a children's garden. Dwarf forms brighten patio pots. The large flowers are striking in arrangements, and single types are especially good for bees. Mature seed heads add seasonal interest and bird value.
Tips
Choose a sunny, sheltered position and protect young plants from slugs and snails. Sow a short row every 2 to 3 weeks until June for flowers over a longer period. Check seed packets for stated height, as spacing and staking needs differ greatly between dwarf and giant varieties.
Growing Sunflower: frequently asked questions
How do I grow sunflower in the UK?
Sow one or two seeds per 9 cm pot indoors from April, at roughly 18 degrees C, and keep compost just moist.
When does sunflower flower?
Most sunflowers bloom from July to September, with early indoor sowings sometimes flowering in late June.
How do I care for sunflower?
Water deeply in dry weather, especially while plants are establishing and producing buds.
General guidance for UK gardens. Timing and hardiness vary by region and season; the RHS or a local garden centre can advise for your area. Page updated 19 Sep 2026.