Sunflower
Helianthus annuus
Sunflowers are bold, cheerful annuals that bring instant drama to any UK garden. Growing from seed to towering heights of 3 metres or more in a single season, their large golden flower heads track the sun and can measure over 30 cm across. Native to North America, they are one of the easiest flowers for children to grow. The seeds provide vital autumn food for finches and other garden birds.
How to grow sunflower
Sow seed directly outdoors from late April to May, once the soil has warmed to at least 10 degrees Celsius. Plant seeds 2 cm deep and 45 cm apart in the sunniest spot available. Sunflowers are not fussy about soil but perform best in fertile, well-drained ground. Water regularly, especially during dry spells — tall varieties need a lot of moisture. Feed fortnightly with a balanced liquid fertiliser once buds appear. Stake tall varieties from an early stage, as mature plants are top-heavy and vulnerable to wind. For cut flowers, choose branching varieties such as Velvet Queen or Valentine. Dwarf varieties like Teddy Bear and Little Becka work well in containers. Leave spent flower heads on the plant in autumn for birds to feed on the seeds. Sunflowers do not transplant well, so always sow where they are to grow.
Pruning
No pruning required. Remove side shoots on single-stemmed varieties if growing for the largest possible flower head. Leave spent heads for birds in autumn.
Propagation
- Seed (sow directly April-May)
Common problems
- Slugs and snails on seedlings
- Grey squirrels eating seeds
- Downy mildew
- Sclerotinia stem rot
- Wind damage to tall stems
Good companions
Related guides
How to Grow Sunflowers in the UK
Complete guide to growing sunflowers in UK gardens. Covers sowing times, best varieties, container growing, pests, and seed harvesting.
When to Plant Sunflowers in the UK
Exact timing for sowing sunflowers indoors and outdoors across UK regions. Covers giant, dwarf, and multi-headed varieties with planting calendars.
Flower Planting Calendar: Month by Month
Month-by-month flower planting calendar for UK gardens. Covers sowing times for annuals, perennials, biennials, and bulbs across all regions.