Helianthus Annuus (Sunflower)

Helianthus Annuus flowers

Tall, fast-growing, hardy annuals, with very large showy flowers. A great favourite with children, who love to try and grow the tallest. For herbaceous perennial forms see Perennial Sunflowers.

Family: Asteraceae (daisy)
Botanical Name: Helianthus Annuus
Common Names: Common sunflower

Foliage: Deciduous, large, broad to oval, rough leaves.

Flowers: Very large showy flowers, available in a variety of forms and sizes, including singles and doubles. Available in varying shades of yellow, orange, red and cream, with a large dark central disk.

Flowering Period: Late summer to early autumn.

Soil: Moist but well-drained, moderately fertile soil (chalk, clay, sand or loam). Alkaline to neutral pH.

Conditions: Full sun is essential. Plant in a west or south facing aspect, in a sheltered position.

Habit: Tall, upright.

Type: Hardy Annual.

Origin: America

Hardiness: Hardy throughout the UK (usually dies after flowering at the end of the season).

Planting and Growing Helianthus Annuus

Thrives in any well-drained humus rich garden soil. Dislikes wet cold soils.

Plant separately or in small clumps in mixed beds. Tall varieties are best grown at the back of a border or as specimen plants. Lower-growing cultivars are more suited to the mixed border.

All forms are generally good as cut flowers.

Taking Care of Helianthus Annuus

Support tall varieties with strong canes or stakes. Protect from strong winds.

Water well in dry periods. For best growth feed the plants weekly with liquid fertilizer suitable for flowering plants.

Pruning

Remove dead flower heads to prevent self-seeding. Leave ripe heads on the bird table for birds to enjoy.

Pests and Diseases

Protect against slugs and snails. The leaves can be affected by grey mould.

Propagating Helianthus Annuus

Sow seeds outdoors in a prepared seed bed (or in pots of seed compost) in a sunny position, from early to mid spring. Thin to a spacing of around 12-18in (30-45cm).

Popular Varieties of Helianthus Annuus

Available in numerous strains, with varying heights and flower sizes.

Tall Varieties (above 5ft)

Helianthus annuus Claret (F1) bears multiple chocolate-brown flowers on tall stems. Height to 6ft (1.8m). RHS Award of Garden Merit. For sale at Crocus.

Sunflower 'Colossus' is a large variety with very large yellow flowers from late summer onwards. Height to 10ft (3m), spread 24in (60cm). For sale at Van Meuwen.

Helianthus annuus Garden Statement produces dark-centred, lemon-yellow, semi-double flowers on top of branching stems, throughout the summer. Height to 6ft (1.8m). Great in the garden or the vase. For sale at Crocus.

Sunflower 'High Hopes' a impressive tall variety. Height to 14ft (4.5m). For sale at Thompson & Morgan.

Sunflower 'Magic Roundabout' (F1 Hybrid) has bicoloured flowers in a mix of colours. Long flowering. Height to 6ft ( 1.8m), spread 18in (45cm). For sale at Van Meuwen.

Helianthus annuus 'Russian Giant' bears large single yellow flowers. Height to 10ft (3m). For sale at Thompson & Morgan.

Helianthus annuus 'Tall Single' can reach a height of more than 10ft (3m) with 1ft (30cm) wide, sunny-faced flowers. For sale at Crocus.

Medium Height (below 5ft)

Sunflower 'Astra Gold' is a tall, bright variety with unusual ruffled petals. Great for the back of the border. Height to 5ft (1.5m) For sale at Thompson & Morgan.

Helianthus annuus 'Autumn Sunshine' produces medium-sized flowers in combinations of yellow, bronze and red. Height to 4ft (1.2m).

Sunflower 'Elite Sun' (F1 Hybrid) produces large yellow flower heads. A compact form, ideal for the border or a large container. Height to 4ft (1.2m). For sale at Thompson & Morgan.

Sunflower 'Harlequin' (F1 Hybrid) bears bicoloured flowers in a very unusual rose pink shade. Long flowering, multi-headed stems. Height from 4-5 ft (120-150cm). For sale at Thompson & Morgan.

Helianthus annuus 'Italian White' has cream flowers with a black central disc and a gold zone. Height to 4ft (1.2m).

Helianthus annuus 'Orange Sun' has fully double, apricot-orange flowers. Height to 38in (1m).

Helianthus annuus 'Sunburst' has crimson, gold, bronze and lemon flowers. Height to 4ft (1.2m).

Sunflower 'Teddy Bear' has long-lasting round, fluffy double blooms. Ideal in containers or the border. Height to 4ft (120cm), spread to 24in (60cm). For sale at Van Meuwen.

Helianthus annuus Valentine a medium height variety with lots of smaller flowers. RHS Award of Garden Merit. For sale at Crocus.

Sunflower 'Van Gogh' a mix of the very best sunflowers that can be grown together in varying heights, each stem producing a bright, sunshine filled sunflower! Height up to 5ft (1.5m). For sale at Thompson & Morgan.

Short Varieties (below 3ft)

Helianthus annuus 'Autumn Beauty' with sulphur-yellow and a copper zone. Height to 3ft (90cm).

Sunflower 'Choco Sun' a dwarf multi-flowering sunflower, one of the smallest and quickest flowering varieties. Ideal for containers. For sale at Thompson & Morgan.

Sunflower 'Irish Eyes' a vigorous dwarf variety in golden colours. Height and spread to 18in (45cm). For sale at Van Meuwen.

Helianthus annuus 'Music Box Mixed' is low-growing variety with medium-sized flowers that range from yellow and cream to red, with black centres. Height to 28in (70cm).

Helianthus 'Sunbelievable Brown Eyed Girl' is a multiple-branching sunflower, with large, golden-yellow flowers (3-4in) across. Long flowering season from May until the first frosts. Height and spread to 2ft (60cm). For sale at You Garden.

Helianthus annuus 'Sunspot' is a dwarf form with golden-yellow flowers with yellow-green centres. Height to 2ft (60cm).

Helianthus annuus 'Teddy Bear is a dwarf bushy variety with double golden blooms. Height to 2ft (60cm). For sale at Crocus.