Sunflowers (Helianthus) are the ideal annuals for wildlife gardens, beginners and children to grow - they’re quick-growing and reliable. They can range from knee-high dwarf varieties to the huge Giant Russian, which can reach 15ft (4.5m) - the one to grow for the tallest sunflower competitions. Flowers reach up to 30cm/12in across with yellow petals and dark brownish centres in the classic single stem, tall varieties. Colours range from pale lemon petals through yellow, orange, terracotta, burgundy and deep red, with the contrasting central disc.
If you want a longer flowering season, go for multi-branching types with smaller blooms, such as Garden Statement or Ring of Fire. If you deadhead this type of sunflower regularly, they’ll continue to produce new flowers until the first frosts. Read more
How to grow Sunflowers
As sunflowers are hardy annuals, they’re ideal to sow directly outside where they are to flower. Sow outdoors from March-May, placing two seeds in each 1.5cm/ ½ in deep planting hole. When they have germinated, thin out to the strongest seedling. In cooler parts of the country or if you have a cold, clay soil, try starting off sunflowers in pots indoors or in a cool greenhouse. Sow two to a 7.5cm/3in pot, thinning to the strongest seedling in April. Despite being hardy annuals, the plants will still need to be hardened off before being planted out into their final positions.
Sunflowers need a moderately fertile, humus-rich, moist but well-drained, neutral to alkaline soil in full sun and they’ll do best in a long, hot summer. Dig in some well-rotted manure or garden compost to the seed bed before planting. Some of the taller varieties need support, especially in windy sites or if the flower heads are very heavy. Tie in regularly to bamboo canes with twine.
Did You Know?
Sunflowers are an ideal plant for a wildlife garden, especially single varieties. As well as providing a rich source of food for pollinators, such as bees and butterflies while in flower, leave the dried seed heads on during winter to provide vital sustenance for garden birds such as finches. Show less