Caring for Sunflower

Sunflowers have moderate water needs and establish a deep taproot that helps them tolerate short dry spells once mature. Water regularly during germination and the first few weeks of growth, keeping the soil evenly moist but not waterlogged. From mid-summer onwards, water deeply once or twice a week during dry weather, directing water at the base rather than overhead to reduce the risk of fungal issues. Plants grown in sandy soil may need more frequent watering than those in loam. Feed once in June, just as flower buds begin to form, using a balanced general-purpose fertiliser or a tomato feed diluted according to the packet instructions. Avoid high-nitrogen feeds later in the season, as these promote leafy growth at the expense of flowers and seed development. A mulch of garden compost applied in late spring provides a slow-release nutrient boost and helps retain soil moisture through summer. Sunflowers are hardy annuals and will not survive winter; they complete their life cycle in a single season and are killed by the first frosts. There is no overwintering required. Save seed from your best plants in October for sowing the following spring, storing them in a cool, dry place in labelled paper envelopes. Pests are generally few, but birds—especially goldfinches and sparrows—love ripening seeds. If you want to harvest seeds yourself, cover developing heads with horticultural fleece or netting once petals fade. Aphids occasionally cluster on young stems and buds; squash small infestations by hand or spray with soapy water. Powdery mildew can appear on leaves in dry summers with cool nights, but it rarely affects flowering or seed set seriously. Good spacing and air circulation help prevent it.