Sunflowers (Helianthus annuus) are fast-growing annuals, from dwarf pot varieties under 50 cm to giants over 3 m. Sow directly outdoors in May after the last frost, 2–3 cm deep, or start them in pots indoors in late April, which gives a head start and protects seedlings from slugs, their main early enemy. They need full sun, deep, fertile soil (pH 6.0–7.5) and space – about 40–60 cm between tall plants. Water regularly, especially while buds form, and stake tall varieties in windy sites. Young plants turn with the sun during the day; once they flower, most heads settle facing east. Sunflowers attract bees and many other insects, and branching varieties grown for cutting keep flowering for weeks if cut regularly. When the back of the head turns yellow-brown and the seeds are plump, usually in September, cut the head with a length of stem, cover it with a paper bag against birds and hang it to dry. Leave a few heads standing as winter food for birds.