Artemisia annua aka Sweet Sagewort

Artemisia annua is also known as sweet wormwood. It belongs to Asteraceae, the daisy family. This annual comes from southeast Europe and western Asia. It is not native to Britain or Ireland. PFAF also notes wild groups on northern China's steppe. There, it grows at heights of about 3,300–4,900 feet [1,000–1,500 metres]. The plant has a long history in Chinese herbal medicine.

Sweet wormwood grows fast and has a tall, neat form. PFAF gives a height of about 10 feet [3 metres]. Its spread reaches about 3.3 feet [1 metre]. Its scented leaves suit the space behind shorter border plants. It can fill gaps at the back of garden beds. Its height and scent give it value beyond its flowers. The supplied sources give no details of leaf shape. Nor do they describe the colour of its stems.

PFAF says flowers appear from August to September. Each flower has both male and female organs. Insects carry pollen to the flowers. The plant can also use its own pollen to form seeds. Seeds ripen from September to October, after the flowers bloom. Shorter days prompt plants to bloom once past their young stage. PFAF also notes that the plant draws wildlife. The supplied evidence gives no details of its fruit.

Choose a sunny site with soil that drains well. It can grow in light shade, though PFAF favours full sun. It grows in sand and loam, even with few nutrients. The soil can be slightly acid, neutral, or slightly alkaline. Soil may be dry or moist, but must drain well. PFAF lists USDA zones 6–9 and calls it easy to grow. Sow seed under cover in spring, then plant out later. You can also sow straight into the ground in late spring. PFAF reports few pest or disease problems. Yet it has become a weed on disturbed ground in many places.

Oil from the leaves adds flavour to spirits, including vermouth. The plant also yields scented oil for use in perfume. In China, people grow fungi on it for use in winemaking. PFAF lists uses in folk medicine, including treatments linked to malaria and fever. These uses do not prove that home-made remedies are safe. Skin contact can cause dermatitis, a form of skin rash. It can cause other allergic reactions too. Its pollen can also cause strong allergies. These risks matter when choosing where to grow or handle it.