Borago officinalis aka Borage

Borago officinalis, or borage, is an annual herb. Starflower and cool tankard are other names for it. It belongs to the forget-me-not family, Boraginaceae. Its native range covers the western and central Mediterranean. It grows in temperate climates beyond its native range. In Britain, it occurs on waste ground near houses. It is not native to Britain or Ireland.

Garden plants reach about 1.6–3.3 feet (0.5–1 metre) tall. They spread up to 1.6 feet (0.5 metre) wide. The plant branches and forms a spreading clump. It grows at a moderate rate. Stiff hairs cover both its stems and leaves. The simple, oval leaves have a dull, grey-green shade. Their wrinkled blades reach 0.5 feet (0.15 metre) long. Stems and tender leaves smell and taste like cucumber. Dried leaves lose their flavour.

Blue, star-shaped flowers hang from branched cymes in summer. Each flower measures less than 0.08 feet (0.025 metre) across. Missouri Botanical Garden gives June to August as flowering time. Other sources also report flowers into autumn. Bees visit the blooms, which attract other wildlife too. Borage suits herb beds, wild gardens, and cottage gardens. It also grows in borders and containers. Its flowers provide colour among plants grown for food. They yield a blue dye that turns pink with acid.

Borage grows best in full sun but accepts partial shade. It tolerates poor soil and a wide range of textures. Acid, neutral, and alkaline soils all suit it. Good drainage matters more than rich soil. It accepts dry to moist conditions and tolerates drought. Sources also report resistance to deer. RHS rates it H5; Missouri Botanical Garden lists USDA zones 2–11. It needs little care and grows from seed. It dislikes transplanting and can return through self-sown seedlings. Slugs and leaf-mining flies may harm the leaves. Powdery mildew can occur, though serious problems are uncommon.

People use leaves raw or cooked, and flowers as garnishes. The leaf hairs can make whole leaves unpleasant to eat. These food uses come with a safety warning. Borage contains pyrrolizidine alkaloids that can harm the liver. NC State also warns of lung damage and possible cancer risk. Its profile flags risks to cats, dogs, and horses. People with liver problems should avoid its leaves and flowers. Use only seed oil certified free of these alkaloids. Historical herbal uses do not remove these safety concerns.