Glycyrrhiza glabra aka Licorice

Glycyrrhiza glabra, or liquorice, is in the pea family, Fabaceae. Its native range runs from the central Mediterranean to Mongolia and Pakistan. This perennial lives for years and sheds its leaves. It forms a woody base and many upright stems. Garden plants reach about 3–5 feet [0.9–1.5 metres] tall. They spread 1.6–3.3 feet [0.5–1 metre]. Growth starts at a slow pace. It becomes fast once plants take hold.

Fine hairs coat the stems, which bear green, sticky leaves. Each pinnate leaf has four to seven pairs of leaflets. These pairs grow along a central stalk. Leaves reach about 0.66 feet [0.2 metres] long. The leaflets feel soft and have smooth edges. Small, pea-like flowers form upright racemes above the leaves. These are flower clusters on a main stalk. Shades range from pale pink and blue to violet. North Carolina State gives June to July as bloom time. The RHS lists late summer. Brown pods follow, each with three to five brown seeds.

Give liquorice full sun and deep, rich soil for root growth. Keep soil moist, but let excess water drain away. North Carolina State favours sandy soil and warns against clay. The RHS lists more soil types as suitable. Both advise moist soil, though plants tolerate dry soil once established. USDA hardiness spans zones 6–11; the RHS rates it H5. Plants reach full size in two to five years. They need no routine pruning. Sow seeds in spring or autumn. You can also divide roots in early spring.

Liquorice suits informal borders, meadows and gardens that grow food. It also suits plantings for pollinators. The flowers give nectar, and the plant shelters useful insects. It also fixes nitrogen and helps limit soil loss through erosion. Once plants take hold, they can become weedy and hard to remove. Harvest roots often to help keep growth in check. Spider mites, slugs and snails may cause harm. Powdery mildew and rust can occur too. The RHS reports few pest or disease problems on the whole.

The sweet roots add flavour to sweets, drinks and other foods. They also have a long history of use in herbal medicine. Root extracts go into toothpaste and cosmetics. Industry uses the root fibres too. Wait at least three years before you harvest roots in autumn. Food uses do not mean you can safely eat unlimited amounts. Large doses can raise blood pressure and make the body retain fluid. Too much can also disrupt heart rhythm and lower potassium.