Glycyrrhiza glabra

Liquorice Fabaceae

A plant with perhaps the most recognisable flavour in the herb garden, Glycyrrhiza glabra is a robust, deciduous perennial grown primarily for its long, creeping roots, which contain the intensely sweet compound glycyrrhizin. Above ground it forms an attractive, upright clump of pinnate, soft-green foliage, while sprays of small lilac to bluish-purple pea-like flowers appear in summer. The flowers are modest, but the plant itself is handsome enough to earn a place beyond the purely medicinal garden.

Native across a remarkably broad area from southern Europe and the Mediterranean through western and central Asia to China, liquorice is typically found in sunny, relatively dry habitats, particularly river valleys, disturbed ground and areas with deep, fertile soils.

Its ethnobotanical history is extensive. Liquorice root has been used for thousands of years in traditional European, Middle Eastern and Asian medicine, and was valued historically as a soothing ingredient for coughs and digestive complaints. It remains an important flavouring in confectionery, beverages and tobacco. The dried root can be chewed or used to make liquorice extracts, although excessive consumption of glycyrrhizin-rich liquorice can cause serious electrolyte and blood-pressure disturbances.

In cultivation it is surprisingly easy given a warm, sunny position. Plant it in deep, fertile, moisture-retentive but well-drained soil, where it can develop its extensive root system. Once established it is reasonably drought tolerant, although growth is stronger with adequate summer moisture. Be warned: its creeping roots can make it rather more enthusiastic than its innocent appearance suggests.

Height: 1–1.5 m
Spread: 60–100 cm
Flowering: June–August
Hardiness: H5, approximately –15 to –10°C
Growing conditions: Full sun; deep, fertile, well-drained soil with reasonable summer moisture. Avoid shallow or permanently wet ground.