Licorice (Glycyrrhiza glabra): The Sweet Root of Herbal Medicine and Confectionery

Botanical Profile

Family: Papilionaceae (pa-pil-ee-uh-NAY-see-ee)
Genus: Glycyrrhiza (gly-ky-RY-zuh)
Species: glabra (GLAY-bruh)

Description

Licorice is a deep-rooted perennial legume growing 3–5 feet tall with pinnate leaves of 9–17 leaflets. In late spring to early summer, it bears spikes of pale blue to lavender pea-like flowers. The plant's fame lies in its extensive root system: a main taproot with horizontal rhizomes that can reach 3–4 feet deep and spread widely. The roots are brown outside, yellow inside, and intensely sweet.

Cultivation

Requires full sun, deep, fertile, well-drained sandy loam, and a long growing season. Hardy in zones 7–10; in cooler zones, grow as an annual or in deep containers. Plants take 3–4 years to develop harvestable roots. Space 2–3 feet apart. Once established, very drought tolerant due to deep roots. Nitrogen-fixing; improves soil.

Chemistry & Uses

The primary sweet compound is glycyrrhizin (glycyrrhizic acid), 50–100 times sweeter than sucrose. Used globally in herbal medicine for soothing mucous membranes (coughs, sore throats, ulcers), adrenal support, and anti-inflammatory effects. The root extract flavors candies, tobacco, beverages, and pharmaceuticals. Caution: Excessive consumption can cause hypertension, hypokalemia, and edema due to mineralocorticoid effects. Deglycyrrhizinated licorice (DGL) is safer for long-term use.

Harvest

Dig roots in fall of the 3rd or 4th year. Wash, cut, and dry. Yield: 1–2 lbs dry root per plant after 4 years.