Licorice

Licorice, Glycyrrhiza glabra, the famous mulethi, is a deep-rooted nitrogen-fixing legume herb of the plains and dry valleys, native from the Mediterranean across to Mongolia and Pakistan.¹ It is best known for the sweet medicinal root, but in a planting it does double duty: as a legume it fixes nitrogen, and its long roots bind and stabilise loose soil. Grown as a low support layer, it rebuilds fertility, holds the ground, and yields a high-value medicinal crop at the same time.

Where it thrives

This is a perennial herb to about 1.2 m, hardy to roughly −15 °C.² It prefers a deep, sandy, fertile, moisture-retentive soil and does best in slightly alkaline conditions, sending roots down well over a metre that make established plants notably drought-tolerant.² That profile fits the punjab_plains, pothohar, and balochistan_highlands zones — warm plains and dry valleys with deep, often alkaline soils. The deep taproot is the key trait: it lets the plant reach water and nutrients far below the surface, so once established it tolerates the dry-season heat of the plains and the cold dry valleys alike.

Role in the system

Use mulethi as a support and soil-building groundcover layer. As a legume it fixes atmospheric nitrogen in root nodules, feeding surrounding plants, and it works as a dynamic nutrient accumulator, drawing minerals up from depth.² The deep, spreading root system binds loose soil and helps stabilise the ground, while the top growth, cut back, returns as mulch and green manure. Sitting in the lowest layer of a planting, it fills the role a cover crop plays — living mulch that shades the soil and rebuilds fertility — with the bonus that what it puts underground is itself the harvest.

What you get

The harvest is the root, and it is a serious one. The root contains glycyrrhizin, a compound about 50 times sweeter than sucrose, long used as a sweetener and flavouring in confectionery, drinks, and tea.² Medicinally it is one of the most widely used herbal remedies, valued as an anti-inflammatory, antispasmodic, demulcent, and expectorant, and taken traditionally for coughs, bronchitis, peptic ulcers, and sore throats.²³ One caution: high or prolonged intake of glycyrrhizin can raise blood pressure, so it is a remedy to use in moderation. The root is harvested after two or three seasons, once it has bulked up, which gives the plant time to do its soil-building work before it is lifted. As a crop that builds soil while it grows a high-value medicinal root, it is a strong fit for the plains and dry valleys, and the leftover crown and runners replant the next stand.

Sourcing notes

Propagate from root divisions or runners rather than seed for a reliable, named crop; it spreads readily once established. Plant in deep, well-drained, ideally slightly alkaline soil — the root crop suffers on heavy, waterlogged clay.

Sources

1. Plants of the World Online. “Glycyrrhiza glabra L.” Royal Botanic Gardens, Kew (native range).
2. Plants For A Future. “Glycyrrhiza glabra (Liquorice).” (height, hardiness, nitrogen fixation, root depth, glycyrrhizin, and uses).
3. Pakistan Journal of Pharmaceutical Sciences. “Glycyrrhiza glabra L. (Liquorice).” (medicinal constituents and uses).