How to Grow Liquorice from Seeds

The roots of this shrub have been harvested for centuries as a medicine and flavouring for sweets. Liquorice is easy to grow and manage once it is established, but it should probably be left to grow for three years before the first harvest. Find out more about how to grow liquorice from seed in the guide that follows.

Latin
Glycyrrhiza glabra
Family: Fabaceae

Difficulty
Easy

Season & Zone
Season: Warm season
Exposure: Full sun
Zone: Hardy to Zone 7

Timing
Start seeds indoors around the last frost date. Transplant out once night time temperatures are steadily above 10°C (50°F). Ideal temperature for germination: 20°C (68°F). Seeds should sprout in 7-14 days.

Starting
Sow 5mm (¼”) deep. Keep the soil moist until germination — a seedling heat mat will speed germination. Transplant at a spacing of 1m (3′).

Growing
Liquorice will grow to chest height, but it can be kept a bit smaller if grown in a large container. It has an extensive root system that primarily requires good drainage. Soil fertility is less important. Liquorice is a legume that will fix its own nitrogen in the soil around its root system. It is quite cold hardy and tough once it is established.

Harvest
The roots can be harvested after the first or second year of growth. It is probably a better practice to harvest after three years by removing most of the larger roots and then re-planting each stem. Harvest in late summer.

Seed Info
Usual seed life: 3 years.

Companion Planting
As a legume, liquorice will fix atmospheric nitrogen in the soil around its roots. Leafy greens like lettuce or spinach will do well planted around the base of liquorice plants. The plants have attractive blue or violet flowers that appear August to September.