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Black Sugar

Glycyrrhiza glabra (glih-sir-RIZ-ah GLAY-bra)

Family: Fabaceae Non-native Herbaceous

Licorice is a flowering, herbaceous perennial legume native to Europe and parts of Asia. Its roots produce an intensely sweet compound used in teas and candies. Its genus name is derived from the Greek for "sweet root" and it has been used for centuries as a source of glycerin, a sweetener and a component in folk medicines. Plants with similar flavoring but not botanically related are anise, fennel, and star anise. The sweet compound is glycyrrhizin and is 50 to 170 times sweeter than sugar (sucrose). The extract has antiviral, anti-inflammatory, antioxidant, antimicrobial, and antimutagenic properties. The earliest record of use of this plant medicinally is 2100 BC. Consumption in high doses is toxic. Licorice extracts are treated to remove the majority of glycyrrizin, the problematic ingredient, prior to use in products, leaving enough to maintain flavor but decreasing toxicity. Licorice requires deep well-cultivated fertile moisture-retentive soil for good root production and prefers a sandy soil with abundant moisture. It does not flourish in clay. Slightly alkaline conditions produce the best plants. It can tolerate high winds, but not salty coastal winds or clay soils. Plant growth is initially slow, but once established the species can become weedy and difficult to remove if not kept under control by regular harvesting. Diseases, Insects, and Other Plant Problems: spider mites, slugs, snails, powdery mildew, and rust.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 71 attributes.

How it fits the guild

Guild layer 4 - Herbaceous Optimal soil pH Alkaline (>8.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Full plant profile

Growing Conditions
Plant type
Edible; Herb; Herbaceous Perennial; Poisonous
Life cycle
Perennial
USDA zones
6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11a, 11b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Loam (Silt); Sand
Soil pH
Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist
Available space
12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Growth rate
Rapid
Maintenance
Medium
Canopy layer
4 - Herbaceous
Form & Appearance
Habit / form
Arching; Clumping; Mounding; Multi-stemmed
Texture
Medium
Foliage
Deciduous
Leaf color
Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately)
Leaf arrangement
Alternate
Leaf shape
Elliptical; Lanceolate; Oblong
Leaf margin
Entire
Leaf feel
Soft
Leaf value
Edible
Leaf size
3-6 inches long, < 1 inch wide
Hairs present
No
Leaf detail
2 3/4 to 6 inches long; 1/2 by 3/4 inch wide. The leaves have 4 to 7 pairs of leaflets.
Fall color
Insignificant
Flower color
Blue; Purple/Lavender
Flower value
Edible
Flower form
Raceme
Flower shape
Funnel
Flower size
< 1 inch
Flower detail
Half-inch, sweet pea-like flowers are born on 4 inch long clusters. Flowers are light pink to light blue in color. They emerge from June to July.
Bloom time
Summer
Fruit color
Brown/Copper; Red/Burgundy
Fruit type
Legume
Fruit size
< 1 inch long, 1-3 inches wide
Fruit detail
The fruit consists of a 1/2 inch pitted pod containing 3 to 5 brown seeds.
Stem color
Cream/Tan; Gold/Yellow
Stem detail
The hairy stems are upright, growing to about 3 feet tall .
Wildlife & Ecology
Native status
Non-native
Origin
Europe, northern Africa, and Asia
Distribution
world-wide
Wildlife value
This plant provides shelter for beneficial insects and other animals, provides nectar for pollinators, is a nitrogen-fixer, and prevents soil erosion.
Attracts
Pollinators
Food & Medicine
Edible parts
Roots
Harvest time
Fall
Fruit type
Legume

Edibility

Extracts and oils of the root of this plant are used in candies and as a sweetener in foods and tobacco products.

Uses (ethnobotany)

An extract of the root is used as a sweetener or flavoring agent in confections. Licorice extract or oil is also used in foods, beverages, cosmetics, and toothpaste. It used in Ayurvedic (holistic) medicine to enhance the immune system, treat peptic ulcers, as an expectorant, a liver enzyme stimulant, a laxative, and a diuretic.

Landscape Use
Landscape location
Meadow; Naturalized Area
Landscape theme
Edible Garden; Pollinator Garden
Design feature
Specimen
Garden tags
#herbaceous perennial #medicinal #poisonous #nitrogen fixation #herb garden #fragrant roots #edible
Problems & Resistance
Insect problems
Twospotted Spider Mite; Slugs and Snails Found on Flowers and Foliage
Resistant to
Dry Soil; Erosion; Poor Soil
Propagation
Division; Root Cutting; Seed
Fire risk
low flammability
Poison severity
Medium
Poison parts
Roots
Poison symptoms
Symptoms of licorice toxicity include headache (from hypertension), edema in face and ankles, muscle cramps, dark urine, and heart arrhythmia.
Toxic principle
High doses of glycyrrizin, found in root extracts, produces glycyrrhizic acid (GZA).
Contact dermatitis
No
Toxicity summary
Medium severity poison; parts: Roots

Planted at Hunnicutt

Nobody’s planted this one yet.