Licorice candy brings back fond memories of childhood, but homegrown licorice root (Glycyrrhiza glabra) is healthier. Hardy in U.S. Department of Agriculture plant hardiness zones 7 through 9, licorice grows 48 inches tall and 39 inches wide, and its fibrous, edible roots have a characteristic flavor that's 50 times sweeter than sucrose. Also called sweetwood and sweet root, this perennial bears violet, blue-violet or lavender summer flowers, but these should be removed to concentrate the plant's energy into developing extensive roots. Licorice fixes nitrogen from the air in its root nodules, which help feed the plant and surrounding vegetation.
Things You'll Need
- Organic mulch
- Slow-release, 12-4-8 fertilizer
- 2-percent metaldehyde, 5-percent carbaryl slug granules
Grow licorice in full-sun or partial-shade sites in deep, moist, loose soil, such as moist sandy or stony soil. Licorice thrives in full sun and slightly alkaline soil and doesn't tolerate clay soil. Space plants 24 to 36 inches apart.
Water licorice regularly during the growing season so that the soil is constantly moist but never sodden. Spread a 2-inch layer of organic mulch, such as well-rotted manure or compost, avoiding the plant's stems.
Feed licorice with slow-release, 12-4-8 fertilizer granules, spread at a rate of 4 tablespoons per 4 square feet at the beginning of the growing season or according to the manufacturer's instructions. Apply the fertilizer again after three months.
Examine licorice leaves and stems weekly for holes and other signs of slug attack. Check plants after dark with a flashlight or at first light to catch slugs and squash them. Alternatively, water the ground if the surface is dry and scatter 2-percent metaldehyde and 5-percent carbaryl slug granules lightly around licorice plants. Sprinkle water to wet the granules lightly and don't apply water again for at least two days. Spread slug granules every two weeks or as frequently as needed.
Pinch off licorice flowers between thumb and forefinger as they appear during summer.