Two types of licorice root can usually be found in the market, each with a different flavor profile: sweet, anise-like licorice (Glycyrrhiza uralensis) and bitter, tannic licorice (Glycyrrhiza glabra). They have a few things in common. Both are rarely grown in the U.S., with most originating from Europe or Asia and costing as much as $45 a pound. Both also have near-impervious seed coats protecting their aromatic embryos, which makes germination a time-consuming task. To give yourself a break, you can stratify and scarify the seeds before planting them and expect 80 percent to germinate -- as opposed to untreated seeds' 80 percent failure rate.
Pour just enough water over a plastic container filled with vermiculite or coarse river sand to moisten it throughout. Use 1 quart of vermiculite or sand for every two seeds you plant. Mix the vermiculite or sand by hand.
Fill 6-inch-deep clay pots to 1 inch from the top with the vermiculite or sand. Place the licorice seeds on top of the vermiculite or sand, spacing them about 1/4 inch apart.
Cover the seeds with 1/2 inch of vermiculite or sand and place the pots individually in sealable, food-storage bags. Poke several holes in each bag using a wood skewer.
Place the pots in a refrigerator set between 35 and 40 degrees Fahrenheit for three to four weeks. Check the sand or vermiculite about once a week for moistness. Spray the sand or vermiculite a few times with water from a spray bottle if you notice it starting to dry out.
Test the soil pH in a well-draining area open to full sun or partial shade after you place the seeds in the refrigerator. If needed, amend the soil with ground limestone or elemental sulfur to reach the ideal pH range of 6.5 to 8.0.
Spread 1 3/4 to 2 pounds of ground limestone over every 25 square feet of soil and work it in 12 inches deep, using a spade fork for the task, to raise the pH by one point until it reaches 6.5. Spread 1/2 pound of elemental sulfur over every 25 square feet of soil and work it in 12 inches deep, using a spade fork for the task, to lower the pH by one point until you reach 8.0.
Remove the clay pots from the refrigerator after three to four weeks. Remove the licorice seeds from the medium and place them in a fine-mesh sieve.
Hold the seeds under cool running water to remove the medium. Scrape the seeds from the sieve and place them on a paper towel to dry.
Line the inside of a glass jar with a piece of medium-grit sandpaper, with the abrasive side facing inward. Place the licorice seeds in the jar and seal the lid.
Shake the jar for about 1 minute to abrade and weaken the seed coats, also known as scarifying the seeds. Remove the seeds from the jar and place them in a bowl of warm water for two hours.
Remove the seeds from the water and allow them to air dry on a plate or sheet pan. Mix together equal parts sphagnum peat moss or coarse river sand and vermiculite.
Fill 6-inch wide clay pots to about 1/2 inch from the lip with the vermiculite or sand and sphagnum peat moss. Plant two seeds about 1 inch apart in the pots and water them until water drains from the pot.
Place the pots in a south- or west-facing windowsill. Turn the pots a half-turn every other day to distribute the sunlight evenly over the seedlings. Water the medium as needed to keep it moist at all times. Usually 1/2 cup of water every three days suffices.
Dig the healthiest seedling from each pot, using a spoon for the task, after it reaches 3 inches tall and after the threat of frost passes in spring. Dig a hole in the planting area as the same size as the root system, about 1 to 2 inches deep and 1 inch wide, using a garden trowel.
Place the seedlings in the bottom of the hole and backfill it with the soil. Tamp the soil down gently with your fingers and water it with about 1 to 2 inches of water, just enough to saturate the roots.
Items you will need
- Plastic container
- Vermiculite or coarse river sand
- 6-inch-deep clay pots
- Sealable, food-storage bags
- Wood skewer or fork
- Spray bottle
- Ground limestone (optional)
- Elemental sulfur (optional)
- Fine-mesh sieve
- Paper towels
- Glass jar
- Medium-grit sandpaper
- Sphagnum peat moss
- Garden trowel
- You need about 1 quart of growing medium for each pot.
- Bitter licorice (Glycyrrhiza glabra) thrives in U.S. Department of Agriculture plant hardiness zones 6 through 11.
- Sweet licorice (Glycyrrhiza uralensis) thrives in USDA zones 4 through 11.
- Remove any seeds that sprout during the stratification period and plant them as soon as possible.
- Although they aren't invasive, once you establish licorice plants, they stay in that spot permanently due to re-sprouting.
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