How to Grow the Spearmint Plant

Spearmint plant leaves

Native to central Europe, spearmint grows in sunny or partially shady locations with moist soil. The herb grows in the United States in USDA hardiness zones spearmint 4a to 11. The roots of this herb creep underground in a dense mat, from which grow the stems and leaves that reach up to 2 feet tall. As a result of spearmint's quick, aggressive growth many gardeners prefer to confine the herb to a container. Small pink or purple blooms appear from June to August.

Things You'll Need

• Spearmint seeds
• Potting soil
• Container
• Garden shears
• Liquid fertilizer or compost tea

Instructions

1. Sow spearmint seeds outdoors in a partially shady location with moist soil. Alternatively, start seeds indoors in a container with rich potting soil eight weeks before the last spring frost. Seeds may take up to 16 days to germinate. Spearmint prefers a soil pH between 6.5 and 7.0. Spearmint also propagates new plants by rooting the softwood cuttings of an adult plant.

2. Spread out the spearmint seedlings to a sunny location in the garden or in containers after seeds germinate.Provide a minimum of 36 inches growing space between each plant. Plants propagated by softwood cuttings reach their full size within four weeks. Gardeners who wish to grow spearmint in the ground but don't want to see the plant overtake their garden should plant spearmint in a container and then bury the entire container in the ground.

3. Wait to harvest until the second year. This allows the spearmint plant to develop full root strength, which serves as the basis for a strong plant. Water regularly as the plants develop to keep the soil moist but not soggy.

4. Cut back half of the stems when the spearmint plant reaches 8 inches high. Fertilize the cut area with liquid manure or a compost tea. After one month, repeat this with the previously uncut portion of the plants. This encourages regular growth throughout the summer. As spearmint plants age, the leaves become thinner and less useful in teas and other dishes.

5. Cut each stem back to within a few inches of the ground after spearmint blooms. Harvest spearmint on a dry morning to maximize the essential oils in the leaves. Gather the herbs into a bushel, tie stems together, and hang the spearmint upside down to dry and preserve for future use.

Tips & Warnings

• Spearmint seeds possess toxic qualities. Do not ingest. If you suspect spearmint seed poisoning, call your doctor, local emergency room, or the poison help hotline at [phone].

References

• Alt Nature: Spearmint, Herb Uses
• Herb Gardening: How to Grow Spearmint
• Simple Gifts Farm: Growing Spearmint
• Garden Herbs: Spearmint

Resources

• American Association of Poison Control Centers