How to Grow Lemongrass in Colder Climates

Container Plants

• Lemon grass cannot tolerate temperatures below 40 degrees Fahrenheit. It will grow as a garden bed plant in the summer but is permanently killed back by the first frost in late fall or early winter. This means lemon grass plants grown in cold climates are annuals that require replanting each spring after frost danger passes. Growing lemon grass in pots allows you to keep the plant as a perennial. Grow the potted lemon grass outdoors during the warm season and bring the plants indoors in winter to protect them from frost.

Potting Requirements

• Plant lemon grass in 8-inch-diameter containers with an 8-inch depth to ensure enough room for the roots to spread. The container must have a drainage hole in the bottom so the soil doesn't become overly wet. Use a quality potting soil or make your own by combining equal parts potting soil or compost, perlite and peat moss. Grow only one lemon grass plant per pot. Sow the plant root at the same depth it was growing at previously. Planting too deeply can cause the stalk to rot.

Basic Care

• Provide moist soil conditions by watering the soil in the pot before it begins to dry out. Outdoor plants in summer may require irrigation as frequently as once daily, while indoor plants may only need once-weekly watering. Keep the pots in a sunny location whether you grow them indoors or out. Lemon grass requires at least six hours of daily sunlight. Fertilize the plant during the summer with a soluble nitrogen fertilizer applied weekly at half the strength recommended by the label. The plants don't require winter fertilization.

Overwintering

• Bring potted lemon grass indoors before temperatures drop below 40 degrees. Locate the pot in a south-facing, sunny window in a warm room. Avoid locations subjected to cold drafts from open doors or drying air from nearby heat vents. Lemon grass requires humid conditions so may require daily misting with water in the dry environment inside most homes. You can move the plants back outdoors in early summer after the temperatures raise and all danger of frost has passed.