Lemongrass (Cymbopogon spp) is a tropical grass native to the tropical areas of Asia, Africa and Australia. The most commonly used lemongrass is C. citratus which is native to Southeast Asia. It is used for cooking and medicinally, commonly in a tea in Ayurvedic medicine. C. nardus and C. winterianus are used for their citronella oils which can be found in soaps, insect repellents and aromatherapy. The oil is also used as a preservative in old manuscripts.
The part of the plant that is used is the thick stem. It is cut off at ground level. The roots and the flat grassy blades are removed, then the outer fibrous layer is peeled away revealing the fleshy heart of the stem. This soft inner stem is used sliced in dishes. The flat grassy blades can be used to flavor teas and broths.
Lemongrass is hardy in zones 9 and 10, occasionally in zone 8. It grows in clumps that reach 2 to 3 feet in height in well-drained soil and full sun. In colder climates, lemongrass is grown in containers and brought indoors during the winter or if grown in the ground, in the fall the clumps are dug up and divided then planted into containers to spend their winters inside.
To grow your lemongrass in a container, use a pot that is at least 12 inches wide or 5-gallon bucket and high quality potting soil. Place your container in an area that is protected from the wind. The plants get top heavy and the containers will easily tip over in windy conditions.
When outdoor temperatures reach 40⁰F, bring your container indoors. If you wish to continue to harvest from your plant, place it in a bright, south-facing window and lightly water it. Expect it to grow much more slowly during the winter. If you don’t plan to use your plant during the winter, you can store it in a cool, dark place like your basement where it will remain dormant. Water only occasionally to keep the roots moist. When the container is moved back outside in the spring, the plant will begin growing normally again.
You can grow lemongrass from seed. Start your seeds in late winter. Plant them ¼-inches deep. Heat mats are useful in keeping the seeds at a 70⁰F temperature. Keep them moist, but not wet. Germination should occur in 5 to 21 days. You can transplant your seedlings outside when temperatures reach 50⁰F.
Harvesting can begin when the plants are at least 12 inches tall and the stems are at least ½-inch in diameter. Lemongrass stems that have been peeled and sliced can be frozen for later use in plastic bags. Minced and pureed stems can also be frozen.