taken from The Georgia Fruit and Vegetable Book by Walter Reeves and Felder Rushing
Tender perennial. A native of India, Lemongrass grows in clumps 4 to 6 feet high. Leaves have a fragrance resembling the scent of lemons. C. nardus is the source of citronella, a popular, oldfashioned insect repellent. It grows well in full sun.
Buy started plants or divide old clumps and plant when the weather is safe. Cut off the outer leaves at the base as needed. Use them fresh or dry them in a dark room to preserve the green color. The lower sections of the stalks are peeled, chopped fine and pounded to release their flavor for stir frying. The dried leaves make an excellent tea or addition to tea.
In Zones 7b and colder, take a few starts inside for the winter. Dig up a section with a short piece of root in October while it is still warm outdoors. Cut the long leaves back and plant it in a small pot. It will survive fine in a very sunny window.