Lemon grass is a perennial which is widely used in Thai and Vietnamese cooking. In harsh climates the plant will need to be potted and wintered indoors. The herb is frequently used in curries as well as in seafood soups. It is also used to make tea. Leaves emit a lemony fragrance when bruised. Extracted plant oils have been used for many years in herbal medicines and perfumes. Depending on the area you live in, the plant will go dormant in the winter, hardy in USDA zone 10-11.