Gardeners grow lemon grass (Cymbopogon citratus) for its bulb and foliage, which exudes a citrus-like scent and adds flavor to many types of entrees. The grass grows up to three feet tall, according to Washington State University, and can also be used as an ornamental grass in standard landscapes and herb gardens. Though you can buy lemon grass seedlings in some nurseries, it's usually cheaper to grow your own plant by rooting a lemon grass cutting.
Obtain a cutting. Lemon grass cuttings can be purchased in specialty ethnic stores or from the produce section of some grocery stores and consist of the grass stalk connected to a portion of its bulbous end. Cooks typically use the bulbous end for culinary purposes, so it's always left intact. Alternatively, make a cutting from an existing plant. Select a healthy stalk on the outer edge of a lemon grass bunch. Slice it off at the soil level so that a portion of the stalk's bulb is still attached.
Trim off any foliage that's connected to the piece of cut bulb. Leave approximately two to three inches of the stem. Failing to remove the lemon grass foliage can cause the cutting to dry out quickly and die.
Fill a gallon-sized pot with potting soil. If commercially prepared soil isn't available, prepare your own by combining equal parts of soil, peat moss or compost, and sand or perlite.
Bury the cut bulb in the soil. Sink the bulb deep enough that it's completely submerged except for the narrow top portion of the bulb.
Water the pot twice daily, or as needed, to keep the soil consistently moist. The cutting will typically take root within two weeks and will send up new grass shoots as it extends its roots.