Even if you're continually using your lemongrass to make yummy Southeast Asian dishes or to treat the kids to cups of delicious, lemony tea, chances are your lemongrass plant is going to need a haircut from time to time. In temperate zones, the perennial herb, also known by its botanical name, Cymbopogon citratus, can grow to a large size. The plant is hardy for U.S. Department of Agriculture plant hardiness zones 8 or lower, but in areas with frost, the plant's leaves may die back in winter and come back strong in the spring. If you're the type who likes your plants to have a neat, trimmed appearance, you may need to keep your pruning shears handy quite often.
Put on a pair of gloves in early spring, after the danger of frost has passed, in preparation for pruning. The stalks of the plant have pretty sharp edges, so you'll want to protect your hands anytime you're handling it.
Pull gently to remove any dead, brown leaves from beneath the plant and around its base. Also pull gently on any brown leaves in between the white and green living stalks; those dead brown leaves should come out easily. Make a pile of leaves and then compost them.
Hold the stalks of the plant about 8 to 12 inches from the top, and then wrap your pruning shears around the plant. Aim to cut the plant a few inches above the white stalks, which may remove anything from 6 to 18 inches of green leaves from the ends of the plant. If your plant is fairly wide and has a lot of stalks, you may have to hold the stalks in multiple places to trim the entire plant. Compost the discarded leaves.
Inspect the general shape of the plant after you've trimmed off the ends. At this point, the remaining leaves may look perkier and the whole plant may take on a rounder or more oval shape. If you're the type who likes your plants to maintain a neat, symmetrical appearance, step back and look for places to trim more leaves, creating an oval or round shape with the leaves.
Trim the stalks a few inches above the white part anytime throughout the spring and summer if they start to look wilted or brown.