Lemongrass (Cymbopogon citratus) is a tropical grass prized for its intense, clean, citrusy flavor. This perennial species forms dense, grassy clumps and is a staple in Southeast Asian cuisine, teas, and essential oils. Successful cultivation depends on replicating the plant’s native warm, sunny environment. This guide provides practical advice to help you grow a vigorous and flavorful harvest, whether planting in the ground or in a container.
Understanding Climate Suitability
Lemongrass is a true tropical plant. It is hardy only in the warmest regions, specifically USDA Hardiness Zones 9 through 11. In these areas, where temperatures rarely drop below 20°F, lemongrass grows back reliably each spring as a perennial. Outside of these warm zones, the plant must be treated as an annual or brought indoors for protection. Prolonged exposure to temperatures below 40°F halts growth, and a single hard frost can kill the foliage back to the ground.
Essential Environmental Conditions
Vigorous growth and maximum flavor production require full, direct sun for at least six to eight hours every day. Planting near a south-facing wall or in a spot that reflects heat encourages the rapid growth this tropical herb prefers.
The soil must be rich in organic matter, loose, and highly well-draining (pH 6.5–7.0). Heavy clay or poorly draining soil causes root rot, even though the plant requires consistent moisture. Amending the planting site with compost or aged manure achieves the ideal loamy texture.
Consistent watering is necessary. Keep the soil evenly moist without allowing it to become waterlogged. Checking the top inch of soil and watering when it feels dry helps maintain this balance.
Choosing Your Planting Method
The decision to plant in the ground or a container is dictated by your region’s climate. In zones where the plant survives winter, in-ground planting allows the plant to reach its full size. Spacing of 18 to 24 inches between clumps is required because the plant spreads through underground rhizomes.
For gardeners in colder climates or those with limited space, container growing is the most effective solution. Because lemongrass has an aggressive, fast-growing root system, select a large container (at least 5 gallons or 14 inches in diameter). Using a smaller pot risks the roots becoming pot-bound.
Container plants must be moved indoors before the first expected frost, ideally when nighttime temperatures fall below 50°F. Cut the foliage back to about six inches to reduce its size for indoor placement. During its dormant winter period, keep the plant in a cool, bright location and water minimally, only enough to keep the soil from drying out.
Propagation and Harvest
Lemongrass is easily started from stalks sold in grocery stores, provided the entire bulbous base is intact. Place stalks in a glass with an inch or two of water and keep them in a sunny window until new roots emerge. Once roots are two to three inches long and new leaves sprout, the stalk is ready to be transplanted into soil.
The fast-growing grass is a heavy feeder and benefits from consistent nutrient supplementation throughout the growing season. Apply a high-nitrogen liquid fertilizer or diluted fish emulsion every couple of weeks to support development. Incorporating a slow-release granular fertilizer at planting time provides a strong nutritional foundation.
Harvesting can begin once stalks reach a half-inch thickness at the base and are about 12 inches tall. To harvest, use a sharp knife to cut the stalk at ground level, or gently pull an entire stalk from the clump. The white, swollen, lower portion of the stalk is the primary culinary part used for its concentrated lemon flavor.