Lemongrass (Cymbopogon citratus) is a fragrant, clumping perennial grass prized in many cuisines for its citrus aroma and flavor. Native to tropical and subtropical regions, it forms dense, fountain-like clumps of foliage. Replanting lemongrass is a common practice, allowing gardeners to propagate new plants easily from store-bought stalks or to manage the size of an established clump through division. This vegetative propagation ensures the new plant retains the desirable characteristics of the parent stock.
Preparing Stalks or Dividing Clumps
Propagating lemongrass often begins with rooting fresh stalks purchased from a grocery store, provided they have the basal plate intact. Trim any dry leaf material from the top and place the base of the stalk into a glass or jar with a few inches of water. Position the container on a sunny windowsill, ensuring the water is changed every few days to prevent mold or fungus growth. Within one to three weeks, small roots will emerge from the base, often accompanied by new green growth appearing from the top of the stalk.
Alternatively, an established lemongrass plant can be multiplied by dividing the dense root ball. This process is best performed in the spring when the plant is beginning its active growth period. Dig up the entire clump, which will be tightly bound with roots and tough basal stems. Use a sharp, sturdy spade or knife to cut the root ball into sections, ensuring each division retains a healthy mass of roots and several strong shoots attached. Trimming the foliage back to about 4 inches above the base helps the new division focus its energy on root establishment.
Determining the Best Location
Lemongrass is a tropical plant that requires environmental conditions that mimic its native habitat. The plant grows best when given full, direct sunlight for at least six hours a day. While it can tolerate some afternoon shade, abundant light encourages robust growth and a stronger aromatic oil concentration in the stems and leaves.
The ideal soil should be rich, well-draining loam with a pH ranging from 6.5 to 7.0. Good drainage is necessary, as the plant will suffer from root rot if left in heavy, waterlogged soil. Lemongrass prefers warm temperatures, with optimal growth occurring between 70°F and 100°F. Since it is sensitive to cold, planting outdoors should only occur in late spring or early summer after all danger of frost has passed and the soil has warmed.
Step-by-Step Planting Process
Once rooted stalks have developed roots at least an inch long, or the clump divisions are prepared, they are ready for planting. Dig a hole that is slightly wider and deeper than the root mass of the rooted stalk or division. If planting multiple divisions in the ground, space them approximately 24 to 36 inches apart to accommodate the mature clumping size.
Place the rooted material into the hole, ensuring the crown—the point where the roots meet the stem—sits just below the soil surface. Backfill the hole with soil, gently firming it around the base to eliminate air pockets that could dry out the new roots. Immediately after planting, water the transplanted material thoroughly to settle the soil and mitigate initial transplant shock. If planting in a container, select a pot at least 12 inches across to allow sufficient room for root expansion.
Post-Planting Maintenance
Consistent moisture is necessary immediately after planting to ensure successful root establishment. Water the plant frequently during the first few weeks, aiming to keep the soil consistently moist but never soggy. Once established, the watering frequency can be reduced, though lemongrass still prefers consistent moisture, especially during hot, dry periods.
Lemongrass is a heavy feeder and benefits from regular nutrient application throughout the active growing season. Apply a balanced liquid fertilizer every two to four weeks, or incorporate a slow-release granular fertilizer into the soil in early spring. The plant is resistant to most pests due to its aromatic essential oils, but ensure good air circulation to prevent issues like powdery mildew. Harvesting can begin when the stalks are about 12 inches tall and a half-inch wide by cutting individual stalks close to the ground to encourage new shoots.