Lemongrass

A tropical grass forming dense clumps of lemony-scented stalks widely used in Asian cooking and as a natural insect repellent. In cooler climates, grow lemongrass in large containers that can be moved indoors before the first frost for overwintering. Provide rich, moist soil and full sun for the most vigorous growth, and divide clumps regularly to prevent overcrowding. Harvest stalks by cutting or twisting them at the base when they reach about half an inch thick, using the tender white inner core for cooking.

Lemongrass can be grown from seed but is most easily propagated from divisions or by rooting fresh stalks. To root store-bought stalks, trim the top and place in 2 inches of water in a sunny window. Change water every few days; roots appear in 2-3 weeks. Pot up when roots are 2 inches long. If growing from seed, sow on the surface of moist starting mix at 70-75°F. Seeds germinate in 7-14 days. Seedlings grow slowly at first and need warm conditions consistently above 60°F to thrive.

Start lemongrass from nursery plants or by rooting store-bought stalks. To root grocery store lemongrass, place fresh stalks with intact bases in a glass of water on a sunny windowsill. Roots develop in 2-3 weeks, after which you can pot up the rooted stalks. Plant outdoors after all danger of frost has passed and nighttime temperatures stay above 50°F.

Lemongrass thrives in rich, moist, well-drained soil with a pH of 6.0-7.0 and full sun. Space plants 24-36 inches apart, as each clump can grow 3-5 feet tall and 3 feet wide in a single season. Work in generous amounts of compost before planting and provide consistent moisture throughout the growing season. Lemongrass is a heavy feeder that benefits from monthly applications of balanced fertilizer.

In zones below 9, grow lemongrass in large containers (at least 5 gallons) that can be moved indoors before the first frost. Overwinter in a bright, cool location, reducing watering but never letting the soil dry completely. Cut back to 6 inches before moving indoors. In spring, divide large clumps and repot with fresh soil. Lemongrass grows rapidly in warm conditions and can reach full size in a single growing season.

Lemongrass is a natural insect repellent, containing citronella oil that deters mosquitoes, whiteflies, and other flying pests. Plant near outdoor seating areas and around vegetable gardens to reduce pest pressure. It pairs well with other tropical and subtropical herbs like basil, cilantro, and mint. The dense clumps can serve as a windbreak for smaller plants. Lemongrass is allelopathic and may inhibit the germination of some seeds nearby, so give it adequate spacing from direct-seeded crops.

Lemongrass is a heavy feeder that thrives in rich, moist, well-drained soil with a pH of 6.0-7.0. Amend planting beds with 3-4 inches of compost and add a balanced slow-release fertilizer at planting time. Feed monthly during the growing season with a nitrogen-rich fertilizer or compost tea to support its vigorous growth. In containers, use premium potting mix and fertilize every 2-3 weeks during active growth. Ensure consistent moisture, as lemongrass is a tropical plant that dislikes dry conditions.

Ideal Temperature

Hardiness Zone Compatibility

Harvest lemongrass stalks once they reach at least 1/2 inch thick at the base, typically 3-4 months after planting. Cut or twist stalks at ground level, removing them from the outside of the clump. Peel away the tough outer layers to reach the tender, pale inner core used in cooking. Leave at least 5-6 stalks per clump to sustain the plant. The leaves can also be harvested for tea and flavoring soups. Lemongrass produces continuously through the warm season and can be harvested repeatedly.

Storage & Preservation

Fresh lemongrass stalks keep for 2-3 weeks in the refrigerator, wrapped in damp paper towels in a sealed bag. For longer storage, freeze whole stalks in freezer bags; they can be sliced while still frozen and retain excellent flavor. Lemongrass can also be thinly sliced and dried in a dehydrator at 100°F for tea and seasoning blends. Dried leaves make an aromatic herbal tea. Lemongrass paste, made by blending fresh stalks with a splash of oil, freezes well in ice cube trays for convenient cooking use.

Troubleshooting Common Problems

Brown leaf tips are common and usually result from low humidity, especially indoors during winter. Increase humidity with a pebble tray or regular misting. Failure to thrive outdoors often indicates insufficient heat; lemongrass needs consistently warm temperatures above 50°F. In cold climates, delayed planting until soil is thoroughly warm yields much better results. Leggy, floppy growth indicates insufficient light. Indoor overwintering plants may develop spider mites in dry heated rooms; regular misting and inspection help prevent infestations.

Growing Tips

1. Start lemongrass from grocery store stalks by placing them in a jar of water on a sunny windowsill until roots appear, usually within one to two weeks.
2. Plant in full sun with at least six to eight hours of direct sunlight daily for the best stalk production and strongest flavor.
3. Use rich, well-draining soil amended with plenty of compost. Lemongrass is a heavy feeder that benefits from fertile growing conditions.
4. Water deeply and consistently, keeping the soil evenly moist but never waterlogged. Lemongrass prefers humid conditions similar to its tropical origins.
5. Feed every two to three weeks during the active growing season with a nitrogen-rich fertilizer to promote lush foliage and thick stalks.
6. Harvest outer stalks by grasping them near the base and twisting firmly to snap them off. Leave the inner stalks to continue growing.
7. In cooler climates, grow lemongrass in large containers so it can be moved indoors before the first frost. It needs a bright, warm spot for winter.
8. Divide established clumps every two to three years in spring to maintain vigor and create new plants for yourself or to share with fellow gardeners.
9. Cut the foliage back to about six inches in late autumn for overwintered plants. This reduces moisture loss and makes the plant easier to manage indoors.
10. Watch for rust fungus, which appears as orange-brown spots on leaves. Remove affected foliage promptly and improve air circulation around the plant.