Lemongrass Seeds - Cymbopogon flexuosus

4, 5, 6, 7, 8, 9, 10, 11

USDA Zones 4-11 - Lemongrass is a tender tropical perennial. It can be grown in the ground year-round as a perennial in Zones 10-11. In Zones 4-9, it is grown as a very fast-growing and productive annual.

Best Performance in Zones 8-11 - Flourishes in regions with long, hot, and humid summers. These conditions allow the plant to form large, dense clumps with thick, harvestable stalks by the end of the season.

Northern Zones (4-7) - Starting seeds indoors is essential for a successful harvest. Sow seeds indoors 6-8 weeks before your last frost date. The plant must be grown as an annual or potted and moved indoors to a bright, sunny window well before the first frost in autumn.

Hot Climate Zones (8-11) - Direct sowing is possible after all danger of frost has passed, but starting indoors is still recommended for a head start. In Zones 8-9, the roots may survive winter with a very heavy layer of mulch, but it's often easier to overwinter a small division in a pot indoors. In Zones 10-11, it will grow as a true perennial.

Soil Temperature - Lemongrass requires very warm soil to germinate. A consistent soil temperature of 70-80 degrees F is necessary. A seedling heat mat is strongly recommended for successful and timely sprouting.

Growing Season - Requires a long, warm growing season of at least 100 frost-free days to produce thick, usable stalks for cooking.

Learn more about USDA Hardiness Zones here

When to Sow:
For most climates (Zones 4-9), starting seeds indoors is the only reliable method. Sow seeds 6-8 weeks before your last expected frost date. Direct sowing is not recommended unless you live in a climate with a very long, hot growing season (Zones 9b and higher).

Starting Seeds Indoors:

Sow Depth: Lemongrass seeds need light to germinate. Press the seeds firmly onto the surface of a sterile, well-draining seed-starting mix. Do not cover the seeds with soil.

Heat is Essential: Place the seed tray on a seedling heat mat to maintain a constant soil temperature of 70-80 degrees F. Germination will be very slow and poor in cooler soil.

Moisture & Humidity: Mist the seeds gently to water them in and cover the tray with a clear plastic dome to maintain high humidity. Keep the soil consistently moist but not saturated.

Be Patient: Lemongrass can be slow and erratic to germinate. Expect sprouts to appear anywhere from 7 to 40 days after sowing.

Light: Once seedlings emerge, provide at least 12-16 hours of strong light from a grow light or a south-facing window.

Transplanting Outdoors:

Harden Off: After the grass-like seedlings are a few inches tall, gradually acclimate them to outdoor conditions over 7-10 days.

Timing: Transplant into the garden only when the weather is stable and warm, and all danger of frost has passed. Nighttime temperatures should reliably stay above 55 degrees F.

Spacing: Space plants 24 inches apart to give the clumps ample room to expand throughout the season.

Growing Conditions:

Sunlight: Plant in the sunniest location possible. Lemongrass needs at least 6-8 hours of direct, hot sun per day to thrive.

Soil: Requires well-drained soil. It is not fussy about soil type but will not tolerate soggy, waterlogged conditions.

Watering: Water regularly and deeply after transplanting to establish a strong root system. While it becomes drought-tolerant once established, consistent watering will result in more tender, thicker stalks.

Fertilizing: Lemongrass is a heavy feeder. For the best growth, feed it every 2-3 weeks during the summer with a balanced liquid fertilizer that is high in nitrogen.

Harvesting & Overwintering:

Harvesting: You can begin harvesting once the stalks at the base of the clump are at least 1/2-inch thick. Use a sharp knife to cut the stalks off at soil level. Use the tender, pale bottom 4-6 inches for cooking. The leaves can be bundled and used for tea.

Overwintering (Zones 9 and colder): Before the first frost, dig up a small section of the clump. Trim the leafy tops down to about 6-8 inches and plant it in a pot. Bring the pot indoors and place it in a sunny window. Water sparingly through the winter and replant it outdoors the following spring.