Herb · Tropical grass
Lemongrass
Cymbopogon citratusA tall, clumping tropical grass grown for its citrus-scented stalks, treated as a tender perennial anywhere winters bring frost. It needs a long head start indoors and consistent warmth to bulk up before stalks are thick enough to harvest. The one rule: bring it indoors well before the first frost, since any real cold kills it outright.
Sow depth
¼ in
Spacing
2.5 ft apart
Sun
Full sun
Germination
14–21 days
Time to harvest
120–180 days
Difficulty
Moderate
When to sow lemongrass
- Sow from about 10 weeks before your last expected frost until about 8 weeks before your last expected frost.
Start indoors early — sow 8–10 weeks before the last frost date.Surface-sow onto moist seed-starting mix and cover with a humidity dome.Keep warm, around 21–24°C, and provide good airflow to prevent damping off.
Give it room — clumps spread wide and grow tall over a full season.Water regularly; lemongrass wants consistently moist, never soggy, soil.Feed occasionally through summer to keep growth vigorous ahead of harvest.
Cut stalks at the base once they are pencil-thick and about 12 in tall.Take outer stalks first and leave the center of the clump to keep growing.Pot up a clump and bring it indoors before frost to keep harvesting over winter.
Companion plants
Lemongrass's citrus-scented oils help mask nearby vegetables from mosquitoes and aphids, but it needs steady moisture that drought-loving herbs can't tolerate alongside it.
Watch out for
Spider mites — Thrive in dry indoor air over winter, stippling and yellowing leaves. Mist regularly and raise humidity around the plant.Rust — Shows as orange-brown pustules in humid, still conditions. Space plants for airflow and remove badly affected leaves.