Lemongrass is harvested for its thick, lemon-scented stalks, and the harvest is satisfyingly simple: choose a stalk as thick as your finger, grip it low, and twist and pull it from the clump. The plant is a tender, tropical grass that grows fast in warm weather and must be harvested before frost, so the main harvest comes in late summer and autumn, when the stalks are at their thickest and most aromatic.
Lemongrass takes 90–120 days to mature, according to the Garden Grove crop data. It is a tender herb in the Poaceae family with moderate water needs. For the full growing picture, see our growing guide for lemongrass, and use the Harvest Date Calculator to work out your picking window from your sowing date. Browse the full guides hub and the tools hub for more harvest timing advice, and check your local extension service for dates suited to your climate.
Lemongrass at a glance
| Growing factor | What lemongrass needs |
|---|---|
| Days to maturity | 90–120 |
| Category | herb |
| Family | Poaceae |
| Cold tolerance | tender |
| Water needs | moderate |
Signs lemongrass is ready to pick
A lemongrass stalk is ready when the base is at least as thick as your little finger — ideally as thick as your thumb — and the lower part of the stalk is pale, swollen and firm. The leaves should be long, arching and bright green, and the whole clump should be at least two feet tall. Thin, grassy stalks are still young and have little flavour in the base; thick, woody stalks are over-mature and fibrous.
Check the colour of the stalk base. A ready stalk has a pale yellow-green base that feels solid and heavy when you grip it. If the base is thin, soft or hollow, the stalk is not ready. The scent is a useful check too — snap a leaf and it should smell strongly of lemon. If the scent is weak, the plant may need more sun or more water, or it may simply need a few more weeks of warm weather.
How to pick lemongrass
Harvest lemongrass by gripping a stalk low down, close to the base, and twisting it sharply while pulling upwards — the stalk should snap away from the clump with a clean break. Alternatively, cut the stalk at ground level with a sharp knife or secateurs. Work around the outside of the clump, taking the thickest stalks first and leaving the young, thin shoots in the centre to keep growing.
Wear gloves and long sleeves, because lemongrass leaves have sharp edges that can cut skin. Take only a few stalks at a time from any one clump, and never remove more than about a third of the clump at once. Harvest in the morning after the dew has dried, when the stalks are crisp. For the full growing picture, see our growing guide for lemongrass.
The best time of day to harvest
Harvest lemongrass in the morning, after the dew has dried but before the sun gets hot. That is when the leaves are dry, crisp and most aromatic, because the essential oils are at their most concentrated after a cool night. Leaves picked in the afternoon heat are often limp and less flavourful, and wet leaves picked while the dew is still on them dry slowly and can go mouldy in storage.
Choose a dry day for harvesting if you can, and avoid picking after rain, when the foliage is wet and heavy. If you must pick on a damp day, spread the cuttings out in a single layer in a ventilated spot for an hour before you bundle or bag them. And get the harvest out of the sun straight away — a basket of cut herbs left in the sun for an hour will wilt and lose much of its aroma. Morning picking is a small habit that makes a real difference to flavour and keeping quality.
How often to pick
Lemongrass is a pick-little-and-often crop, and regular picking is part of good plant care, not just a way to get a harvest. Once the plant is established, you can take a small picking every week or two through the growing season, always leaving enough growth for the plant to recover. Each cut encourages the plant to branch and push out fresh, tender growth, so a plant that is picked regularly stays bushy and productive far longer than one that is left alone.
Do not wait for a single big harvest unless the plant is one you cut whole for drying — for most herbs, steady, small pickings give you better flavour and a healthier plant. Take a few sprigs from several plants rather than a large handful from one, and always leave at least two-thirds of the plant intact. If you go away for a few weeks, ask someone to pick the herbs, or cut the plant back before you leave so it regrows while you are gone.
What happens if lemongrass is left too long
Lemongrass left unharvested does not spoil quickly, but the stalks become increasingly woody and fibrous, and the flavour concentrates in the tough outer layers rather than the tender core. An old clump becomes a dense tangle of stems with thin, weak growth in the centre, and the stalks that remain are hard to use in cooking.
If your lemongrass has become a woody tangle, cut the whole clump back hard in spring, divide it, and replant a young section in fresh soil. The old stalks can still be used for tea or stock if they are sound. The main risk is frost: a single frost will kill the leaves and damage the stalks, so take a final harvest before the first frost and check your local extension service for your frost dates.
How to store lemongrass
Fresh lemongrass keeps for two to three weeks in the fridge, wrapped loosely in a bag or stood in a jar of water. For longer keeping, freezing is excellent — chop the tender lower stalks into pieces and freeze them in bags, or freeze whole stalks and chop them while still frozen. Frozen lemongrass keeps its lemon flavour for months and is ideal for curries, soups and teas.
To use a stalk, trim off the leafy top and the tough outer layers, and use the pale, tender lower six inches — that is where the flavour is. The leafy tops can be dried for tea, and the tough outer layers make a fragrant addition to a stock pot. Drying the stalks themselves is less successful than freezing, because dried lemongrass loses much of its aroma — freeze it if you can.
Succession and continuous harvest tips
Lemongrass is a tender perennial with moderate water needs, so in warm climates it lives for years, but in cold climates it is grown as an annual and must be harvested before the first frost. The plant grows fast in warm weather, so a single clump started in spring will give you stalks from late summer onwards. There is no need to sow succession batches — one clump is usually enough.
In cold climates, lift a small division of the clump in autumn, pot it up and bring it indoors for winter, then plant it out again in spring after the last frost. Keep the plant well watered in summer, because lemongrass is thirsty in hot weather and drought-stressed plants produce thin, weak stalks. Mulch thickly to hold moisture and feed the clump in early summer for the thickest stalks.
If you are also growing other herbs and vegetables, our guides to harvesting tarragon and harvesting catnip follow the same picking principles, and check your local extension service for advice suited to your area.
Frequently asked questions
When is lemongrass ready to harvest?
When the stalk base is at least as thick as your little finger and pale, swollen and firm, typically 90–120 days after planting.
How do I cut lemongrass?
Grip a stalk low down, twist sharply and pull upwards, or cut it at ground level with a knife. Take the thickest outer stalks first.
Can lemongrass survive frost?
No — it is tender and frost kills it. Harvest before the first frost, and in cold climates lift a division to overwinter indoors.
Should I freeze or dry lemongrass?
Freeze it. Frozen stalks keep their lemon flavour for months, while dried lemongrass loses much of its aroma.
Which part of the stalk do I use?
The pale, tender lower six inches. Trim off the leafy top and the tough outer layers — the flavour is in the swollen base.