Pruning Lemongrass: How to Tame That Wild Thing

Is your lemongrass plant looking a bit unwieldy like Cousin It? This tropical perennial herb will grow as big as you let it, continuing to multiply and put out new stalks as the older ones die back. And it can get messy quickly! Learn how to give your lemongrass a haircut with my step-by-step pruning guide.

Linda Ly
Two-year lemongrass update (and how to tame that wild thing)

When I propagated lemongrass (purchased from the grocery store) for my garden, I started with only three stalks and planted them in the ground once the roots reached a few inches.

They were given ample sun, weekly watering in the summer, no (or hardly any) watering in the winter, and quickly grew into something that kinda resembled Cousin It.

That original bundle of three little stalks looks like this now.

Overgrown lemongrass clump

And embarrassingly, this is what it looks like most of the year as I’m kind of a lazy gardener. The shrub-like herb has multiplied into a clump of at least 50 stalks, with the whole plant spanning 4 feet wide by 4 feet high.

I don’t often trim it or divide it, but since it’s spring and lemongrass doesn’t really get going again until summer, it was high time to give it a much-needed haircut.

Here’s how you can tell your plant is dormant, plus my simple technique for pruning lemongrass and keeping it healthy all year long.

When does lemongrass go dormant?

Lemongrass (Cymbopogon citratus) enters dormancy when temperatures start to dip below 45°F.

In USDA Hardiness Zones 10 and above, lemongrass slows down in winter and doesn’t put out as many new leaves each week. The plant is still green, but its leaves will look a bit bedraggled after a long growing season.

In zones 8b and 9, you’ll think the plant has died as the leaves turn brown in winter. But not to worry!

Lemongrass roots are typically hardy in zones 8b and 9. With a frost blanket or heavy layer of straw mulch over the soil, lemongrass (a tender perennial herb) has a good chance of returning year after year (even when the leaves die back).

Colder zones need to overwinter lemongrass indoors before the first frost hits. It’s happiest in a dimly lit room that’s kept at 50°F to 60°F (like a basement or garage), where it stays dormant through the cold, dark days of winter.

Special note for overwintering lemongrass: Cut the leaves off to keep the plant tidy and manageable, and water sparingly so it stays alive through the winter months. (It won’t grow during this time, but will happily hang out until it’s ready to kick into action again in spring.)

Healthy lemongrass clump

When should you prune lemongrass?

The best time to cut back your lemongrass is while it’s dormant, but not until temperatures start to warm up in spring. This can be anywhere from late February to late April, depending on your climate.

Nighttime temperatures should stay consistently in the mid-40°Fs for lemongrass to successfully bounce back from an early-season trim.

How to cut back lemongrass in cold climates

If you’re in zones 8b to 9, your job is easy: simply pull back the frost blanket (or mulch) and cut down the entire plant to just a couple inches above the tender white part of the stalk, removing all the brown leaves.

(Do this for overwintered lemongrass too. You can start to harden off the plant outside once it’s been pruned.)

It feels a bit shocking, I know, but as summer creeps closer, your lemongrass will grow back quickly.

How to cut back lemongrass in mild climates

Gardeners whose plants stay green all winter just need to maintain the shape of the shrub. Light pruning of the leaf tips can be done throughout the year, but a heavy pruning should be done in spring to give your lemongrass a chance to grow stronger and healthier.

To begin, rake out all the dead leaves under the plant. (If this is your first time pruning, you might be surprised by how much organic matter accumulates under there.)

Then put on some gloves (those leaf edges are paper-cut sharp!) and pull out any brown outer stalks as well as brown or rusted leaves.

You may have to reach in between the clump to get all the leaves out (but leave the inner stalks intact, as those are the newer ones). Generally, I give a light tug and anything dead comes out easily.

Dead lemongrass leaves

Once you’ve removed all the brown bits, use hedge shears to cut back the leaves. I just do a straight cut across, trimming one section of leaves at a time (similar to trimming bangs, if you’re into home haircuts).

Homegrown lemongrass
Pruning lemongrass

Trim as much as you want, as lemongrass can take a pretty good pruning. I like to trim my plant into a Tina Turner-esque mound of grass, keeping it short and neat.

Growing lemongrass

Once you’ve got the shape you want, you can finesse the cut and go all Edwards Scissorhands on it, trimming random brown tips here and there until your OCD wears off.

When finished, you should have a shapely green clump with healthy white stalks.

Healthy lemongrass stalks

The arrival of summer will spur your lemongrass to grow vigorously again, and new leaves will fill out the plant more.

Did you know? Lemongrass (Cymbopogon sp.) is sometimes called the citronella plant, as that’s where citronella oil (a natural mosquito repellent) comes from. But confusingly, it’s not the only citronella plant: the so-called “mosquito plant” (Pelargonium ‘Citrosum’) also goes by that common name.

How to tell them apart? Simple: Cymbopogon is a tall perennial grass, while Pelargonium ‘Citrosum’ is a member of the geranium family (and recognizable by its leaf shape).

Newly pruned lemongrass mound

How to maintain lemongrass throughout the year

If you don’t use your lemongrass that often, try to keep the clump in check by removing wilted outer stalks once a month.

Maintaining your plant (simply by harvesting it) helps reduce the spread of pests and diseases. (Lemongrass is susceptible to rust, a fungal infection that favors warm temperatures and high moisture.)

Or, you can dig up healthy stalks with the roots intact and replant them elsewhere in your garden to thin out the clump. If you’re doing some major dividing, you can even pot up a few stalks in soil to give as gifts!

Try this recipe: Fresh Lemongrass-Ginger Ale

This post updated from an article that originally appeared on May 1, 2013.

45 Comments

  1. Sounds like many of you grow lemongrass for decorative purposes but we use it a lot in southeast Asian cooking. It adds great flavor to fish stews, beef laab (Thai ground beef salad), finely chopped into homemade jerky dip, and my mom brews it as a herbal remedy for diabetes and high blood pressure.

  2. Thank you for a really informative page! I live in Lincolnshire UK and have three large pots of lemon grass growing in my greenhouse. I was going to put them in the soil there, but have now decided to pot them on and have them on my patio for the summer. I shall be making lemongrass cordial as well!

  3. Hi Linda,

    I just started growing my lemongrass. It’s produced new stalks but I’m noticing white fuzz / very fine hair on the stalks. Is this normal?
    Some of my other houseplants were attacked by mealybugs but I don’t think this is the case with the lemongrass..

  4. Hi Linda,
    I recently went extreme Edward Scissorhands and cut down all my lemongrass to 2 – 3 inches above ground. It’s Spring now in Houston (with the summer humidity right around the corner) and besides the frequent rains, I also water my plants regularly. How long would you guesstimate it growing back to edible height or thickness? Thanks!

  5. Hi,

    Slightly different conditions as I live by the Med.

    No frost but night down to 10C. and seasonal rain.

    Now back to 20C so growing again but do the brown leaves inhibit growth?

    With plenty water thrive and leaves grow (about 1 in. per day after trimming) during the summer.

    Thanks you help,

    Ian

  6. Hi again. Put 3 in a plastic pot with slightly damp home-made compost all around and into our garage. Will check in a month or so to check moisture level.

    1. Hi, that should work. You should also periodically mist the leaves with water (or bring the
      pot into the shower, the way you do with houseplants) to increase humidity levels and keep the plant happy. I actually overwinter my lemongrass in the greenhouse as it stays pretty humid in there (we heat it with a giant hot compost pile).

      1. Thanks for your reply. I did cut the leafs to the ground before I moved into the garage. BTW, it sounds like you moved to Bend. We visit there 1-2x a year. Lots to do there and many good restaurants.

  7. Hi Linda, we are in southern Oregon and temps get into 20’s. I dug out/trimmed back, 3 of our 1 y/o lemongrass and am not sure how to overwinter. I plan to leave in our garage (usually in the 50’s,) in a box or container with peat or rice hulls. Do I need to keep damp or if dry….will they croak ? TIA.

  8. I thought my lemongrass made a comeback but now it has NO SMELL. Unless the new blades take time to develop an aroma, I think a different grass may have taken up residency right on top of what was formerly lemongrass. I still don’t know for sure, so I’m not reusing the pot for something else, until I’m certain that’s not my lemongrass anymore.

  9. just saw this post.. I see you are in oregon. Do you think the lemongrass can be outside all winter long in seattle ?

  10. That is the best ever description on how to prune something. I hope you have these guides for kiwi fruit, passion fruit and many other plants!! Thanks heaps!!

  11. Great how-to on the lemongrass (or “fever grass” as the local islander told me off the coast of Nicaragua as I was sweating and shivering for a couple days there with dengue fever. “Have da lady ova deh make you some tea wit dis.”, he said, as he cut it from the jungle and wrapped it up nicely for me.)

    MY lemongrass plant in the backyard was a 2’+ diameter, 2′ tall dense beauty a few months ago, and then I didn’t water it for a long time, and about 90% of it died off brown and crunchy, and I’ve been wondering what to do with it – so thanks for your article!

    I can add this – I took some of that dried crumbly dead leafage and made tea with it – it was great! I guess it’s like dried herbs, but they just dried on the stalk naturally.

    Now if I could just find someone to put my 3’x3’x2′ lemon geranium beast to harvest and use (I don’t have the time to figure out what to do with it, but it is thriving!)

    Thanks again!

    1. Holy cow, I also got the dengue in Nicaragua! It was the summer of 2005… I was playing baseball in their professional league. Random! I’m growing lemongrass here on Delmarva. No idea it’s helpful with fevers!

  12. The nicest thing I’ve found to do with lemongrass is use its essential oil as a scent for cold process soap. One of my friends says she takes two showers a day to enjoy the soothing calming happy scent. She swears it cures anxiety and the blues.

  13. I live west of roswell,nm–the icy cold winds we had these past couple of months I think finally browned up 3 young lemon grass plants to the point I think they might be dead :(( I left them out in their square planters in a partial covered porch(I was careful about watering them during the days it got over 65 and of course I mulched them to give them warmth. My husband trimmed them the other day and I noticed out of all 3 clumps, maybe 10 leaves if that are trying to turn green. It’s still February and we’ve had above 70 deg temps–will they come back and any advise what to do with them at this point will be greatly appreciated. I wish there was a way to upload pics of them here 🙁

  14. Can the lemongrass be grown in just a big pot of water? We live in high rise apartments with limited space and no garden. We use 3-4 stalks a week for cooking and i thot we should grow them instead.

    1. No, you’ll have to move the lemongrass to a container once you’ve rooted the stalks. They grow to fit the space you give them, so they’ll be fine in a 1-gallon pot but if you’re using 3-4 stalks a week, you’ll want to put them in a 3-gallon pot or bigger. Keep in mind they also grow quite large and bushy, and require ample sun.

  15. This is my first year I am growing lemongrass from seed. How do I know when to harvest this herb. Also I live in Chicago, is there an way I can keep some for the winter months, I just love it in soup.

    1. I have never grown lemongrass from seed so I don’t know how long it takes for harvest. But I’d assume you can start harvesting when the stalks look like the ones you’d find in a store. I pull mine when they’re about the size of my thumb.

      If you want lemongrass to survive the winter, you should start some in a pot indoors. You can also freeze the stems and dry the leaves.

  16. Nice! I bought a clump for our flower garden as an ornamental with intentions to use it for cooking. Glad to know it’ll get nice and bushy! Do you dry any of the green cuttings or is it best used fresh?

    1. You can dry the leaves to make herbal teas (and I imagine they’d be nice for infusing broths), but I have so much lemongrass that I always just use it fresh.

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