Lemongrass Winter Care: How to Prepare for the Cold

As a tropical plant, lemongrass isn’t exactly suited to the chilly temperatures of winter in much of North America. When temperatures fall below 40ºF, it begins to suffer.

A close up of a cluster of lemongrass stems growing in a pot with long upright stems and light green grass like leaves, on a bright soft focus background. To the center and bottom of the frame is white and green text.

However, there are ways to help this herb survive the cold, and come back healthy and vigorous in spring. Continue reading to find out how to prepare your plants for winter.

Plant Hardiness Zones

If you’re growing lemongrass in your garden, you might be wondering what to do with it over the winter months. Due to its tropical origins, lemongrass can only survive the winter outside in the warmest areas of the US.

A close up of lemongrass plants with upright bright green leaves growing outdoors in a raised bed. To the left of the frame is a wooden sign in the ground amongst the plants.

If you live in USDA Hardiness Zone 10 or 11, it’s safe to leave it outside year-round. However, this only applies to growers in Florida, southern Texas, southern Arizona, and southern California.

If you live in Zone 8 or below, you’ll need to bring your plants inside during the colder months or they’ll end up dying. In Zone 9, it’s best to bring them indoors, but with additional protection you should be able to overwinter them outside.

Protecting Outdoor Plants

If you’re in Zone 9, your lemongrass can survive the winter outdoors as long as you provide adequate protection from the cold.

Floating row covers can act almost like a blanket, covering and keeping plants warm when temperatures plummet.

A lemongrass plant in the garden with its leaves cut back making a small compact form. In the background is grass, straw mulch and bushy vegetation.

The first step in preparing for the cold months is to prune your lemongrass. Using gardening shears, remove the leaves and cut the stalks back until they are six to twelve inches tall.

Then drape the material over the plant.

Make sure to hold down the sides using rocks, bricks, or other weights to make a snug cover. Gather each end and weigh down to prevent cold air from blowing in.

Divide, Prune, and Pot

If you live in Zone 8 or below, you’ll need to bring your herbs inside during the winter where they will go dormant.

A close up of a lemongrass plant growing in the garden, with long thin bright green leaves and vegetation in the background.

When they are dormant, they can survive the cold, dark days. Think of dormant plants like hibernating bears; they both take it easy in the winter so they can kick into action in the spring.

If you’re bringing them inside for the winter, you’ll want to start preparing your lemongrass when nighttime temperatures start to drop below 45ºF.

The first step to getting this grass for life indoors is to divide it.

First, use a shovel to dig up the whole plant. Make sure to dig at least two inches either side of the base of the stem in order to preserve the roots.

A close up of a lemongrass plant growing in the garden, its leaves cut down. On the right of the frame is a spade in the ground with a wooden handle, ready to dig the plant up. In the background is grass and soil in bright sunshine.

After you’ve dug it up, use your hands to carefully separate each lemongrass clump into sections of two to four stalks. Make sure each section contains roots.

If it contains less than four stalks, you don’t need to divide it.

After dividing, use scissors or pruning shears to cut the leaves and stalks back so they are 6-12 inches tall.

This haircut helps the maintain moisture in the upcoming months by decreasing the surface area it uses to respire. With fewer leaves, less water evaporates from the leaves.

For more information on dividing perennials see our full guide here.

A close up of a black pot with dark, rich soil and a lemongrass plant, on a concrete surface. The background fades to soft focus.

The next step is to pot them up.

Choose a container that is at least six inches wide and six inches deep. Fill the container with a mix of soil and compost, and plant the stalks 1-2 inches deep.

If placing more than one section of stalks into the same container, space them at least one inch apart.

Keeping Plants Indoors

Once your herbs are in their pots, you need to find a proper location for them to spend the next few months.

Two hands from the left of the frame holding a rectangular terra cotta container with lemongrass plants in rich soil. In the background is grass and a concrete wall in soft focus.

Since  overwintering lemongrass is going to be dormant, don’t expect growth or harvests over the cooler months.

To maintain dormancy, place the pots in a cool, dimly lit area. These conditions will keep it alive, but not actually growing. A garage, basement, or cellar kept at 50-60ºF are good options.

Water your lemongrass about once a month over the winter while it’s dormant. Only water sparingly, when the soil is dry at the top; the goal is to provide just enough water for the dormant plant to survive.

A close up of a plastic terra cotta colored rectangular container with lemongrass plants pruned so only their stalks are left, and the leaves removed. The pot is on a wooden surface and the background is a brick wall.

If you don’t have a cool area, they can be kept in a warmer environment. The warmth will likely prevent them from going fully dormant, although growth will slow dramatically.

In warm space (above 60ºF), plants will try to continue to grow throughout the winter. In this case try to provide your lemongrass with plenty of light by placing it near a south-facing window.

A black metal planting container with pruned lemongrass plants cut back to a few inches high on a concrete surface with a soft focus background.

If you don’t have a window with sufficient light, you can provide artificial light via a grow light. A simple light-bulb will do – just look for one labeled “cool white.”

If you want your plant to continue growing, make sure it gets at least ten hours of natural or artificial light each day. Water twice a week to keep the soil moist but not waterlogged.

Preparing for Spring

Once daytime temperatures are regularly in the 50s, move your pots to a sunny and warm location indoors. Start watering them with about a quarter of an inch two to three times a week.

A black plastic pot containing rich dark soil and a lemongrass plant with light stems and green upright leaves, on a gray tiled surface. In the background is grass lawn.

After two weeks of acclimation to light and warmth, you can begin moving the containers outside during the day. Be sure to bring them inside if the temperature dips to 40ºF or below.

Once nighttime temperatures remain reliably above 40ºF, you can leave your them outside. At this point, you can also transplant them back into your garden if you wish.

While you can transplant your herbs back into their previous location, it’s best to place them somewhere new. By practicing crop rotation, you help prevent problems with disease, pests, and nutrient-deficiency in the soil.

Wherever you end up transplanting, make sure the soil is well-aerated. Plant clumps of one to four stalks, with one to two feet between each clump.

Will My Lemongrass Survive Winter?

If you follow the steps above, your lemongrass will survive the winter. Even if you don’t make it to the tropics yourself, you’ll have a reminder of the warmth that is to come.

A row of lemongrass plants growing in the garden with long, thin, upright, green leaves. In the background are trees and vegetation in soft focus.

If you have any questions about how to prepare this herb for the colder weather, please comment below.

And to learn more about tropical plants, check out these articles:

© Ask the Experts, LLC. ALL RIGHTS RESERVED. See our TOS for more details. Originally published on December 12, 2019. Last updated: March 9, 2020 at 17:38 pm. Uncredited photos: Shutterstock. With additional writing and editing by Clare Groom and Allison Sidhu.

About Briana Yablonski

Briana Yablonski grew up in Eastern Pennsylvania and currently resides in Knoxville, Tennessee. She holds a Bachelor of Science degree in plant sciences and has worked on farms in Minnesota, Pennsylvania, Virginia, and Tennessee. Now, she spends many hours planting seeds and moving compost at her market garden. When she’s not immersed in the world of gardening, Briana enjoys walking dogs at the local shelter and riding her bike. She believes that gardening fosters curiosity, continuous learning, and wonder.

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Khane
Khane (@guest_10054)
2 months ago

Is it possible to create a new lemongrass genes that will survive winter? How does one pollenate lemongrass?

Allison Sidhu
Allison Sidhu (@allison-sidhu)
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Noble Member
Reply to  Khane
1 month ago

Lemongrass is a tropical plant, so it would be difficult to hybridize one that is truly winter hardy. However, seeds saved over multiple generations from the same region do tend to develop qualities that are uniquely suited to their growing zone. If you live in a location with mild winters, and you have plenty of time for experimentation, you might like to give this a try. The flowers are typically wind pollinated and they are monoecious, meaning they have both male and female parts. You could try keeping your plants isolated and pollinating them by hand for the purpose of… Read more »

Lisa
Lisa (@guest_10143)
1 month ago

Hi there! Thanks for all this great info! I’m in NY and will be bringing my lemongrass plants in for the winter. I’ll be cutting them back and keeping them on a shelf in the hallway by the balcony door. There is a radiator across from where they’ll be and a roof access hatch above them. I’m thinking the temp will be above 50-60 degrees in this location so will need to give them the light they’ll need. I see you say you can use a regular lightbulb as long as it’s a cool white one. Does this mean I… Read more »

Allison Sidhu
Allison Sidhu (@allison-sidhu)
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Noble Member
Reply to  Lisa
1 month ago

White LEDs can work as grow lights, since they provide mix of red, blue, and other wavelengths of light that plants will appreciate. But the output of regular LED light bulbs like you’d use to light your house don’t typically provide enough power for the job, so grow lights are recommended. Grow lights usually produce a significantly higher output. Unfortunately, I don’t think a 60-watt bulb will do much for your plants if your aim is to grow them year-round indoors, but for winter dormancy in New York you actually want to keep them in a cool, dimly lit location… Read more »

Jun Marro
Jun Marro (@guest_10574)
14 days ago

hi Briana
My question : I have lemongrass growing in pots and in the ground. I will be bringing the pots in but can I dig up the ones in the ground and re-plant them in pots? Will they survive? I started growing them not for consumption but because the plants look good in the yard.
Thank you!

Clare Groom
Clare Groom (@clareg)
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Member
Reply to  Jun Marro
12 days ago

Hi Jun,
Yes you can absolutely dig them up and plant them in pots. Depending on the size of your plants, this is also a good time to divide them. You can then replant in your garden in spring.