You Don't Need a Garden to Grow Lemongrass—Here's How to Do It Indoors

Lemongrass (Cymbopogon) is a popular herb in Thai and Vietnamese cuisine—it can be brewed into a tea, used as an ingredient in a delicious stir fry, and much more. The tropical plant's common name comes from its lemony fragrance—and while you can easily grow lemongrass as an annual, you can harvest it year-round as a houseplant.

Of course, there are a few things you should know before starting lemongrass at home—from the best fertilizer to the ideal pot size. Additionally, since the herb has tropical origins, it requires slightly more specific care. Here, we talked to herb experts and got their best tips for growing this versatile and appealing plant.

When to Plant

You can start growing lemongrass as a houseplant any time of the year. "Lemongrass easily adapts to indoor conditions," says Susan Betz, a master gardener and the author of Herbal Houseplants. "[It] makes a stunning, useful, fragrant accent plant when provided with the proper light and nutrients."

When grown outdoors, lemongrass is only a perennial in Zones 9 and higher and must avoid freezing temperatures. Indoors, though, the plant can be grown virtually anywhere. If you can't find lemongrass at a nursery, Betz suggests checking the fresh produce department at your local grocery store for pieces with stems.

How to Plant

Ready to get started? While you can certainly grow lemongrass from seeds, it's more commonly propagated by division or stem cuttings. Here's how to do it.

Propagation by Division

For this method, simply divide the existing plant and its rootball into multiple smaller clumps, then repot each in its own container. This is one of the easiest ways to propagate lemongrass since it rarely flowers. Look for plants at reputable nurseries—once you have an established specimen at home, you can divide it further to create more plants.

Propagation by Stem Cuttings

Stem cuttings are another easy way to propagate lemongrass. "I typically buy lemongrass cuttings with roots attached, then put them in water to root some more," says Zongxee Lee, an herbalist and community partner at the Minnesota Landscape Arboretum. "When I see the roots are at least 1 to 2 inches, I’ll pot it if growing indoors."

Once the plant begins to take root, Betz suggests moving the container to a window that receives direct sunlight. "Always provide good drainage and keep the soil from drying out completely," she says. "Lemongrass is shallow rooted and cannot withstand dry soil."

Repotting

Lemongrass can quickly outgrow its container. "Signs that your lemongrass needs repotting include roots growing out of the drainage holes, the plant becoming root-bound, or the plant toppling over due to the weight of the foliage," says Betz.

This tropical plant can easily grow to be 3 to 5 feet tall, so you may need a fairly large container. "You'll want to grow it in a pot that's at least 12 inches in diameter," says Kim Roman, owner of Square Foot Gardening and author of "Growing Herbs for Health, Wellness, Cooking, and Crafts."

Care Instructions

Your heat-loving lemongrass plant can happily thrive indoors, but you'll want to be sure to provide the ideal conditions for maximum success.

Sunlight

Lemongrass comes from the sunny tropical regions of southeast Asia, so it needs an environment that simulates these conditions. "Lemongrass needs at least 6 to 8 hours of strong light to grow indoors," says Roman. "If you don’t have suitable natural light, say at a sunny, south-facing window, then you’ll need to rely on grow lights. But remember, every plant needs a period of darkness to grow well, so don’t keep the light on all night." She notes that lemongrass will do best if the room temperature is at or above 70 degrees Fahrenheit.

Soil and Water

Lemongrass needs moist soil, but you can run the risk of overwatering if you're not careful. "You’ll want to plant it in a good soil that drains well and water frequently, keeping the roots moist, but not too wet," says Roman.

The best way to check the moisture level, she says, is to stick your finger one inch into the soil, and then water if it's dry. Keep in mind that lemongrass can be slightly sensitive to chlorine too: "It will do better with water that’s been allowed to sit for 24 hours, or filtered," she says.

Humidity

Lemongrass prefers high humidity levels. "If your indoor air is too dry, then you’ll want to mist the plant every day or two, run a humidifier nearby, or place a large saucer filled with pebbles and water under the planter," says Roman. 

Another way to meet the plant's humidity needs is to use a greenhouse. "My lemongrass grows in a greenhouse that's more humid than a typical home," says Debra Knapke, horticulturist and author of Herb Gardening in the Midwest. "I probably water once or twice a week, depending on how much sun we get. In a house it would be similar, but the tips of the leaves may brown due to the low humidity."

Fertilizer

Nitrogen is critical for the growth of all plants—they use it to create the chlorophyll necessary for photosynthesis. It can also help plants grow and develop their leaves—and since your lemongrass is basically all leaves, this can be a helpful additive. "Your plant will grow better if given a half-dose of a liquid, nitrogen-rich fertilizer every other week," says Roman. 

How to Harvest

Your lemongrass should be ready to harvest after about three months, once the plant is at least 12 inches tall, says Roman: "The base of the stalk will be thicker than the upper blades, and pliable. The drier top parts of the leaves can be cut and used for a lemony tea. The fleshier bottom stem is what you’ll use in cooking."

Betz recommends harvesting fresh lemongrass as needed. "Remove leaves a few stems at a time by cutting at the white bulbous base of the plant’s fibrous leaves," she says. Due to the plant's hard texture, Lee suggests using it mainly for flavoring.

Final Thoughts

Lemongrass is a wonderful addition to a dish or a garden, but make sure you're staying safe when working with it. "Like many grasses, the leaf edges are sharp and will make tiny cuts on one's skin," says Knapke. "Wear gloves and long sleeves."

"The blades are quite rough and can cut you if you run your hands or arms over them," adds Roman. "This happened to me the first year I grew it. Since then, I've developed a healthy respect for the plant, and I wear long gloves."