Cymbopogon citratus and Cymbopogon flexuosus
Lemongrass is a warm-weather herb that’s surprisingly easy to grow at home, even in containers.
Quick Tips for Growing Lemongrass
- Needs full sun and warm temperatures
- Grows best in containers in cooler climates
- Can be grown from store-bought stalks
- Doesn’t tolerate frost
Native to Southeast Asia, Lemongrass is a versatile herb that has gained popularity among American gardeners. Its stems and leaves add fragrance and flavor to a variety of recipes, particularly in Thai, Indonesian, Vietnamese, and Cambodian cuisine.
The leaves can also be used in incense, potpourri, antifungal cleaners, hair care products, and more. Read on to learn how to grow this tropical plant in your garden, wherever you are.
Growing Lemongrass Plants in the Garden
Many herbs thrive in well-drained soil without too much fertilizer. Lemongrass isn’t one of them. Lemongrass, a tropical native, likes full sun, rich soil, and plenty of water. Work plenty of compost into your soil before planting it, and fertilize monthly.
Organic growers can use a foliar spray or soil drench of fish emulsion for fertilizing.
In warm climates, such as Florida, lemongrass is an overwintering perennial. It won’t survive the winter outdoors in cooler climates. The Wisconsin and North Carolina Extensions recommend growing lemongrass in pots year-round or digging up pieces to pot up and bring indoors before the first fall frost.
Lemongrass grows slowly in cold temperatures, but once the air and soil warm, it grows fast. Leaves may grow up to five feet long. The Universities of Florida and Wisconsin agree that you should give lemongrass clumps 3-6 feet of space. The North Carolina Extension suggests just 1-3 feet. Of course, if you keep lemongrass in a pot, it will stay considerably smaller.
As a Northern gardener, I sometimes plant heat-loving plants against the south side of a building, stone wall, or boulder. This acts as a heat sink, radiating warmth back to the plants during cool nights, while also sheltering them from the north wind.
Popular Varieties
There are more than fifty Cymbopogon species, but only two are commonly used by herb gardeners.
- West Indian lemongrass, C. citratus, is the species usually used in cooking.
- East Indian lemongrass, C. flexuosus, is often used in perfume-making because the scented oil it produces tends to keep longer.
When to Plant Lemongrass
Lemongrass is native to warmer climates. It won’t survive frost.
Set out young plants from the nursery, or from pots that you have overwintered indoors, after the last spring frost. This is also the right time to plant lemongrass seeds, but the Cooperative Extensions of Florida and Wisconsin recommend starting with plant divisions, not seeds.
How to Take Care of Lemongrass
Make sure that you keep your lemongrass plants warm, well-fed, and well-watered.
Set plants out after the last spring frost. If you live in a cold climate and have to overwinter them indoors, bring them in before the first fall frost.
Keep the soil around your lemongrass moist. It’s used to the damp heat of the tropics. If you live in a hot, dry climate, your lemongrass may also benefit from regular misting to keep the leaves from drying out.
If you’re growing lemongrass in a pot, fertilize it once a week. (Organic gardeners could use a foliar spray of fish emulsion.) If it’s planted outside in rich soil, fertilize it once a month.
When your lemongrass is small, you may need to weed it. Once it takes off in the summer heat, it can outcompete weeds quite handily.
Dividing older lemongrass clumps in the spring will help to keep them more productive.
Common Problems with Lemongrass
Lemongrass grown in good conditions is rarely troubled by pests or diseases. Still, there are some potential problems.
Spider mites may attack indoor plants, sucking the juices from their leaves. Organic insecticidal soap will deal with these.
If you don’t have mites but your plants seem to be drying out despite being well-watered, and if you notice reddish-brown blotches on the edges and tips of the leaves, your plants may have leaf blight. Prune off the afflicted leaves and discard them away from your compost pile. If that doesn’t work and the blight keeps spreading, you may need to use a fungicide.
The other fungal disease that can affect lemongrass is little leaf. The symptom is just what it sounds like: stunted leaves. (But bear in mind that small leaves could also be a result of excessively cold weather.) The Florida Extension recommends using fungicide, rather than pruning, to address this issue.
Lemongrass leaves grow thick and coarse, and their serrated edges can be sharp enough to cut skin. Handle the plant with care, and harvest in long sleeves and gloves. Don’t set it too close to other plants that you’ll want to tend or harvest with your bare hands.
Propagation: Starting New Plants
Burpee’s Seeds says that lemongrass can be grown from seed. Barely cover the seeds with fine soil, keep the seedbed moist, and watch for plants to emerge within 14-21 days.
Most Cooperative Extension publications recommend starting with plants, not with seeds. Lemongrass clumps can be divided and transplanted in spring, after the danger of frost has passed.
Growing Lemongrass in Pots
Lemongrass can be grown in pots, either year-round or just through the winter. Potted lemongrass should be placed in a bright, warm, and sunny spot, watered regularly, and fertilized weekly.
Cold-climate gardeners may want to bring pieces of lemongrass inside to overwinter. Before the first autumn frost, divide off a 6” piece of the bulbous shoot base, with roots attached, and plant it inside in a pot. Tend this through the winter and then plant it outside again after the last frost in the spring.
Can You Grow Lemongrass Indoors?
Yes, lemongrass can be grown indoors, especially in cooler climates where it won’t survive the winter outside.
It does best in a sunny window with at least 6–8 hours of light each day, or under a grow light if needed. Keep the plant warm and water regularly so the soil stays lightly moist, but not soggy
Harvesting Lemongrass
In cool climates, lemongrass is most often harvested in the fall, before the first frost. But you can harvest lemongrass at any time during the growing season once the stems are at least ½” in diameter. The fall harvest typically involves cutting down the entire plant.
If you want to bring a smaller amount in for cooking, harvest older stalks from around the edges of the plant.
Cut leafy tops off for use in teas, soups, and sauces. The Sedgwick County, KS Cooperative Extension recommends cutting them off about 18” above the ground. Stalks, which are used in many recipes, can be cut off at ground level. Sedgwick County suggests pulling stalks aside and then twisting them off at or just below ground level. The base of the stalk is the most tender and flavorful part of the plant.
Storing Fresh Lemongrass
Lemongrass leaves are typically dried for later use in soups, teas, or as a flavoring in sauces. The stalks can be either dried or frozen. Peel off the woody outer layers first. Both Burpee’s Seeds and Sedgwick County recommend chopping the tender stalk bases and then freezing them with water in ice cube trays. Frozen lemongrass will keep up to 6 months.
For more details, see our article on Harvesting and Storing Lemongrass.
Summary
Lemongrass’ fresh citrusy flavor and fragrance can liven up your food, beverages, and more. This exuberant tropical plant needs plenty of space and a little TLC and careful handling.