How to Grow and Care for Lemongrass (Plus, Uses Benefits)

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Lemongrass, Cymbopogon spp.

Lemongrass is an aromatic tropical grass cultivated primarily for culinary use. There are two of the 55 species in the genus Cymbopogon that are used almost interchangeably as lemongrass. The so-called East-Indian lemongrass (C. flexuosus) (also known as cochin or Malabar grass) is native to India, Sri Lanka, Burma and Thailand, while West-Indian lemongrass (C. citratus), is of a Malaysian origin and is more typically used for cooking. When crushed, the fragrance resembles the scent of lemon. Extensive breeding programs have developed many varieties of lemongrass but few are available in North America. The related citronella grass (C. nardus) is the source of commercial citronella oil, which is used in soaps, as a mosquito repellent in insect sprays and candles and in aromatherapy.

This perennial herb is widely grown in the tropics and subtropics but can also be grown as an annual in cooler climates. The plants grow in dense clumps up to 6 feet in diameter, with leaves up to 3 feet long. They require warm, humid conditions in full sun to thrive. The coarse, strap-like leaves are ½-1” wide, finely serrated on the edges (rough enough to cut skin), tapered at the end and have gracefully drooping tips. It is not as attractive as many other ornamental grasses but clumps can develop into imposing specimens. Plants will flower with a branched cluster of stalked flowers but usually not when grown as an annual. These are not ornamental and rarely set seed.
Grow lemongrass in containers or as an annual during the growing season. Plant in full sun in moist, loam soil, preferably with high organic content. Place outside as soon as the danger from frost is past. Clumps will grow slowly until the heat and humidity of summer arrives then the plants will increase in size dramatically. This plant requires a great deal of water, so water regularly if rainfall is sparse. Frost will kill or severely damage the plants, so harvest or dig before overnight temperatures get to freezing.

Lemongrass has essentially no pest problems in the Midwest.
Propagate lemongrass by root or plant division. You may be able to root grocery store specimens in water or potting medium if enough root plate is left on the stem. Roots should form within two or three weeks if they are going to.

To harvest, cut stems at ground level when the stems are about ½” thick. Push an outside stem to the side, then twist and pull it off or cut off with a knife. Discard the leaves and woody outer layers. The entire clump can be harvested (such as at the end of the season just before the first frost), or selected stems can be removed from the edges of the clump.
When harvested, the bulbous stems look like scallions, but are pale yellow and more fibrous once the woody outer layers have been removed. The whole stalk itself is too hard to be eaten, so it is usually smashed and simmered in liquid to impart the lemony flavor to the dish, then removed before serving.
If you don’t have your own clump of lemongrass, you may be able to find it for sale in Asian markets, some grocery stores that stock specialty items, and at some farmer’s markets. Select firm stalks with fresh to slightly dry tops and a somewhat heavy and moist base.

Lemongrass is an important culinary herb in tropical Asia (in India it is cultivated as a medical herb and for perfumes, but not used as a spice). Lemongrass has a light, refreshing, lemony flavor without the bitterness that lemon rind can have and with a hint of ginger. It is a staple in Thai cuisine, used to flavor soups, fish, seafood stews, curry and sauces. It is also an important flavoring in Vietnam, Cambodia and Indonesia, being used with poultry, fish and seafood dishes.
The main constituent of both species of lemongrass, citral, has a refreshing, lemony smell is also a strong, cleansing antiseptic. The oil is steam-distilled from the fresh or partly dried stems and is used in low-cost citrus soaps, perfumes and cleaning agents. C. citratus contains enough myrcene to make the oil susceptible to oxidative polymerization. The oil from C. flexuosus contains less myrcene and therefore has a longer shelf life, so it is dominantly used in the perfume industry.
– Susan Mahr, University of Wisconsin

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How to Grow and Care for Lemongrass (Plus, Uses + Benefits)

Lemongrass or Lemon grass (Cymbopogon citratus) is a perennial, tropical grass native to South Asia, and South-East Asia. Due to its aromatic, citrusy scent and many health benefits, it is widely used in culinary, medicinal, and cosmetic applications.

This ornamental grass not only looks good but tastes great as well. In addition to being a delicious addition to soups, stir-fries, and for making teas, this fast-growing plant looks great waving in the summer breeze.

It features tall, slender, green leaves that grow in clumps. The leaves are long and arching, with sharp edges, and exude a strong lemony fragrance when bruised.

When fall arrives, the long, slender, gray-green foliage of this plant transforms into vibrant shades of burgundy and red, adding a stunning splash of color to fall gardens.

Lemongrass is native to South Asian, and South-East Asian countries such as Sri Lanka, India, Burma, and Thailand. It is perennial in zones 10 and 11 but is commonly grown as an annual in other areas.

The best time to plant lemongrass is in the spring from potted nursery plants after all threat of frost is over. It’s important to note though that this plant contains cyanogenic glycosides and other oils that are toxic to dogs, cats, and horses in large quantities.

Photo Credit: Dreamstime.

Botanical Name: Cymbopogon citratus

Common Name: Lemongrass

Family: Poaceae

Plant Type: Perennial, annual, herb

Hardiness Zones:10 – 11 (USDA)

Sun Exposure: Full sun

Soil Type: Loamy

Soil pH: Neutral

Maturity: 75 – 100 days

Height: 2 – 4 feet tall

Native Area: Asia

Table of Contents

Quick Guide: Planting, Growing and Caring for Lemongrass

• Lemongrass is an easy plant to grow that prefers full with at least six hours of direct sunlight per day.
• This aromatic culinary herb prefers moist soil but can be quite drought-tolerate once established.
• It thrives in warm, humid environments and it’s best planted outside when nighttime temperatures are consistently around 50 degrees.
• You can propagate it by division, or grow it from seeds although it’s usually trickier to find seeds.

Photo Credit: Dreamstime.

Lemongrass Plant Care

Lemongrass is easy to grow both indoors and outdoors. It thrives in environments that are similar to its native area’s warmth and humidity. And so, your lemongrass plant will grow and multiply quickly if you give it plenty of heat, light, and moisture.

What’s best is that lemongrass is a multitasking plant, thanks to its fragrance which also serves as a pest repellent. The oil from the plant appears to deter common pests like mosquitoes.

Light

Even in hot places, lemongrass grows best in full sun. The plant requires at least six hours of direct sunlight per day to meet its energy requirements. Plants that grow in the shade will not have many leaves and may attract pests.

Soil

Lemongrass grows best in loamy, rich soil. Compost, manure, and leaf mold are just a few examples of soil amendments that can be added around planting time to help achieve this goal.

Water

For best results, lemongrass prefers moist soil. Lemongrass will grow with the routine 1 inch per week watering that is recommended for many other garden plants, but it can survive with significantly less water than that. In fact, once established, it’s quite drought-tolerant as well.

Consider adding a layer of mulch that’s approximately three inches thick to help preserve soil moisture and enrich the soil as it decomposes over time.

Temperature and Humidity

Lemongrass thrives in warm, humid environments. Planting lemongrass outdoors is best done when nighttime temperatures are consistently around 50 degrees.

Lemongrass is extremely frost sensitive, so bring it indoors before temperatures dip into the 40s if you intend to overwinter it in pots.

Fertilizer

For the best growth of its green plant, lemongrass requires a nitrogen-rich fertilizer. Consider using a slow-release 6-4-0 fertilizer that will feed the plant all through the growing season.

Manure tea is another option for watering because it contains trace nutrients that will help your plant grow better.

Pruning

Lemongrass plants that thrive for more than one season benefit from an annual trim to keep them neat and remove dead leaves. The plant will naturally die back in the winter, so leave the browned leaves alone since they’ll protect the plant from frost.

At the end of winter, when plants are dormant, trim the ornamental grass to a height of about 6 inches. When warm weather returns, lemongrass plants will rapidly recover and produce new shoots.

Overwintering

Lemongrass often remains evergreen all year long in areas where it is a perennial i.e. in USDA hardiness zones 10 and 11. It may die back to the ground in the winter for gardeners in zones 8 and 9, then come back the following spring.

If you live in a cooler climate, you can bring some indoors and overwinter it in a bright, sunny spot by digging up and planting clumps clump into containers.

Photo Credit: Dreamstime.

Lemongrass Benefits

Lemongrass has many benefits, both medicinal and culinary. It is a powerful immune system booster, rich in antioxidants, and has antibacterial properties due to its high citral content. Research shows that it’s also known to help reduce stress, anxiety, and insomnia.

It can help lower cholesterol levels and blood sugar levels, making it beneficial for people with diabetes. On the culinary side, lemongrass is used to flavor soups, curry dishes, and teas and is a staple ingredient in Thai and other Southeast Asian cuisines.

Photo Credit: Shutterstock.

How to Plant and Grow Lemongrass

How to Grow Lemongrass from Seed

Lemongrass is easy to grow from seed, though it can be tricky to find seeds for sale at times. It’s more common to find small plants to start lemongrass than seeds, even with online retailers. Seeds may be difficult to come by, but if you do, they will germinate quickly and easily in warm, moist soil.

Lightly press the seeds into the sterile potting mix and maintain a moist environment until germination which typically takes around 10 – 14 days.

When the plants are about 3 inches tall, spread them out to a distance of 1 foot. Place indoor pots in a sunny area.

How to Propagate Lemongrass

Lemongrass grows in clumps which makes it quite simple to propagate it by using the division method. To do this, dig the clump or the entire root ball out of its container.

Next, use a garden trowel or spade to cut the clump into pieces. Each leaf fan will have a narrow bulb-like base with roots, and each of these has the potential to grow into a new clump.

The size of each of these divisions is up to you, but clumps containing at least five or six bulbs will appear more substantial than a single bulb

Replant the divisions right away in fresh pots or in specific garden sites. Water thoroughly when planting, and then continue watering daily while the divisions are establishing themselves.

How to Pot or Repot Lemongrass

For growing your lemongrass, pick a large container with a minimum diameter of 12 inches. This serves to support a strong root system as well as keep top-heavy plants from toppling over. If you live in a cooler region, you can keep your plant alive until the next harvest by growing a single root division in a container on a sunny windowsill.

Use a high-quality commercial potting soil when potting or repotting lemongrass. Selecting potting soil that has been pre-mixed with a slow-release fertilizer can save you time and energy when feeding your plants.

If you’ve had your lemongrass plant in the same pot year after year, you should give it a fresh start by repotting it in spring which will help replenish the soil.

Harvesting Lemongrass

Harvesting lemongrass is a different process than pruning it. Lemongrass is a plant that grows quickly, therefore it may be harvested when the plant is still young and not suffer any negative effects.

Even though the green leaves are too tough to eat, you can cut them off and let them steep in tea or broth. When mashed or minced, the stalks lend a fragrant lemon flavor to dishes.

With a hand trowel, separate the individual stalks from the clump and roots. Take off the tough outer leaves and chop or freeze the tender white stalks so you can use them later.

Photo Credit: Shutterstock.

How to Use Lemongrass

Lemongrass has a mild, delicious lemony flavor with a hint of ginger and without the unpleasant taste that lemon rinds sometimes have.

It is an essential ingredient in Thai cuisine, used to flavor soups, fish, seafood stews, curry, and sauces. It’s also popular in Vietnam, Cambodia, and Indonesia, where it is used to season poultry, fish, and seafood dishes.

To cook with fresh lemongrass, always cut off the bottom bulb and pull off the tough outer leaves. Thai cuisine uses the main stalk, which is the yellow portion. You can cut the yellow stalk into pieces that are 2 to 3 inches long and ‘bruise’ them by turning them several times.

Also, use your knife to make shallow cuts along these parts. This will help the lemon flavor come out. Throw these bruised stalks into a stew or curry.

Remove the lemongrass pieces before serving, or ask your guests to do so as they eat. You’ll have a delicious lemon flavor and aroma in all the recipes you use this in.

Other uses of lemongrass in cooking include steeping it to make lemongrass tea. Moreover, it’s also valued for its lemongrass essential oil which has antibacterial, anti-inflammatory, and antifungal properties. It’s commonly used in aromatherapy, cosmetics, and as a natural insect repellent.

Common Pests and Plant Diseases for Lemongrass

Lemongrass plants are free of most pests, thanks to their pest repellent properties. However, they may be susceptible to rust fungus in certain areas. Brown streaks or spots on leaves are signs of the condition, which kills plants. To keep plants from getting rust, water them at the soil level instead of from above the leaves.

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