The easy-to-care-for lemongrass plant is used as a delicious culinary herb, home remedy, and insect deterrent. It’s a highly aromatic plant with a powerful lemony citrus scent. Although commonly grown outside in tropical areas, you can start growing a lemongrass plant no matter where you live.
Popular Lemongrass Varieties
Although lemongrass commonly comes in two main varieties (East Indian or West Indian), there are tons of varieties to choose from, depending on your desired use. Ornamental lemongrass is one of the most popular options. This is the one that’s commonly featured in Thai, Vietnamese, and Cambodian meals like soups, teas, and curries. Its oil is used in aromatherapy as well as cooking.
Check out the following most popular lemongrass varieties for your garden:
East Indian Lemongrass
Cymbopogon flexuosus or East Indian lemongrass offers a strong lemon aroma with warm gingery undertones. It’s grown as a perennial in USDA zones 9-11 and grows best in a full-sun, tropical location with lots of heat and organic loam soil with great drainage. You can also grow this variety as an annual in cool climates if you plant it in a large container, as it grows tall and makes a great garden border or hedge. The leaves have culinary, perfumery, and medicinal uses.
You can use East Indian lemongrass:
- In citrus-like beverages, soups, and stir fries.
- To make potpourri and perfumes.
- For a homemade poultice for fungus infections like athlete’s foot.
- As a tea to treat anti-fungal or anti-inflammatory diseases.
West Indian (Ornamental) Lemongrass
Also known as old grass, West Indian lemongrass grows as a perennial evergreen in hardiness zones 10 and 11. This variety reaches 6 feet tall and 3 feet wide and grows in dense clumps, which makes it great for ornamental use such as privacy hedges. It does best in a full-sun location with loamy, well-drained soil, and you can propagate the clumps to make smaller plants in the summer and spring.
Citronella (Cymbopogon nardus) is the lemongrass variety that created citronella oil, which is commonly used as an insect repellent. Grown as a perennial in USDA zones 10-12, the plant won’t survive overly wet or cold winters. You can divide the clump to propagate the plant in the late summer or early fall months.
Cymbopogon winterianus, or Java Citronella, is a lemongrass species that originates in Indonesia. This plant will also grow in tall clumps with the right conditions, and you’ll need a full-sun location with plenty of moisture and sandy, loamy soil with a pH balance between 5.8 and 8. It’s a perennial in zones 9a-11, and this variety can also be grown in cooler areas as an annual.
How to Plant Lemongrass Based on Your Climate
Planting lemongrass is easy, no matter your climate. Rather than planting it from seed, the best way to start the plant is to propagate root cuttings from an existing plant or purchase an existing plant from your local nursery.
1. When to Plant
When you plant lemongrass may depend on whether you’ll be growing it outdoors or inside. If planting outside, wait until the last frost has passed. However, if you plan to keep your lemongrass plants in pots indoors, you can grow them at any time. The spring or early summer is the perfect season for starting these plants.
2. Planting Zone
You can grow lemongrass in USDA hardiness zones 9 to 12. It does well as a perennial planted outdoors in a no-frost climate, preferably a tropical or swamp-like area. The plant enjoys a good watering and part to full sun. However, you can still grow lemongrass in a colder region as an annual in containers and transfer the pots inside during the winter.
If your plants are outside, find a full-sun location with at least six hours of sunlight or partial shade. They’ll do well next to your patio or under a tall tree that can protect it from the elements. However, if they appear withered, relocate them to a shadier area.
Keeping lemongrass in containers is easy in a sunny spot as well, and you can place your pots on the patio in the spring and move them into a sunny kitchen window for the winter. A sunny window indoors, such as the kitchen, is another great spot for it.
Plants that receive less than the recommended six hours of sunlight per day may survive. However, expect the plants to grow much slower. Less than 3-5 hours of sunlight will kill off lemongrass plants.
When selecting soil, avoid a type that will dry out. Look for a well-draining bagged soil mix that retains moisture. A loam mixture with a pH balance between 5 and 8 works fine—just make sure the soil will drain well.
How to Plant Lemongrass
The easiest way to start a lemongrass plant is to propagate from an already established plant’s root cuttings. The stalks on the plant should be green, healthy, and firm to the touch before you take the cuttings.
Simply cut off a small piece around an inch or two long from the stalk with a pair of clean shears, and place it in a glass of water. Keep the glass in a sunny window while the roots form, which takes around two weeks to sprout. Then, you can plant the lemongrass in the soil after around four weeks or so.
4. Space Between Plants
Make sure to leave at least 70 centimeters of space between single plants to account for future growth. Rows of around 60 centimeters work with a minimum 90-centimeter row gap in between rows.
5. Planting Outside
Once the last frost has passed, you can plant lemongrass outside. Place each transplant at least three feet apart from each other, leaving room for the plants to reach their maximum height of six feet.
6. Planting in Containers
If planting in containers, you’ll want to leave 5 gallons of space. You can always trim the plants back as well or transplant them into either a large container or plant them outside. If the roots become too crowded in a clay container, for example, the pot can crack.
If starting your lemongrass from a purchased plant, grow it in the container until the soil is warm enough for transplanting in the early summer.
How to Care for Lemongrass
Use the following care information to help lemongrass thrive all year.
Lemongrass plants should never dry out, but how often you water your plant depends on its location. Most varieties require frequent watering. Remember that a plant in a full sun area without shade may dry out more quickly are require more frequent watering.
Maintain constant moisture levels for the best results, as the plant doesn’t tolerate dry roots for long. Muddy soil isn’t ideal either, but the leaves should be misted with water from a spray bottle in dry locations.
Because lemongrass is a tropical plant, it can freeze to death if the temperature drops under 15 degrees F. Containers or greenhouses can help keep the plants safe throughout the winter, allowing you to move them inside. Temperatures above 40 degrees F are ideal.
You can still grow lemongrass in a container if you live in a colder area. To get your plants ready for winter temperatures, use the following steps:
- Bring the containers indoors.
- Trim the stalks down to a couple of inches tall.
- Separate the stalks from the large central clump using a spade or small shovel.
- Place each stalk in a pot with soil and lightly mist the plants.
- Place the potted plant in a sunny area or return them outside when the weather warms up.
This herb requires high levels of nitrogen for survival. Fertilize your lemongrass plants every few weeks throughout the growing season using a liquid 20-20-20 fertilizer. You can also use liquid fish fertilizer, but the most important factor is that the fertilizer is nitrogen rich.
Common Problems to Growing Lemongrass
Problems growing lemongrass often pop up when the plant is not in properly draining, or is in clay soil, which causes the plants to rot. Other waterlogged diseases could become an issue as well. However, few pests or diseases plague the plant. The most common pests that affect lemongrass aphids, slugs, and snails. Spider mites may occasionally attack overwintering plants as well.
Best Companion Plants for Lemongrass
Lemongrass does great in an herb garden or when planted under a large tree to shelter it from the elements. The best companion plants for lemongrass include:
Since lemongrass plants require high levels of nitrogen, however, other plants may not survive nearby. Be careful which plants you keep nearby if you plant outdoors.
How to Harvest and Store Lemongrass
After the plant has grown to at least one foot tall, you can begin to harvest your lemongrass plant. You’ll want to cut off the entire stalk near the soil (below the swollen ends) from the outside of the plant. The stalk should be at least a half inch thick, and it’s better to cut off the stalk than to break it using your hands. If your stalks are too firm or dry, you may need to peel the outer layer off the stalks to use them.
The edible portion of lemongrass is near the top of the stalk. Cut the grassy top layer of the plant off and peel the outer layer to expose the white part inside the plant. The heart of the stalk is the part you’re after. You can store this part by freezing the whole stalk or first chopping it into pieces.