For gardeners looking to get the most bang out of their real estate buck, edible landscaping fills two desires: increasing curb appeal, while also getting tasty fresh veggies, fruits, and herbs for the kitchen. Some plants billed as ornamental edibles are questionable in either their beauty or their deliciousness (how many of those ornamental peppers can you really eat in a week?), but few plants marry looks and tastiness the way lemongrass does. A fast-growing ornamental grass, lemongrass is as handsome waving in the summer breeze as it is appetizing in your soups, stir fries, and teas.
- Botanical Name: Cymbopogon citratus
- Common Name: Lemongrass
- Plant Type: Ornamental grass
- Mature Size: Two to four feet
- Sun Exposure: Full sun
- Soil Type: Rich and loamy
- Soil pH: Neutral; 6.8-7.2
- Bloom Time: No flowers
- Flower Color: None
- Hardiness Zones: 10-11
- Native Area: Sri Lanka and India
Caring for Lemongrass
Lemongrass grows with abundance in areas where conditions mimic the tropical habitat of their origin. Plants like lots of heat, light, and moisture: Provide this, and your lemongrass will grow and multiply quickly.
In its native habitat, lemongrass grows in full sun, even in hot climates. At least six hours of direct sun per day will meet the plants' energy needs. Plants growing in shade will be sparse and may attract pests.
Lemongrass plants prefer rich, loamy soil. You can create this ideal soil by adding a number of different soil amendments: compost, manure, and leaf mold are all enriching additives that you can add at planting time.
Unlike some ornamental grasses, lemongrass is not a drought-tolerant plant. Keep the roots constantly moist for best plant health. A three-inch layer of mulch can help conserve soil moisture, and will enrich the soil as it breaks down.
Temperature and Humidity
As tropical plants, lemongrass thrives in hot, steamy climates. The time for growing lemongrass outdoors is similar to the timing for tomato planting: when night temperatures are in the 60's, it's time to plant. Lemongrass is very frost sensitive, so if you plan to overwinter the plant indoors, bring it inside before temperatures get into the 40's.
As a grassy plant, lemongrass needs a nitrogen-rich fertilizer for best growth. You can use a slow-release 6-4-0 fertilizer that will feed lemongrass throughout the growing season. You can also water your lemongrass plants with manure tea, which will add trace nutrients.
Potting and Repotting
Use a high-quality commercial potting soil for potting up a lemongrass plant. Choosing a potting soil premixed with a time-released fertilizer can save you an extra step in feeding your plants. If your lemongrass plant grows in the same container year after year, it's best to repot in the spring to replenish the soil.
Lemongrass grows in clumps that make it very easy to divide. You can combine your harvesting and dividing tasks, as both require digging the plant. Each leaf fan will be attached to a narrow bulb-like base with roots attached, and each one of these has the potential to become a new clump. It's up to you how large you want each division to be. Replanting a division with at least five or six bulbs will look more substantial than a single bulb. The bulbs break apart readily with a spade or hoe.
Toxicity of Lemongrass
According to the ASPCA, lemongrass can cause stomach upset in cats and dogs, and difficulty breathing in horses. Keep plants out of reach of pets.
Lemongrass plants that live for more than one season benefit from an annual haircut to tidy up plants and remove dead foliage. Shear your plants to about six inches high at the end of winter, when plants are in their resting phase. Lemongrass plants will rebound quickly and send up new shoots when warm weather returns.
As a fast growing plant, lemongrass can withstand harvest when plants are young without any adverse effects on growth. Although the green leafy portions are too tough to eat, you can snip them for tea or steep in broth. The juicy stalks are edible when mashed or minced, adding a fragrant lemon note to dishes. Use a hand trowel to remove individual stalks, roots and all, from the clump. Remove the tough outer leaves and prepare the tender white stalks by chopping, or freeze whole stalk pieces for later use.
Being Grown in Containers
Choose a large container for growing your lemongrass, at least 12 inches in diameter. This is both to accommodate a healthy root system, and to prevent top heavy plants from tipping over. In cold climates, you can grow a single root division in a small container in a sunny windowsill to keep the plant going for next season's harvest.
Growing From Seeds
Lemongrass seeds germinate easily in warm, moist soil. Press seeds lightly into sterile potting mix, and keep moist until germination occurs, usually within about ten to 14 days. When plants are about three inches tall, thin them to a foot apart.
Common Pests and Diseases
In some areas, rust fungus can affect lemongrass plants. Symptoms include brown spots or streaks on leaves, leading to plant death. Prevent rust by watering plants at soil level.
Lemongrass vs. Lemon Verbena
Although both lemongrass and lemon verbena (Aloysia citrodora) will both make a pleasing cup of tea, the plants have a different appearance and different growing requirements. Where lemongrass is a moisture-lover, lemon verbena plants like it on the dry side. Lemon verbena plants have elongated leaves, but they aren't grassy. Unlike lemongrass, lemon verbena plants produce small white flowers, which are also edible. Lemon verbena plants are better suited for use in cold dishes, as the essential oil is delicate and evaporates during cooking.