Yes, you can successfully grow lemongrass indoors, transforming this tropical grass into a functional and fragrant houseplant. Lemongrass (Cymbopogon citratus) is a tender perennial typically cultivated as an annual in cooler climates, but indoor container growing allows it to thrive year-round. This plant is prized for its citrusy stalks, which are widely used in cooking and for making refreshing teas. Achieving consistent growth requires replicating the warm, bright conditions of its native environment, focusing on maximizing light and managing tropical moisture levels. Cultivating it indoors allows for a steady supply of fresh stalks.
Getting Started: Propagation Methods
The most common and fastest way to start an indoor lemongrass plant is by rooting a stalk purchased from a grocery store. Select fresh, firm stalks that have the pale, bulbous base intact, as this is where the new roots will emerge. Trim the top green leaves and place the bottom two inches of the stalk upright in a glass of water, ensuring the base is fully submerged.
Place the glass in a bright, warm location, and change the water every few days to prevent bacterial growth. Within one to three weeks, small, white roots will begin to sprout from the base. Once these roots are two to three inches long, the plant is ready to be transferred into a permanent soil container.
Starting from seed is an alternative, though it is a much slower process demanding consistent warmth. Seeds require light for successful germination, so they should be sown on the surface of a moist seed-starting mix and barely covered. Maintain a consistent soil temperature between 68°F and 86°F, ideally with the help of a heating mat, and expect germination to take between one and three weeks.
Essential Environmental Requirements
As a plant native to tropical and subtropical regions, lemongrass demands high light levels to sustain indoor growth. Position your container in the sunniest location available, ideally a south-facing window that receives at least six to eight hours of direct sunlight daily. If natural light is limited, the use of a full-spectrum LED grow light for 12 to 16 hours a day is an effective substitute to prevent thin, leggy growth.
Temperature is important; the plant thrives when temperatures are consistently above 70°F during the day. It should be protected from cold drafts from windows or doors, as temperatures below 50°F will cause growth to slow significantly or stop entirely. Lemongrass also appreciates higher humidity, which can be provided by setting the pot on a shallow tray filled with pebbles and water, ensuring the pot itself remains above the water line.
The container must have excellent drainage holes, and the plant requires a rich, well-draining potting mix amended with organic material. A high-quality loam will support the extensive root system this grass develops. Lemongrass is a fast grower and can quickly become root-bound, so choose a large container, at least 12 inches in diameter, for a mature plant.
Ongoing Care and Maintenance
Lemongrass requires consistent moisture throughout its active growing season, mimicking the ample rainfall of its tropical origins. Water the plant deeply when the top inch of soil feels dry to the touch, often translating to two or three times a week in warm, sunny conditions. Allowing the soil to dry out completely will stress the plant and stunt its growth, though excessively soggy soil must be avoided to prevent root rot.
During the spring and summer months, when the plant is actively producing new stalks, a regular feeding schedule is beneficial. Apply a balanced liquid fertilizer, such as a 10-10-10 formula, every four to six weeks to encourage foliage development. Reduce or cease fertilization entirely as daylight hours shorten in the fall.
While generally resilient, indoor lemongrass can occasionally attract common houseplant pests like spider mites and scale insects. Inspect the undersides of the leaves regularly, as early detection simplifies management. Treat infestations with organic options like insecticidal soap or a gentle application of neem oil, ensuring full coverage of the affected foliage.
The plant will eventually outgrow its container, typically requiring repotting every one to two years into a slightly larger pot. If the plant becomes too dense, you can divide the clump of stalks to create new, separate plants. This practice helps maintain plant health and provides opportunities for further propagation.
Harvesting and Preparing for Winter
You can begin harvesting stalks once they reach a thickness of about half an inch and the plant has established a healthy clump. To harvest, use a sharp knife to cut individual stalks at the soil line, or gently twist and pull an outer stalk away from the main clump. Avoid removing more than one-third of the total stalks at any single time to ensure the plant can continue to recover and produce.
The thick, lower portion of the stalk is used for flavoring, while the long green leaves can be trimmed and dried for use in herbal teas. As the seasons transition, move the container indoors before nighttime temperatures consistently drop below 50°F.
The plant’s growth will naturally slow during the low-light winter months, entering a semi-dormant state. Adjust your care regimen by significantly reducing the frequency of watering, allowing the soil to dry out slightly more between applications. Stop all fertilizer applications until the return of brighter, longer days in the spring. Some browning of the leaf tips is a normal sign of this resting period.