How to grow lemongrass indoors

Native to Asia, Africa, and Australia, lemongrass is a tropical herb known for its citrusy flavor. It is used worldwide in various ways, most commonly for the delicate lemon flavor the tender shoots and leaves impart into culinary dishes.

Lemongrass is surprisingly easy to propagate and grow in containers indoors, continuously regenerating new shoots and leaves after being harvested for use.

Common uses for lemongrass

Lemongrass is a versatile plant, lending itself to many applications:

  • As a flavoring in Asian cuisine, primarily Thai and Vietnamese recipes.
  • Brewed into a tea.
  • In India, the plant is made into an ayurvedic drink called khadha, regarded for its medicinal and healing properties.
  • Plants are grown as ornamental grasses, creating privacy screens due to their mature size.
  • Citronella oil found in lemongrass plants acts as a natural mosquito and whitefly repellent.

Indoor growing conditions

Lemongrass is native to tropical regions of Asia, Africa, and Australia; due to this, plants prefer sunny, hot growing conditions, making lemongrass well suited for growing indoors.

Plants thrive in full-sun conditions. When growing indoors place containers in a south-facing window if possible where they can receive a minimum of 6-8 hours of sunlight daily. If necessary, supplement sunlight with indoor growing lights.

In terms of temperature, lemongrass cannot handle air temperatures that drop below 50℉ and prefer soil temperatures above 70℉. Keep containers away from cold air or drafts coming in through doors and windows.

Supplies needed for growing lemongrass indoors

If you already grow plants indoors, you’re well on your way to having the supplies you need to grow lemongrass.

Containers

Mature lemongrass plants can grow up to 5’ tall if left unharvested. Choose deep containers so plants don’t tip over. Containers at least 12” wide will allow plants to self-propagate better than other small pots.

Growing substrate

Coconut coir and potting soil are two of the most common options for growing media when growing plants in containers. Coconut coir is composed of the brown and white fibers found between the shell and the outer coating of a coconut seed and retains moisture well. Potting soil is a combination of “soilless” materials: peat moss or coconut coir, pine bark, perlite, and vermiculite; potting soils are lightweight and have good water and nutrient holding capacity.

Plants or seeds

Lemongrass is grown by either propagating cuttings from existing plants or starting new plants from seed.

Growing lemongrass from cuttings is the preferred method of starting new plants.

An easy way to accomplish this is to purchase intact stalks from the grocery store – you may need to visit a local Asian market to find lemongrass – and root cuttings from the lemongrass stalks. Remove the lower leaves to expose the bulb and then place in a glass or jar containing fresh water. Change the water daily until roots form. If lemongrass isn’t available locally, pre-rooted specimens are available online through various retailers.

Growing lemongrass by germinating seeds is possible but presents more challenges.

Lemongrass seeds need high humidity and warm temperatures for germination, increasing the incidence of fungal problems when trying to grow from seed. The University of Minnesota Extension explains that seedlings are also prone to damping off, which can decimate most if not all newly germinated plants. Watch seeds carefully as they germinate, monitoring for signs of fungus or disease.

Planting Instructions

Planting lemongrass follows the same basic tenants as other indoor herbs/plants.

  1. Start by filling clean, sterilized containers to within about an inch of the top of the pot with the chosen growing media. Gently tamp down the substrate to eliminate any pockets of air unintentionally created; this prevents the growing media from settling over time.
  2. If you purchased stalks from the market and rooted them in water, or purchased pre-rooted plantlets online, plant the rooted stalks so the base of the bulb is about an inch below the soil/coconut coir surface. Make sure to fan the roots out when planting to encourage their natural growth and spreading.
  3. If planting seeds, sprinkle them on top of the growing substrate and cover them with a scant layer of the chosen media. If sowing them directly into the substrate plant them about 1” apart and ¼” deep.
  4. Place containers in a warm environment to encourage optimal germination or growth.

Caring for your plants

Lemongrass is easy to grow indoors, especially if you heed the following tips:

Keep the growing substrate damp but not overly soggy. Plants need plenty of water but saturated substrates have water filling all of the available pore space, decreasing the oxygen available to roots. Oxygen deficiency affects many metabolic processes within the plant, including respiration and metabolism of nitrogen (Sousa & Sodek, 2002), resulting in decreased plant growth.

Add nitrogen fertilizer or compost every 2-3 weeks to provide a fresh source of nitrogen for the plants. Lemongrass is considered a high nitrogen feeder because of its rapid vegetative growth; nitrogen plays a vital role in biochemical and physiological functions within the plant (Leghari, 2016) and rapid plant growth quickly depletes nitrogen found in the growing substrate of container plants.

Harvest material from the lemongrass plants frequently to encourage new growth.

As your lemongrass plants grow they send out new shoots, creating a new root ball that is dense. Periodically break up this root ball and divide plants to prevent overcrowding.

Harvesting Lemongrass

You can start enjoying fresh lemongrass as soon as your plants are around a foot tall. The lower part of the stalk is the most tender and useable part of the plant, so take care to harvest the bottom of the stalk. The lower portion of the stalk is also used in new lemongrass propagation. 

Growing lemongrass as a microgreen

Like many other herbs, growing lemongrass as a microgreen is rapidly gaining popularity because of its simplicity and rapid time to harvestable plant material. When grown as a microgreen all of the flavors of mature plants are garnered without the woodiness.

To grow lemongrass as a microgreen place sterilized potting soil or coconut coir in shallow containers. Sprinkle lemongrass seeds liberally on top of the growing substrate and cover lightly. Place containers in a warm spot and keep the seeds moist; lemongrass seeds germinate within 1-2 weeks.

Water containers from below, and do not fertilize. Microgreens are ready for harvest when plants have 2-4 leaves.

Conclusion

Known primarily for its role in Asian inspired dishes, lemongrass is easy to grow indoors in containers. It prefers full-sunlight and warmer temperatures, providing plenty of harvestable plant material with little care other than watering and periodic fertilizing. Lemongrass is also quick and easy to grow as a microgreen, delivering the taste of mature foliage in as little as a few weeks. If you choose to grow indoors, you can enjoy fresh lemongrass year round. 

References

Leghari, S. J., Wahocho, N. A., Laghari, G. M., Laghari, A. H., Bhabhan, G. M., Talpur, K. H., Bhutto, A. T., Wahocho, S. A., & Lashari, A. A. (2016). Role of Nitrogen for Plant Growth and Development: A review. Advances in Environmental Biology, 10, 209-218.

Sousa, C. A. F. de, & Sodek, L. (2002). The metabolic response of plants to oxygen deficiency. Brazilian Journal of Plant Physiology, 14(2), 83-94.

Feature Image: Yotoen



Amanda Shiffler

Amanda Shiffler

Most comfortable with soil under her fingernails, Amanda has an enthusiasm for gardening, agriculture, and all things plant related. With an M.S. degree in agriculture and over a decade of experience gardening, she combines her plant knowledge and knack for writing to share what she knows and loves.

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