How to Grow Lemongrass: A Toronto Master Gardeners Guide

Lemongrass (Cymbopogon citratus). The bulbous stems of this aromatic tropical grass are used often in Thai and Vietnamese cooking. Lemongrass cannot tolerate frost so it is either grown as an annual outdoors or in a container that can be moved indoors in winter.

Cultivation: Lemongrass grows easily from the green stalks that can be purchased at the grocer. Look for stalks with an intact root plate at the base. Roots will form within two or three weeks in regular potting soil. Alternatively, grow from seeds sown indoors in late winter and maintained at 21°C. Move plants into the garden once night temperatures are reliably over 10°C. Plant in full sun with rich well-drained soil or into a container.

Lemongrass grows rapidly in hot weather, reaching 60 to 90 centimeters tall, and may need repotting and/or dividing during the summer. Keep plants well-watered to maintain moist but not soggy soil. Fertilize about every two weeks with a general-purpose fertilizer or top dress with compost.

To keep lemongrass over the winter, move it indoors as soon as night temperatures are sinking to 10°C. Cut the plant back and place it in a cool (5°C) dark spot, where it will go dormant, or maintain it in a sunny position as a houseplant. When overwintering indoors, water as needed and reduce the frequency of fertilizer application.

Stalks at least 1½ centimeters thick can be harvested at any time and frequent harvesting will encourage new growth. To harvest, cut stems, trim off and discard the leaves, and retain the bottom eight to ten centimeters for use. Alternatively, remove the entire plant from its pot, remove a section by cutting through the root ball with a sharp knife, and repot the remaining root ball. Store the stems that have been removed in the fridge or freeze them for future use.

Disclaimer: Toronto Master Gardeners does not advise or recommend herbs for medicinal or health use. Any information in the recommended resources should be regarded as being for educational purposes only and should not be considered as a recommendation or an endorsement of any medical or health treatment.

 For more information:

The Prairie Homesteader https://www.theprairiehomestead.com/2014/11/lemongrass-grow-use.html

West Coast Seeds https://www.westcoastseeds.com/blogs/how-to-grow/grow-lemongrass

RHS Grow-You- Own-Herbs: Lemongrass https://www.rhs.org.uk/advice/grow-your-own/herbs/lemongrass

University of Wisconsin-Madison, Wisconsin Horticulture Division of Extension: https://hort.extension.wisc.edu/articles/lemongrass/

University of Illinois Extension  https://web.extension.illinois.edu/herbs/lemon-grass.cfm

Gardening Know How https://www.gardeningknowhow.com/edible/herbs/lemongrass/growing-lemongrass-indoors.htm

Date revised: December 2021

Prepared by the Toronto Master Gardeners, these Gardening Guides provide introductory information on a variety of gardening topics.  Toronto Master Gardeners are part of a large, international volunteer community committed to providing the public with horticultural information, education and inspiration.  Our goal is to help Toronto residents use safe, effective, proven and sustainable horticultural practices to create gardens, landscapes and communities that are both vibrant and healthy.

Statement on Invasive Plants: When choosing plants, avoid invasive plants, which can spread quickly and dominate gardens.  Invasive plants are sold by nurseries, big box stores or even at community plant sales.  Invasives may already be present in your garden.  They can invade gardens by spreading from under a neighbour’s fence or may be transported by wildlife.  For beautiful, sustainable options to invasive plants, see the Ontario Invasive Plant Council’s “Grow Me Instead – Beautiful Non-Invasive Plants for your Garden” at https://www.ontarioinvasiveplants.ca/resources/grow-me-instead/before purchasing or accepting “gifts” of plants.

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