Lemongrass won’t overwinter outdoors but can go dormant inside
Question: I’m growing lemongrass in a pot for the first time this year. The plant is huge and has many stalks. My questions are: How and when do I harvest it? And will it survive the winter?
Answer: Lemongrass (Cymbopogon citratus) is a staple ingredient in many Asian dishes, and as you discovered, it’s very easy to grow. This tropical, fast-growing plant’s lemony flavor comes from a combination of plant oils.
I grow several lemongrass plants in containers on my patio every summer. They quickly fill the pots and look quite lovely all summer long, making the plant not only appreciated in the kitchen, but also in the garden. It might seem hard to believe, but plants that start as a single blade of grass in early spring are a foot or more wide by season’s end.
Because it will not survive the winter outdoors here in Western Pennsylvania, most gardeners harvest their lemongrass stalks as-needed as the plant grows throughout the summer, rather than waiting for the end of the season to harvest the entire plant.
To harvest lemongrass, pull an individual stalk out of the ground from around the outer edge of the clump. Bending it down toward the soil is often enough to snap it off the mother plant just where it meets the ground. Harvesting individual stalks in this manner allows the rest of the plant to grow undisturbed.
After it’s removed from the mother plant, strip the outer leaves from the stalk. The soft, cream-colored inner stem is the portion of the plant that’s used in recipes. It’s most often sliced open and rinsed with clean water before use to remove any soil wedged in between the layers of the leaf.
Lemongrass stalks are woody, so they’re almost always removed from the dish before being served. The lemony flavor they leave behind, however, is unmistakable. Use the stalks to flavor stir-fries, curries, soups, chicken and fish dishes.
When the danger of frost threatens the garden in the fall, you can either harvest and use any remaining stalks and toss the rest of the plant on the compost pile, or you can try to overwinter it in a dormant state. I often buy new plants every season because they’re inexpensive and they grow fairly quickly, but I have had success overwintering lemongrass in my garage.
To do this, cut the plant back to half its total height when nighttime temperatures regularly dip into the high 40s. Stop watering and move the plant into an unheated garage or a root cellar with a small window. Keep it in a poorly lit area, but not complete darkness. Do not allow the plant to freeze, but protect it from warm temperatures that could encourage it to generate new growth.
Water your dormant lemongrass only once every six to eight weeks throughout the winter. When early April arrives, start watering the plant regularly again and gradually increase the amount of sunlight it receives. By mid-April, start setting it outside on warm days, but take it back indoors at night.
When the plant is acclimated to outdoor conditions and the danger of frost has passed, your lemongrass can go back into the garden.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control” and “Good Bug, Bad Bug.” Her website is jessicawalliser.com.
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