Lemongrass is a tropical grass that adds incredible flavor to soups, curries, teas and more. Its citrusy aroma and taste simply can’t be duplicated. The good news is lemongrass is easy to grow at home from seed With just a little planning, you can have fresh lemongrass ready to harvest all summer long
When you start lemongrass seeds indoors, you have more control over the growing conditions while they are sprouting. It also lets you move bigger, stronger plants outside when the time is right. Read this whole guide to learn when to plant lemongrass seeds and how to grow seedlings into healthy plants.
Why Start Lemongrass Seeds Indoors?
Here are some of the main benefits of starting lemongrass seeds indoors rather than direct sowing:
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For better germination rates, you can keep the temperature and moisture level steady. Lemongrass seeds need temperatures around 70°F to sprout well.
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When grown indoors, young seedlings are safe from things like heavy rain, wind, animals, and bugs.
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Plants get a head start on the growing season when you start seeds early. Transplants will be larger and more robust.
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You can control factors like sunlight and properly harden off plants before transplanting outdoors.
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There is less wasted seed compared to direct sowing. You can thin and space seedlings properly.
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Weed control and maintenance are easier with containerized plants ready for transplant.
No special equipment is needed. With a sunny window, grow lights or a heating mat you can grow lemongrass indoors anywhere.
When to Sow Lemongrass Seeds
Lemongrass thrives in heat, so timing is important. Count backwards from your last expected spring frost date based on your growing zone.
For zones 3-7:
- Start seeds indoors 12-14 weeks before your projected last frost date.
For zones 8-11:
- Start seeds indoors 8-10 weeks before your average final frost.
You can also direct sow lemongrass outdoors 3-4 weeks before your last expected frost date. Check local frost dates and plant calendars to determine your ideal indoor seed start date.
How to Plant Lemongrass Seeds
Follow these simple steps for starting lemongrass seeds indoors:
Gather Supplies
You’ll need containers, seed starting mix, a tray or dome, labels, and a spray bottle. A seedling heat mat can provide 70°F soil warmth. Full spectrum grow lights are beneficial once sprouted.
Fill Containers
Use cell packs, flats or other small containers with drainage holes. Gently firm moistened seed starting mix into containers.
Sow Seeds
Plant seeds 1/16 inch deep and 1 inch apart. Lemongrass needs light to germinate.
Cover, Mist and Warm
Mist soil, cover trays, place on heat mats. Remove domes once seedlings appear.
Thin Seedlings
Allow the strongest seedling per cell to remain once the 2nd set of leaves appears.
Transplant in 4-6 Weeks
Harden off and transplant outdoors after all chance of frost has passed.
Caring for Lemongrass Seedlings
Proper care during the seedling stage is crucial:
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Provide 14-16 hours of light per day with grow lights.
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Keep soil moist but not saturated to prevent damping off.
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Allow the top inch of soil to dry out between waterings.
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Feed weekly with a balanced liquid fertilizer once sprouted.
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Ensure good air circulation once domes are removed.
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Maintain warm soil temperatures around 70°F until sprouted.
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Support tall, leggy seedlings with plant stakes if needed.
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Harden off seedlings slowly over 7-10 days before transplanting outside.
Transplanting Lemongrass Outdoors
Here are some tips for transplanting lemongrass successfully:
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Harden off seedlings for 7-10 days first. Slowly introduce to outdoor conditions.
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Transplant after all danger of frost has passed and soil is 65°F or warmer.
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Space plants 12-24 inches apart in full sun. Lemongrass reaches 2-4 feet wide at maturity.
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Select a site with well-draining soil. Amend with compost if needed.
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Water transplants daily the first week, then allow soil to dry between waterings.
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Apply a balanced organic fertilizer monthly during the growing season.
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Mulch around plants to retain moisture and reduce weeds.
Ongoing Care of Lemongrass Plants
Here are some tips for keeping your lemongrass looking its best all season:
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Water whenever the top 1-2 inches of soil become dry. Avoid overwatering.
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Fertilize monthly with a balanced organic fertilizer.
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Remove any dead leaves or spent stalks promptly.
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Harvest stalks for use when they reach 1⁄2 inch diameter at the base.
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In fall, prune stalks to 6 inches, dig up roots and overwinter indoors.
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Mulch plants in zones 9-11 in fall for extra frost protection.
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Start seeds again 8-12 weeks before your last spring frost to replace overwintered plants.
Troubleshooting Common Lemongrass Problems
Follow these tips to avoid potential pitfalls:
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Start more seeds than needed in case of low germination rates.
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Ensure warm enough soil temperatures for germination. Use a heat mat.
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Don’t let seeds dry out. They need consistent moisture to sprout.
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Prioritize air circulation and promptly remove domes once sprouted.
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Pinch off top growth to encourage bushier, fuller plants.
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Harvest stalks when 1⁄2 inch wide at the base for optimal flavor.
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Mist leaves regularly to boost humidity. Lemongrass prefers 40-60%.
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In cold climates, overwinter plants in pots near sunny windows indoors.
The Reward of Growing Lemongrass
Now you know exactly when and how to start lemongrass seeds indoors for success. There’s nothing quite like the flavor and fragrance of fresh, homegrown lemongrass. It costs just pennies compared to buying it. With proper planning, you can grow lemongrass year after year. Get your seeds started now for your best harvest yet!
How to grow LEMONGRASS from seed to sprout | How to encourage lemongrass seed to germinate quicker
FAQ
What month is best to plant lemongrass?
Plant seedlings or transplants of lemongrass outside in the spring or fall. Lemongrass6a: After the last frost, on or around April 15; Lemongrass6b: After the last frost, on or around April 15; Lemongrass7a: After the last frost, on or around April 15; Lemongrass7b: After the last frost, on or around April 15
Does lemongrass come back every year?
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Better Homes & Gardenshttps://www.bhg.comIs Lemongrass a Perennial? How to Grow This Flavorful HerbMar 15, 2025 — “Frost-tender” is important to note because although lemongrass is a perennial, the plant is only winter hardy in USDA Zones 10-11 where it’s evergr…
Does lemongrass grow well in pots?
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Portability:Pots allow for easy relocation of the plant to a warmer indoor location during winter months, protecting it from frost.
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Control:Pots offer better control over the soil and watering conditions, which can be advantageous for lemongrass.
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Space efficiency:Pots are ideal for smaller gardens or patios, allowing you to grow lemongrass even with limited space.
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Easy to manage:Pots can be moved to maximize sunlight exposure and protect the plant from wind or excessive rain.
How do you grow lemongrass from seed?
To grow lemongrass from seed: Choose a location with well-drained soil and a pH of 6. 5 to 7 in either full sun or part-shade. Sow the seeds 1/8 of an inch (5mm) deep with a spacing of 12 inches (30cm). Water well. The seeds should start to germinate within 10 to 14 days. Thin out the seedlings so that you have 1 plant every 12 inches (30cm).
When should I start lemongrass seeds indoors?
You’ll need to have a few tools and materials, but you likely have many of them already. Start lemongrass seeds indoors three weeks before the last frost. When starting seeds indoors, it’s important to get the timing right. You want to start seeds about three weeks before your average last frost date.
Can you plant lemongrass indoors?
Wait until danger of frost has passed before planting lemongrass, preferably once nighttime temperatures consistently hit 60 degrees. To start from seed indoors, sow in flats three weeks before the last frost in your growing zone. Choose a spot in full sun with good drainage. Lemongrass won’t grow well in clay and needs rich, fertile, loose soil.
When should I start germination of lemongrass?
Since lemongrass is an annual herb it requires little attention throughout the growing season. The main concern is germination. Germination is important because lemongrass needs support to grow properly. When growing lemongrass from seed, the best time to start germination is 2 to 5 weeks prior to the last frost.
How long does lemongrass take to grow?
And the germination rate of lemongrass is low at around 50%. It’s best to sprinkle several seeds into each pot, then thin them out once they emerge. The seeds should germinate within 10-14 days. When they have an inch or so of growth, thin to just a few plants per cell or pot.
What temperature do lemongrass seeds need to germinate?
Lemongrass seeds require a minimum temperature of 68°-70° Fahrenheit (20°-21° Celsius) to germinate. It’s also important to keep the seed starting medium evenly moist but not soaked in water while you wait for the seeds to sprout. Another important note is that lemongrass seeds need light to germinate.