How to grow lemongrass indoors

Lemongrass is a tropical grass native to Asia, Africa, and Australia, grown for the citrus flavor concentrated in the pale base of its stalks. It turns up in Thai and Vietnamese cooking, in teas, and in traditional medicine.

It is one of the easier herbs to grow indoors, largely because it wants exactly what a heated house already provides: warmth. It also regrows after cutting, so a single pot keeps producing for years.

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.

Best light conditions

Lemongrass grows in full sun in its native range, and it needs as close to that as you can manage indoors.

• South-facing window: If you’re growing lemongrass in your home, positioning it by a south-facing window is ideal. This location typically receives the most sunlight throughout the day.
• Duration: Ensure that your lemongrass receives a minimum of 6-8 hours of sunlight daily.
• Grow lights: For areas where natural sunlight is limited, especially during winter months, consider using indoor grow lights. These lights can supplement or even replace natural sunlight, ensuring your lemongrass gets the illumination it needs.

Temperature requirements

Remember, lemongrass is a tropical plant. It’s used to warm conditions and can be sensitive to cold.

• Ideal temperature: Aim to maintain an indoor temperature above 70℉ for your lemongrass. This warmth mimics the tropical climates the plant is accustomed to.
• Avoiding the cold: Lemongrass can’t handle temperatures below 50℉. Ensure your plant isn’t near drafty windows or doors, especially during cooler months.

Light and warmth are the two conditions that decide whether indoor lemongrass produces usable stalks or just sits there. Everything below matters less.

Other conditions

1. Soil type and pH level: Lemongrass prefers well-draining soil. Heavy soils can cause root rot, so it’s essential to ensure the soil drains excess water effectively. While lemongrass isn’t overly fussy about soil pH, it generally prefers a slightly acidic to neutral pH range (6.0 to 7.5).

2. Humidity: Being a tropical plant, lemongrass prefers a humid environment. While it can tolerate drier indoor air, you might notice improved growth if you can increase humidity around the plant. This can be achieved by misting the plant occasionally, placing the pot on a tray of wet pebbles, or using a humidifier in the room.

3. Air circulation: Good air circulation helps prevent fungal diseases. Make sure the indoor area isn’t stuffy and allows for some movement of air. This can be achieved by occasionally running an oscillating fan or ensuring that the room has regular airflow.

4. Water quality: Lemongrass prefers chlorine-free water. If your tap water is treated with chlorine, consider leaving it out for 24 hours before watering or use filtered water.

5. Spacing: If you’re growing multiple lemongrass plants in one container or in separate pots nearby, ensure they have adequate space to grow. Crowding can reduce airflow and light access, which can affect their health.

None of these will make or break the plant on their own, and together they account for most of the difference between a lemongrass that survives and one that fills its pot.

Necessary supplies for indoor lemongrass cultivation

Picking the perfect pot

Lemongrass grows in clumps that spread sideways, so width matters more than depth. A 12-inch pot gives a plant room to fill out over a couple of years before it needs dividing. We recommend this ceramic 12-inch pot from Fox & Fern.

A 6-inch pot is fine to start in, and expect to repot within a season as the clump widens. Snag a four-pack of terracotta 6-inch pots here.

Coconut coir or potting soil

The growing medium is the one real decision to make before planting.

Coconut coir is the fibrous outer husk of coconuts, sold compressed into bricks that you rehydrate.

Pros of coconut coir	Cons of coconut coir
Airy structure: Excellent for root growth.	Nutrient lack: Needs frequent fertilizing.
Moisture retention: Holds water without waterlogging.	Price: Can be pricier than potting soil.
Eco-friendly: A sustainable option.

Regular potting soil has been the go-to for indoor gardeners for years.

Pros of potting soil	Cons of potting soil
Nutrient-rich: Good initial feed for plants.	Moisture retention: Can sometimes be excessive.
Versatility: Suitable for most indoor plants.	Consistency: Quality varies between brands.

For a first attempt, start with coconut coir. It is forgiving if you water inconsistently and its open structure suits lemongrass roots. The tradeoff is that coir carries almost no nutrients of its own, so you will need to feed more regularly than you would in potting soil. Coco Bliss is a good brand.

Sources for lemongrass: cuttings vs. seeds

Starting with cuttings is the most popular method. It’s quicker and often yields better results. Look for green, healthy stalks and plant them an inch deep into the substrate.

Alternatively, seeds can be used but they might take longer to germinate. If you opt for seeds, make sure they are fresh and from a reputable supplier.

Steps to plant lemongrass

Prepare and fill container

The first step is all about getting your pot ready.

Grab your clean, sterilized container. Fill it up with your chosen growing media (either coconut coir or potting soil) until there’s about an inch of space left at the top.

As you fill your pot, give the media a gentle press to get rid of any air pockets. This spreads the substrate evenly and stops it settling into a gap below the rim over the following weeks.

Plant rooted stalks or sow seeds

If you’ve got lemongrass stalks that you’ve rooted in water or if you’ve bought pre-rooted ones online, you’re in a good place. Plant these stalks so the bulb’s base is about an inch below the surface. Spread the roots out a bit as you plant; it helps them grow and spread more naturally.

On the other hand, if you’ve got seeds, sprinkle them on top and lightly cover them with a thin layer of your growing media. Seeds need their space too, so if you’re planting directly into the substrate, make sure they’re about 1” apart and ¼” deep.

Lastly, ensure your pots are placed somewhere warm. It’s the kind of environment lemongrass loves and it encourages the best growth and germination.

Optional: grow lemongrass as a microgreen

Lemongrass can also be grown as a flavorful microgreen. Sow the seeds more densely on top of your chosen medium and cover lightly. Keep the soil moist, and in a couple of weeks, you’ll have a tray of fragrant lemongrass microgreens ready for harvest. They’re perfect for garnishing and adding a burst of flavor to salads and dishes.

Interested in learning more about microgreens? Check out our comprehensive microgreens guide.

Care tips for lemongrass

Watering guidelines

Lemongrass likes to be kept moist without being wet. Check the top inch of the soil or coconut coir; if it feels dry, it’s time to water.

Creating a warm environment

For the best growth and germination, place your pots somewhere that consistently stays above 70°F (21°C). In a cold region or in mid-winter, a seedling heat mat under the pot makes the difference.

Importance of nitrogen in fertilization

Lemongrass is a grass, and like most grasses it needs a good amount of nitrogen to put out green growth.^[1] Consider adding a balanced liquid fertilizer with a slightly higher first number (indicating nitrogen content) to nourish your plant every 2–3 weeks. If you have it on hand, compost will also work.

Want to learn more about fertilizing lemongrass and other herbs? Check out our beginner-friendly guide.

Regular harvesting for fresh growth

Trimming the older stalks encourages new ones from the base. Regular cutting keeps the clump productive rather than letting it run to a mass of tough, woody stems.

Managing plant overcrowding

As your lemongrass grows, it might start to feel a little crowded in its pot. This can stunt growth. Make sure to either divide the plant or transfer it to a bigger container if things get too tight.

Harvesting lemongrass

When to harvest

Lemongrass matures relatively quickly, and you can start harvesting as soon as 3-4 months after planting. Look for stalks that are about 12 inches tall and have developed a firm base. Remember, young stalks are tender and flavorful, but even the mature ones bring a strong taste to dishes.

How to harvest

Harvesting lemongrass is a simple task. Grasp the stalk near its base and either twist it or cut it using a sharp knife or gardening shears. Make sure you don’t pull too hard, or you might uproot the entire plant.

Using the bottom of the stalk

Most recipes call for the bottom few inches of the stalk, where the flavor is concentrated. Peel off the outer leaves until you reach the pale-yellow inner core, then slice it finely or crush it with the flat of a knife. The tough green tops are too fibrous to eat, and they are good for infusing broths, soups and teas if you fish them out before serving.

Questions & answers

How often should I water my indoor lemongrass plant?

Keep the soil or coconut coir consistently moist without being wet. Water when the top inch of the substrate feels dry to the touch.

My lemongrass leaves are turning brown. What's wrong?

Brown leaves can be a sign of several issues, including overwatering, underwatering, or low humidity. Make sure you’re providing the right amount of water and consider increasing humidity levels around the plant.

Can I propagate lemongrass from grocery store stalks?

Yes, and it is the cheapest way to start. Buy fresh stalks with a portion of the base still intact. Place them in a jar with an inch or two of water. In a few weeks, they should develop roots, and you can plant them in soil or coconut coir.

Do I need to repot my lemongrass regularly?

If your lemongrass becomes root-bound or overcrowded in its current pot, it’s a good idea to either divide the plant or move it to a larger container.

How do I know if my lemongrass is receiving enough light?

If your lemongrass is not getting sufficient light, it may become leggy, with tall, thin stalks stretching toward the light source. Ensure it’s getting a minimum of 6-8 hours of sunlight or equivalent grow light exposure.

Can I grow lemongrass outdoors during summer?

Yes, and it will grow faster outdoors than in. Move it out once nights stay above 50°F, and acclimatize it over a week or two in partial shade first, since foliage grown under glass scorches in direct sun.

References

1. 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. ↩︎