How to Grow Lemongrass Indoors

Lemongrass grows best indoors in a 5-gallon or larger container with 6–8 hours of direct sun daily or a full-spectrum grow light running 14–16 hours. A single grocery store stalk with an intact root base propagates into a harvestable plant in 3–4 months. Give it warmth above 60°F, well-draining soil, and consistent watering, and it will produce fragrant, harvestable stalks year-round without bolting or going to seed.

Lemongrass (Cymbopogon citratus) is a tropical grass native to Southeast Asia that earns its space indoors through both culinary utility and ease of propagation. A bunch at the grocery store costs $3–5 and is often wilted or woody by the time you use it. A pot of indoor lemongrass provides fresh, tender stalks on demand for Thai curries, Vietnamese pho, herbal tea, marinades, and cocktails — and the cost of setup is recovered within a few months of avoiding grocery store purchases.

Is growing lemongrass indoors worth it?

For anyone who cooks Southeast Asian food regularly, indoor lemongrass is genuinely practical. Unlike many herbs, lemongrass does not lose much flavor when dried, but fresh stalks have a brighter, more aromatic citrus character that dried or frozen lemongrass cannot fully replicate. The lower half of the stalk — the swollen white base that most recipes call for — is the part that is hardest to find fresh in grocery stores and most expensive when available.

The economics are straightforward. A four-pack of lemongrass stalks costs $3–5 at most grocery stores and provides enough for 1–2 recipes. A single pot of indoor lemongrass started from a grocery store stalk costs $10–20 in supplies and begins producing harvestable stalks in 3–4 months. From that point, it provides continuous harvests for months without additional cost, and the clump can be divided to create new plants for free.

Lemongrass also doubles as an ornamental plant. The arching, blue-green blades reaching 2–3 feet high in a pot make it a striking statement plant in a bright room or near a large south-facing window. It performs the same visual function as an ornamental grass while being fully productive.

What you need to grow lemongrass indoors

Step 1: Start from a grocery store stalk

The easiest and cheapest way to grow indoor lemongrass is to start from fresh stalks purchased at a grocery store or Asian market. This method costs almost nothing and has a high success rate as long as you select the right stalks.

What to look for at the store: Choose stalks that have the base attached — the lowest 1–2 inches of swollen white or light green material at the bottom of each stalk. This is the section where roots emerge. Stalks that have been trimmed flush at the base with no rooting zone will not propagate. Stalks from Asian grocery stores are more likely to have intact bases than those pre-packaged at mainstream supermarkets.

The rooting process:

1. Trim any dry, brown outer leaves from the base of the stalk.
2. Cut the stalk down to 6–8 inches from the base, removing the upper green portion (you can use those leaves for tea while you wait).
3. Place the base of the stalk in 2–3 inches of water in a glass or jar, with the lower inch submerged.
4. Set in a warm, bright location — a south window or near a grow light.
5. Change the water every 2–3 days to prevent stagnation.
6. Roots appear in 10–21 days, emerging from the base as thin white threads.
7. Once roots are 1–2 inches long, the stalk is ready to pot.

Alternative — purchase a live plant: Nurseries in warm climates and many online plant sellers carry lemongrass transplants in 4-inch or 1-gallon pots. A transplant is faster — it skips the rooting phase and begins establishing in your final container immediately. This is the better choice if you want harvestable stalks sooner than 3 months.

Starting multiple stalks: Starting 3–5 stalks simultaneously and potting them together into a single 5-gallon container produces a more productive clump faster than a single stalk. Grocery stores often sell bundles of 3–5 stalks, and you can root all of them for the cost of one bunch.

Step 2: Choose the right container and soil

Container choice is more important for lemongrass than for most indoor herbs because of the plant’s vigorous root system and eventual size. Getting this right from the start prevents the most common indoor lemongrass problems: nutrient deficiency, stunted growth, and root-bound stalk thinning.

Container size: Start rooted stalks in a 1-gallon pot for 4–6 weeks, then transplant into a 5-gallon container once the plant shows active new growth. Going directly to a 5-gallon container from a single rooted stalk can lead to overwatering because the large volume of soil stays wet far longer than a small root system can process. The two-step sizing approach gives the roots a chance to fill a smaller container before moving to the final growing size.

For multiple stalks planted together, pot 3–5 rooted stalks directly into a 5-gallon container, spacing them 3–4 inches apart. The combined root system fills the container more quickly and the resulting clump produces more and thicker harvestable stalks.

Drainage: This cannot be overemphasized for container lemongrass. Dense root clumps restrict drainage through soil over time. Choose a container with multiple drainage holes — at least 3–4 for a 5-gallon container — and elevate the pot slightly on pot feet or a plant stand to prevent drainage holes from clogging against a solid surface.

Soil mix: A standard potting mix amended with 20–25% perlite provides good drainage while retaining enough moisture to support lemongrass between waterings. Avoid heavy garden soil or moisture-retaining mixes formulated for water-sensitive plants — lemongrass prefers consistently moist but never saturated conditions.

Step 3: Provide the right light

Light is the most important growing variable for indoor lemongrass, and insufficient light is the most common reason indoor plants produce thin, weak, low-aroma stalks instead of the thick, fragrant ones you find in the produce section.

Window growing: Lemongrass needs a south-facing window for successful indoor growing in northern latitudes. A south window providing 6–8 hours of direct sun daily in summer produces good results from spring through early autumn. East- or west-facing windows provide insufficient total daily light for thick stalk production — plants survive but grow slowly and produce thin, spindly stalks.

In winter, even a south-facing window drops to 4–5 hours of weak sun at northern latitudes. Supplemental grow lighting during winter months significantly improves winter productivity.

Under a grow light: Lemongrass requires more light intensity than leafy herbs like mint or basil. A dedicated grow light with at least 150–200W of actual power draw, positioned 12–18 inches above the plant canopy, running 14–16 hours daily provides adequate intensity year-round. Standard clip-on grow lights designed for small herbs (15–25W) do not deliver sufficient photon density for lemongrass — plants grow slowly and produce aesthetically nice but thin stalks.

Signs of insufficient light: Thin stalks less than pencil diameter after 4 months of growth; pale yellow-green rather than blue-green leaf color; leaves that lean strongly in one direction rather than arching naturally; very slow new stalk emergence. If you see these signs, move the plant to a brighter location or upgrade the grow light.

Temperature: As a tropical grass, lemongrass performs best at 65–85°F. Below 50°F, growth stops and the plant may begin to die back. Never place a lemongrass pot against a cold window on winter nights — the root zone temperature matters as much as the air temperature. Moving the pot 12–18 inches away from window glass in winter prevents cold damage.

Step 4: Water and fertilize for maximum growth

Lemongrass in a container needs consistent moisture but not saturation. The watering approach is similar to other large tropical container plants — water deeply, allow partial drying, repeat.

Watering technique: Water thoroughly until the water runs from all drainage holes. In a 5-gallon container at 70°F with adequate drainage, this typically happens every 3–5 days in summer. Press a finger 2 inches into the soil — water when that depth feels barely moist. In winter with reduced light and lower temperatures, every 5–7 days is typical.

Overwatering signs: The most common mistake. Outer leaves yellow from the base upward; stalks feel soft at the base rather than firm; a sour or rotting odor from the soil surface. If you see these signs, allow the container to dry significantly, check drainage holes for blockage, and increase the perlite ratio in the soil at the next repotting.

Underwatering signs: Leaf tips turn brown and dry; leaves curl inward along their length; the container feels very lightweight. Lemongrass recovers from underwatering quickly after thorough rewatering — within 24 hours the plant typically returns to normal.

Fertilizing: Lemongrass is a grass and grows rapidly — it depletes container nutrients faster than slower-growing herbs. Begin fertilizing 4–6 weeks after potting, once the initial potting mix nutrients are depleted. Apply a balanced liquid fertilizer (10-10-10 or 5-5-5) at half the label strength every 2–3 weeks from spring through early autumn. Reduce to monthly or suspend entirely in winter when growth slows.

Nitrogen is the most important macronutrient for grass growth. If stalks are growing well but appear pale or yellow-green rather than deep blue-green, increase nitrogen slightly by applying a slightly higher-nitrogen fertilizer (such as 15-5-10) or increasing feeding frequency.

Step 5: Harvest lemongrass correctly

Harvesting technique matters for lemongrass because the plant produces new stalks continuously from the center of the clump — harvesting correctly keeps that process going while poor technique can damage the crown or remove stalks that are not yet mature.

When to harvest: A harvestable stalk is at least 12 inches tall and has a base diameter of at least 1/2 inch (roughly pencil thickness). Thinner stalks are not yet mature and removing them slows overall clump productivity. A well-established plant in a 5-gallon container with adequate light produces 2–4 harvestable stalks per month in good growing conditions.

How to harvest:

1. Identify an outer stalk that meets the size requirement.
2. Grasp the stalk firmly at the base, as close to soil level as possible.
3. Twist and pull firmly to snap the stalk cleanly from the crown, or use a sharp knife to cut at soil level.
4. Remove any dry, papery outer leaves — the usable part is the inner stalks, especially the white-to-light-green lower 4–6 inches.
5. Trim the upper green leaf portion to 6–8 inches and use or store.
6. Never harvest more than one-third of the total stalks at one time.

Using harvested lemongrass: The lower 4–6 inches of the stalk is the part used in cooking — bruise or slice it to release the aromatic oils. The upper green leaves are still flavorful for teas and infusions, though more fibrous than the base. Store harvested stalks wrapped in a damp paper towel in the refrigerator for up to 2 weeks, or freeze the trimmed base sections for up to 6 months.

Leaving inner stalks: The center of the clump always contains new, immature stalks developing. Never remove these — they are the plant’s future production. Harvest only from the outermost ring of mature stalks, preserving the inner growth to reach maturity for the next harvest cycle.

Step 6: Overwinter and manage year-round

Lemongrass is perennial in USDA zones 10–11 but frost-sensitive everywhere else. For indoor growers, this is good news: the plant lives year-round in a pot and is never lost to winter, but it does require active management when outdoor temperatures drop.

Moving the plant indoors: If you move your lemongrass outdoors in summer for maximum sun exposure, bring it inside before nighttime temperatures drop below 50°F. In most US climates, this means mid-September to October. Do not wait for first frost — cold damage to the root zone can kill the plant even if temperatures do not drop to freezing.

Winter indoor management: Reduce watering frequency and suspend fertilizing from November through February. Lemongrass in reduced winter light enters a semi-dormant state, growing very slowly. Stalks may dry out and die back — this is normal. Cut dead outer stalks at the base to keep the pot tidy and allow the inner stalks to remain dormant.

Resuming growth in spring: As day length increases after the winter solstice, resume regular watering and fertilizing. Move the pot to the brightest available location or increase grow light duration. New stalks emerge from the crown within 2–4 weeks of resuming full feeding and light. By late spring, the plant is typically in full productive growth again.

Dividing an overgrown clump: After 18–24 months, a lemongrass clump in a 5-gallon container may become root-bound, with stalks growing very close together and root density limiting soil moisture penetration. At that point, remove the entire clump from its container in early spring. Use a sharp knife or garden saw to divide the root ball into 2–3 sections, each containing several stalks with attached roots. Replant each division in a fresh 5-gallon container with new potting mix. This gives you multiple productive plants at no cost.

Troubleshooting common indoor lemongrass problems

Thin, weak stalks despite regular growth — insufficient light. Lemongrass requires high light intensity to build thick, dense stalks. Move to a south-facing window or upgrade to a high-output grow light (150–200W real power). Thin stalks are still usable but will not have the yield of grocery-store quality lemongrass.

Yellowing leaves from the outer ring — normal aging as outer stalks mature. If yellowing spreads to inner stalks or is accompanied by soft, mushy bases, check for overwatering. Improve drainage and allow the container to dry more thoroughly between waterings.

No new stalks emerging after 4-6 months — check root-bound status by examining drainage holes. If roots are dense and emerging from holes, repot into a larger container with fresh soil and resume regular fertilizing. Also check whether the plant is receiving adequate light — new stalk emergence requires higher light intensity than maintenance of existing stalks.

Brown leaf tips — the most common cosmetic issue, caused by low humidity indoors. Lemongrass tolerates this well and it does not affect the culinary quality of harvested stalks. If appearance matters, increase ambient humidity near the pot or mist the leaves occasionally.

Spider mites in winter — the most common indoor pest for lemongrass, encouraged by dry indoor heating air. Rinse leaves thoroughly and apply neem oil solution to all leaf surfaces. Increase ambient humidity to discourage re-infestation.

FAQ

Bottom line

Lemongrass is one of the few tropical herbs that genuinely earns its space as a year-round indoor container plant. The combination of ornamental value, culinary utility, and remarkably easy propagation from grocery store stalks makes it accessible for any indoor gardener willing to provide strong light and a large enough container.

The three factors that determine success: bright light (a south window or a high-output grow light), a 5-gallon container that does not restrict the root system, and consistent fertilizing every 2–3 weeks during the growing season. Get those three right, and a single rooted stalk produces a productive, attractive clump within one growing season that provides fresh stalks for years with minimal maintenance.

Start with 3–5 grocery store stalks set in water this week, and in 3–4 months you will have a harvestable lemongrass clump that eliminates the need to buy bundles at the store before every recipe calling for it.

For more indoor herb growing: how to grow herbs indoors covers the full range of culinary herbs with setup advice for each, how to grow ginger indoors for a similar tropical rhizome that pairs with lemongrass in Southeast Asian recipes, herbs for indoor garden to help choose which herbs suit your light conditions best, and best indoor herb gardens for countertop hydroponic systems that automate growing for a full herb collection.