Grow Lemongrass in Pots Year-Round: The Overwintering Trick That Saves Your Plants Each Fall
Container lemongrass thrives with the right overwintering strategy. Discover the 50°F rule and two methods that keep your plant alive through winter.
Lemongrass fills a pot from May through October—stalks building into thick clumps, fragrance rising every time you brush past—then dies the first October frost because most gardeners don’t know when or how to move it indoors. Container growing is the permanent fix: you control when winter begins and ends. And because Cymbopogon citratus grows in dense clumps from underground rhizomes rather than spreading roots, a pot concentrates that vigor rather than constraining it.
This guide covers the full year: choosing containers and potting mix, dialing in summer care, and—most critically—the fall transition and two overwintering strategies that determine whether your plant makes it to spring. For foundational lemongrass care, see our complete lemongrass growing guide.
Why Container Growing Works So Well
Lemongrass is native to tropical Asia and is reliably perennial only in USDA zones 9–11, where temperatures rarely approach freezing. Everywhere else, it’s the portability of container growing—not any special hardiness trick—that keeps plants alive year after year.
The plant’s growth habit makes this particularly efficient. Lemongrass spreads by producing tillers—new shoots that emerge from the central rhizome—rather than sending out long lateral runners [5]. A 12-inch pot captures this clumping growth without wasting it. You lose nothing compared to in-ground growing during the warm months, and you gain everything when autumn arrives.
The cold sensitivity has a precise biological cause that explains why timing matters so much. Lemongrass, like other tropical grasses, suffers chilling injury once temperatures approach 40°F (4°C). At that threshold, the lipid membranes in plant cells lose fluidity and can no longer regulate ion transport properly. Chloroplast function slows, ATP production drops, and within days the foliage browns and stalks collapse. This isn’t frost damage—it begins a full ten degrees above freezing, which is why a cool, dry garage is far safer than an unheated porch.
Choosing the Right Container
Start with a pot at least 12 inches across and 12–18 inches deep, or use a 5-gallon bucket [8]. Undersized containers lead to rootbound plants, cracked pots, and dramatically reduced yields by midsummer. If you’re dividing a mature plant—which becomes necessary every one to two years—give each division its own 12-inch container and it will fill that space by August.
Material matters most at overwintering time, when you’re moving the plant across your home for several months:
| Material | Summer Performance | Winter Suitability |
|---|---|---|
| Plastic | Retains moisture well; lightweight to move | Best for overwintering—easy to carry, won’t crack in cold |
| Glazed ceramic | Attractive; durable; holds moisture evenly | Fine indoors; heavier but doesn’t dry out as fast as terracotta |
| Terracotta | Good drainage; breathable walls | Avoid for indoor overwintering—dries out fast and can crack if left cold |
Whatever the material, drainage holes are non-negotiable. Multiple small holes across the base outperform a single central one. For more on setting up containers for success, see our handbook for container gardening.
Repot every one to two years in fall, just before moving indoors, when the plant has finished its growing year [9]. Lemongrass becomes especially rootbound over time; you may need a serrated knife to split the root ball into two or three sections, each with roots and a cluster of stalks.
The Ideal Potting Mix
Standard potting soil alone compacts too densely for lemongrass in containers—it holds moisture unevenly and suffocates roots during wet winters. A reliable recipe:
- 60% quality peat-free potting compost — organic base and initial nutrition
- 30% perlite — improves drainage and keeps the mix aerated between waterings
- 10% aged compost or bark — slow-release nutrition and biological activity
This ratio matches RHS guidance for lemongrass containers [1] and keeps the mix loose and fast-draining even after months of use. Target pH 6.5–7.0 [8]—lemongrass is tolerant of a modest range but turns yellow below 6.0. For more on choosing potting mixes for containers, our guide covers ratios across common herbs and edibles.
Each spring, remove the top 2–3 inches of old mix and replace with fresh compost. This replenishes nutrients that leach out over the growing season without requiring a full repot.
Light and Temperature by Season
Outdoors, lemongrass needs full sun—at least 6 hours of direct light daily, with 8+ hours producing the densest stalks and strongest citrus fragrance. In partial shade, growth turns spindly and harvests thin noticeably.
The ideal growing temperature range is 68–86°F (20–30°C)—the tropical band this grass evolved in. It tolerates brief excursions above 90°F with consistent watering but slows below 55°F even outdoors. The RHS advises keeping lemongrass above 13°C (55°F) for healthy outdoor growth, and above 7°C (45°F) as a bare minimum for survival [1].
Indoors in winter, light requirements differ by method. The active houseplant method needs a south-facing window with 6+ hours of direct light, or 12 hours under a grow light. The dormancy method requires only low indirect light while the plant rests.
Watering Season by Season
Lemongrass is thirsty in summer. Container roots dry out far faster than in-ground plantings, and by August in most US climates a large pot may need watering every one to two days. Push a finger an inch into the soil—if it’s dry, water thoroughly until it drains from the base.
The schedule shifts sharply across the year:
- Spring: consistently moist as growth resumes; once or twice a week while nights are still cool
- Summer: every 1–2 days in heat; never let the soil dry completely
- Fall: reduce to every 3–4 days as growth slows and temperatures drop
- Winter (dormant): once per month—just enough to prevent the roots drying out [6]
- Winter (active houseplant): when the top inch of soil is dry, roughly every 1–2 weeks
Overwatering in winter is the most common killer of container lemongrass. Soggy soil at 55°F invites root rot far faster than in summer warmth.
Feeding Your Container Lemongrass
Containers limit nutrient reserves—water leaches them with every watering cycle. Consistent feeding during the growing season is essential and pays off directly in stalk thickness and harvest quality.
Apply a balanced water-soluble fertilizer (10-10-10 or similar) at half strength weekly from June through early September [2], or full strength every two weeks [4][8]. USU Extension specifically recommends the half-strength weekly approach for container plants: frequent light doses replace what leaches out without building up salts that scorch roots over time.
Add one or two mid-summer nitrogen boosts—a 20-10-10 formulation once per month—to push lush leaf growth during peak season. Stop feeding entirely from September onward; late-season feeding pushes tender new growth that won’t harden before the indoor move. Do not fertilize during winter regardless of method [7]. Resume a half-strength balanced feed in spring once new growth reaches 3 inches.
The Fall Overwintering Decision
This is where most container lemongrass dies—not from neglect, but from a delayed decision. Move your plant indoors when overnight temperatures are forecast to drop below 45–50°F consistently [1][6]. In zones 5–6 that typically means mid-September to early October. In zones 7–8, late October to early November. Don’t wait for the first hard frost—chilling injury begins well above freezing.
Before moving indoors: cut the foliage back to 6–12 inches, inspect the undersides of leaves for spider mites (see our spider mite identification and treatment guide), and repot if the plant is visibly rootbound. Then choose your strategy:
| Method | Conditions Needed | Effort | Winter Harvest |
|---|---|---|---|
| Dormancy (cool-dark) | 50–60°F, low light, garage or basement | Very low | No |
| Active houseplant (bright window) | 60°F+, south window or grow light | Moderate | Yes, lightly |
Dormancy method: Place the cut-back pot in a garage, basement, or cellar kept at 50–60°F [6]. Water once per month—just enough to keep roots from drying out completely. The plant enters a low-activity state with no visible growth and requires almost no attention from November through February. It emerges reliably once warmth returns in spring.
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→ View My Garden CalendarActive houseplant method: Keep the plant in a bright south-facing window above 60°F, or under a grow light for 12 hours per day. Water when the top inch of soil is dry. Growth is slow but continuous, and you can take small harvests through winter. If indoor air is dry from central heating, set the pot on a tray of pebbles and water to raise humidity and deter spider mites. For a deeper look at full-time indoor lemongrass growing, see our guide to growing lemongrass indoors year-round.
Spring Transition: The Hardening-Off Window
Moving overwintered lemongrass directly from a dim basement into full outdoor sun is the fastest way to scorch it. Even plants that spent winter in a bright window need gradual reintroduction to outdoor light intensity.
Begin when daytime temperatures reliably reach 50°F (10°C) [6]:
- Week 1–2: 1–2 hours of morning sun daily, returning to shade or indoors each afternoon
- Week 3: extend outdoor time to 4–5 hours, shifting toward part-sun exposure
- Week 4: move to the final full-sun position and leave outdoors
For dormancy-method plants, expect new growth to reappear 2–3 weeks after consistent warmth once soil temperature rises above 55°F. Resume half-strength balanced fertilizing when new growth reaches 3 inches. Don’t rush the transition—cold shock after an indoor winter is more damaging than the winter itself.
Harvesting from Containers
Container lemongrass harvests the same way as in-ground plants, but the finite clump size means portion control matters. Begin once the plant is at least 12 inches tall with stem bases at least half an inch thick [2][8]. Harvesting too early stunts recovery.
Always take outer stalks first—the central tillers are the plant’s regrowth engine. Twist and pull a stalk at soil level, or cut just above the base. Never remove more than one-third of the plant in a single harvest. A healthy 12-inch container plant typically yields 6–10 harvestable stalks between July and early September.
The lower 4–6 inches of the swollen stem base hold the most concentrated citrus flavor for cooking. Upper leaves work well for teas and infusions. For ideas on using your harvest, see our guide to lemongrass uses in cooking, tea, and beyond.
Troubleshooting Container Lemongrass
| Symptom | Most Likely Cause | Fix |
|---|---|---|
| Brown leaf tips in winter indoors | Low humidity from dry heated air | Add a humidity tray; keep relative humidity above 50% |
| Yellow leaves | Overwatering or poor drainage | Check drainage holes; let soil dry between waterings |
| No spring growth after dormancy | Storage too cold below 40°F; rhizome damaged | Move to a warmer spot above 55°F; water lightly and wait 3–4 weeks |
| Fine webbing on leaves indoors | Spider mites—thrive in hot, dry indoor air below 50% RH | Treat with insecticidal soap [2]; raise humidity above 50% |
| Mushy, dark stem bases | Root rot from waterlogged soil | Repot immediately into fresh draining mix; reduce watering frequency |
| Spindly, pale growth indoors | Insufficient light | Move to south-facing window or add a 12-hour-per-day grow light |
Seasonal Care Calendar
| Month | Key Tasks |
|---|---|
| March | Check dormant plant; resume watering twice monthly as temperatures rise |
| April | Begin hardening off when days reach 50°F; restart half-strength fertilizing with first new growth |
| May | Move outside when nights stay above 50°F; establish in full-sun position |
| June | Begin weekly feeding; water every 2–3 days; plant fills out quickly |
| July | Peak growth; water daily in heat; begin harvesting outer stalks once bases reach ½ inch |
| August | Continue harvesting; inspect for spider mites if plants show drought stress |
| September | Taper off feeding completely; monitor nights—plan indoor move as temps approach 50°F |
| October | Cut back to 6–12 in; repot if rootbound; move indoors before 45°F nights |
| November–December | Establish dormancy or houseplant routine; dormant plants: water once monthly only |
| January–February | Minimal care; watch for first new shoots in late February as days lengthen |
Frequently Asked Questions
Can I grow lemongrass in a pot indoors year-round without moving it outside?
Yes—with a grow light providing 12+ hours per day and consistent watering and feeding. Without supplemental light, most indoor windows produce thinner, less fragrant plants compared to a summer outdoors. A south-facing window in a warm room can work, but growth will be slower and stalks less robust.
How do I start lemongrass from grocery store stalks?
Place fresh, uncut stalks in a glass of water in a sunny spot. Roots appear within about two weeks [5][2]. Pot them up once roots reach an inch long and harden them off gradually before moving outside.
When should I divide a rootbound container plant?
Fall, just before moving indoors, is the ideal window [9]. The plant has finished growing for the year, division stress is low, and each division overwinters easily. Use a serrated knife to split the root ball into sections of two or three stalks each, and plant each section so the top of the root ball sits about an inch below the rim.
Sources
- “How to grow Lemongrass” — RHS
- “Lemongrass in the Garden” — Utah State University Extension
- “Lemongrass” — University of Florida IFAS Extension
- “Lemon Grass” — University of Illinois Extension
- “Lemongrass” — University of Wisconsin-Stevens Point
- “Lemongrass Winter Care” — Gardeners Path
- “Is Lemongrass a Perennial?” — Savvy Gardening
- “Growing & Planting Lemongrass” — Bonnie Plants
- “Repotting Lemongrass” — Gardening Know How
