Lemongrass grows slowly for its first few weeks, then takes off once summer heat arrives.
From a nursery plant set out after your last frost, you can expect your first harvestable stalks in about 3 to 4 months, while store-bought stalks take about 4 to 5 months and seeds take 5 to 6 months or more. By late summer, a healthy plant in the ground can stand 3 to 5 feet tall.
That speed depends almost entirely on warmth. Lemongrass is a tropical grass, so a cool spring stalls it, and a hot, sunny July can add inches a week.
Once you know which starting method and conditions you’re working with, you can plan a realistic harvest date and avoid waiting on a plant that’s missing something simple.
The Short Answer: When Can You Expect a Harvest?
Most gardeners get their first usable stalks 90 to 150 days after planting. The exact date depends on how you start and how warm your summer runs. If you are stocking up, a balanced liquid fertilizer is the first thing I would pick up.
I judge readiness by the plant, and I don’t pay much attention to the calendar. I look for two harvest signs:
- The plant stands at least 12 inches tall.
- The stalk base is about ½ inch thick, with a firm, swollen white core.
Lemongrass grows slowly until summer heat arrives, then increases in size dramatically. Plants typically produce several harvestable stalks by the end of summer.
In most of the US, that means your biggest harvest lands in August and September, even if you planted in May.
If you live in zones 10 to 11, the plant keeps growing almost year-round. You can cut stalks for months once the clump fills out.
Lemongrass Growth Timeline by Starting Method
The lemongrass growth timeline runs fastest from a live plant and slowest from seed. The table below shows typical ranges for West Indian lemongrass (Cymbopogon citratus) grown outdoors in full sun after nights stay above 60°F.
| Stage | Nursery plant or division | Store-bought stalk | Seed |
|---|---|---|---|
| Rooting or germination | Already rooted | 1 to 3 weeks in water | 10 to 21 days |
| Ready to plant out | Right away | When new leaves appear, 3 to 4 weeks | 8 to 10 weeks after sowing |
| Slow establishment | 2 to 4 weeks | 4 to 6 weeks | 6 to 8 weeks |
| Fast summer growth | Weeks 4 to 12 | Weeks 6 to 16 | Weeks 10 to 20 |
| First harvest | 3 to 4 months | 4 to 5 months | 5 to 6+ months |
| Late-summer height (in ground) | 3 to 5 feet | 2 to 4 feet | 2 to 4 feet |
These ranges assume steady water and summer feeding. A cool, cloudy summer pushes every column back by several weeks.
Fresh grocery stalks usually root in a glass of water in about 2 weeks. Seeds germinate in about 10 to 21 days at 70 to 75°F.
How Does Your Starting Method Affect Growth?
Your starting method sets how much of the season the plant spends building roots before it can put on height. A potted plant arrives with roots and leaves ready to work.
A stalk has to grow roots first. A seed has to grow everything from scratch.
Nursery Plants and Established Divisions
Live lemongrass plants are my top pick if you want stalks this year. They’re already rooted, so they skip the riskiest stage and start growing as soon as the weather warms.
A division from an existing clump is just as quick. Dividing a clump is the fastest way to get a good crop; I use a fist-sized cluster of shoots with roots intact.
Expect a slow first few weeks while roots spread into new soil. After that, a nursery plant set out in late May can give you thick stalks by late August.
Rooted Stalks and Store-Bought Cuttings
Stalks from an Asian market are cheap and work well. Pick firm, green stalks with the base still intact. Then stand them in an inch or two of water and change it every couple of days.
Roots show up in 1 to 3 weeks. I’d wait to plant until you see fresh leaves growing from the center, because that tells you the roots can support the stalk. You can follow my steps to regrow lemongrass from store-bought stalks.
A rooted stalk starts as a single shoot, so it needs a few extra weeks to send up side shoots and form a clump. That clump is what gives you several stalks to cut.
Seeds and Seedlings
Seed is the slowest route. Start it indoors 8 to 10 weeks before your last frost. Press the tiny seeds lightly onto the soil surface and barely cover them. Keep the soil at 68 to 86°F.
Seedlings stay thin and grassy for weeks. Transplant them once they’re about 3 inches tall and the outdoor weather is warm. In northern states, a seed-grown plant often reaches harvest size only by September.
Seed packets also vary. Some sell East Indian lemongrass (C. flexuosus), which is a different plant from the C. citratus sold in stores. If you’d still like to try it, here’s how to grow lemongrass from seed.
What Helps Lemongrass Grow Faster?
Lemongrass grows fastest with three things: heat above 75°F, lots of direct sun, and a steady supply of water and nitrogen.
Warm Temperatures and Direct Sun
Lemongrass grows best with daytime highs around 75°F or warmer and nights near 60°F or above. Below about 55°F, growth nearly stops.
Give it at least 6 hours of direct sun. Eight or more is better. The plant handles full sun even in the hot Southeast and Southwest. You can learn more about how much sun lemongrass needs for your site.
For a faster start, I like these warm spots:
- Against a south-facing wall or fence
- Near paving that soaks up heat
- In a dark container on a sunny patio
Steady Moisture and Summer Feeding
Lemongrass comes from humid tropics, so dry soil slows it quickly. Water when the top inch of soil feels dry, and keep the soil evenly moist without letting it go soggy. A 2-inch mulch layer helps plants in the ground hold water.
Like other grasses, it uses a lot of nitrogen. I feed every 2 to 3 weeks from June through August with an organic liquid fertilizer that’s balanced or nitrogen-rich. Utah State recommends feeding potted plants more often, with a half-strength solution weekly.
Stop feeding by early September so the plant can slow down before cold weather. My lemongrass care guide covers the full feeding schedule.
What Slows Lemongrass Growth?
Cool temperatures cause the most stalled lemongrass. Shade, cramped roots and uneven watering follow close behind. Most slow plants have one or two of these problems, and each one is easy to spot.
Cold Weather and Too Much Shade
If you plant too early, lemongrass sits still for weeks. Nights in the 40s and 50s don’t kill it right away, but they keep the roots from spreading. I wait until nights stay above 60°F before planting, even if that pushes planting into early June.
Shade slows growth in a quieter way. With fewer than 6 hours of sun, you get thin, floppy leaves and skinny stalks that never thicken to ½ inch.
A spot that gets 4 hours of morning sun will keep the plant alive, but it won’t give you much to cook with.
Cold also changes the leaf color. If the blades show reddish tints after chilly nights, see my notes on lemongrass turning purple or red.
Small Pots, Crowded Roots, and Water Stress
Lemongrass roots fill a pot fast. Once they circle the container, top growth slows and the soil dries out within a day. Signs of a root-bound plant include:
- Roots poking out of the drainage holes
- Water running straight through the pot
- Brown leaf tips and thin new shoots
Missed waterings do similar damage. A pot that dries out completely in July can set growth back by a week or more. If yellowing or browning spreads, look at the common causes of why a lemongrass plant is dying.
How Does Growth Vary by US Region and Season?
Your region decides how long the fast-growing window lasts. In zones 10 and 11, lemongrass grows for most of the year. Northern gardeners get about 3 to 4 strong months.
Frost-Free Areas and Long Growing Seasons
In South Florida, South Texas, Southern California and Hawaii, lemongrass is a true perennial. A clump there can reach 6 feet tall and 4 feet wide.
Zone 9 gardeners along the Gulf Coast and in parts of Arizona and California can usually keep plants in the ground with mulch and frost cloth. The tops may die back in winter, and new growth returns in spring.
In these areas, plant in March or April and you’ll often cut stalks by early summer.
Shorter Seasons in the Northeast, Midwest, and Pacific Northwest
North of zone 9, lemongrass grows as a summer plant. Here in New York, I plant in late May or early June, and the plant does most of its growing in July and August.
The Pacific Northwest is harder. Cool summer nights slow growth even when the days are mild, so a pot on a hot, south-facing patio beats a bed in the open garden.
In northern regions lemongrass reaches about 3 feet tall, and more in a very hot summer.
| Region | Plant out | Fast growth | Typical first harvest |
|---|---|---|---|
| Southeast and Gulf Coast | March to April | May to October | June to July |
| Southwest | March to April | April to October | June |
| Midwest and Northeast | Late May to early June | July to August | August to September |
| Pacific Northwest | Early June | July to August | September |
Does Lemongrass Grow Faster Outdoors or Indoors?
Lemongrass grows much faster outdoors in summer than it does inside. Strong sun and heat drive its growth, and few homes supply enough of either.
Outdoor Growth During Warm Weather
Outdoors in July, a healthy clump can add several inches a week. It sends up new side shoots from the base, and each one becomes another stalk to harvest.
Outdoor air also brings humidity and rain, which this tropical grass likes. I suggest a two-week hardening-off period in a shady, sheltered spot before planting. That step keeps sunburn and wind shock from costing you growing time.
Indoor Growth and Light Limitations
Indoors, lemongrass mostly holds steady. Plants grown inside produce fewer stalks because of low light.
A bright south-facing window helps. A full-spectrum grow light set 6 to 12 inches above the leaves for 12 to 14 hours a day helps more.
Indoor air in winter is also dry, so watch for spider mites, which show up as fine speckling on the leaves.
I treat indoor time as a way to keep the plant alive between summers, and I don’t expect much new growth. If you’d like to keep a plant inside year-round, here’s how to grow lemongrass indoors.
How Big Does Lemongrass Get in the Ground or a Pot?
Lemongrass in the ground typically reaches 3 to 5 feet tall in one US season, and in frost-free areas it can reach 6 feet. Pots keep it smaller, often 2 to 3 feet, depending on container size.
Mature Height and Clump Spread in Garden Beds
A garden pl