Brown tips, yellow blades, stalks that flop over like wet noodles: if that’s what you’re seeing, it’s easy to think your lemongrass plant is dying, but most clumps can still be saved.
Lemongrass is a tough tropical grass, and it shows stress loudly long before it’s gone.
Most lemongrass declines because of a watering problem (too wet or too dry), cold weather, or too little sun, and a clump with a firm, pale base can almost always recover once you fix the cause. Match your plant’s symptom to the sections below, then check the base before you give up on it.
Is Your Lemongrass Plant Dying or Just Dormant?
A lemongrass clump that turns tan in fall or winter is often just resting, especially if the stalk bases are still firm. Cold-season dieback looks dramatic, so it’s worth checking the crown before you pull anything out. If you are stocking up, a balanced liquid fertilizer is the first thing I would pick up.
What Does Normal Winter Dieback Look Like?
Lemongrass slows down once temperatures stay below about 50°F, and growth stalls when nights drop under 45°F. The outer blades fade to straw color, the tips dry out, and the whole clump looks tired.
Lemongrass is a tender perennial, and in most of the US it only stays evergreen in USDA zones 10 and 11. In the Northeast and Midwest, a hard frost kills the top growth outright.
In parts of the Southeast and Southwest, the clump browns on top and regrows from the base in spring.
Normal dormancy has a few clear traits:
- Browning starts on the oldest outer blades and moves inward.
- The change follows a cold snap or shorter fall days.
- No foul smell or slimy tissue shows up at the base.
- Potted plants indoors keep a few green blades in the center.
How Can You Check Whether the Base Is Still Alive?
I’d start with the firm-base test. Pull back the dead outer leaves and squeeze the lower inch or two of a few stalks right above the soil.
Living stalks feel firm and solid, like a green onion. Peel one thin layer and you should see pale cream, white, or light green tissue, plus that lemony smell.
A dead base feels hollow, papery, or mushy, and it’s brown all the way through. If most stalks pass the test, cut the top back to about 6 inches and wait for spring growth.
Why Are the Blades Turning Yellow?
Yellow blades on lemongrass point to soggy roots or a shortage of nitrogen, and the fix for each is opposite. That’s why the soil check comes before any feeding.
Check Wet Soil Before Adding Fertilizer
Push your finger 2 inches into the soil. If it feels wet and cold several days after watering, the roots are short on air, and fertilizer will only add stress.
Waterlogged lemongrass yellows across many blades at once, often with a limp look and a sour smell from the pot. Containers without drainage holes and heavy clay beds are the usual culprits.
Here’s what I’d do:
- Stop watering until the top 2 inches dry out.
- Empty any saucer sitting under the pot.
- Raise the pot on feet or bricks so water can escape.
- If the soil stays soggy for a week, move on to the root check further down.
Recognize Nitrogen Hunger in Older Leaves
Nitrogen shortage shows up as an even, pale yellow on the older outer blades first while new center growth stays greener. The soil feels normal, and the plant just looks washed out and slow.
Lemongrass is a heavy feeder during hot weather. Plants in the same potting mix for more than a season, or in sandy beds that drain fast, run low quickly.
A dose of balanced fertilizer every 3 to 4 weeks from late spring to late summer clears this up. New blades should come in darker green within two to three weeks; the yellow outer ones won’t turn green again.
Why Are the Blades Wilting or Folding?
Wilting or folded blades usually mean the plant is losing water faster than its roots can replace it. Hot afternoons, small pots, and dry soil are the common triggers, and watering lemongrass deeply is the main fix.
Check for Dry Soil and Heat Stress
Lemongrass comes from the warm, humid tropics, so it handles heat well only when its roots stay moist. When the soil dries out, the long blades fold lengthwise along the midrib to cut water loss.
Feel the soil. Dry, light soil that pulls away from the pot’s edge confirms thirst.
Heat stress is a separate clue. If blades fold at 3 p.m. on a 95°F day but stand back up by evening with moist soil, the plant is coping.
In the Southwest and the inland Southeast, afternoon shade for potted clumps helps during long stretches above 95°F.
Water Deeply Without Leaving the Roots Soggy
I’d water slowly until it runs out the drainage holes, then let the pot drain fully. For in-ground clumps, about 1 inch of water a week (rain included) keeps roots happy in summer, and more during heat waves.
Small pots dry out fastest. A mature clump in an 8-inch pot can need water daily in July, so I’d move it into at least a 5-gallon container.
Check the soil again before the next watering. If the top 1 to 2 inches are dry, water; if it’s still damp and the plant still wilts, suspect root rot instead.
What Causes Brown, Crispy Tips?
Brown, crispy tips come mostly from swings between bone-dry and wet soil, plus dry indoor air and normal aging of old leaves. A few crispy tips on a green clump are no cause for alarm.
Correct Uneven Watering
Lemongrass blades can grow 3 feet long, and the tips are the last spot water reaches. When the soil dries out completely between waterings, the tips die first and stay brown even after you water again.
A steady routine prevents new damage:
- Water when the top inch or two feels dry, every time.
- Spread 2 to 3 inches of mulch over in-ground roots to slow evaporation.
- Flush pots with plain water once a month to rinse out fertilizer salts, which also burn tips.
Account for Dry Indoor Air and Older Leaves
Indoor heating in winter drops humidity well below what lemongrass likes, so overwintered pots almost always get crispy tips. Grouping plants together or running a humidifier near them softens the damage.
Older outer blades also brown naturally as the clump grows, much like ornamental grasses do. If the center is green and new blades keep coming, that’s aging.
You can snip brown tips at an angle with clean scissors to tidy the look. My lemongrass care guide covers seasonal watering in more detail if your plant browns every winter.
What Do Rusty Orange Streaks Mean?
Rusty orange streaks or bumps on lemongrass blades point to lemongrass rust, a fungal disease. It weakens the plant over time, but you can manage it with cleanup and dry leaves.
Identify Lemongrass Rust
Lemongrass rust is caused by the fungus Puccinia nakanishikii. It starts as small yellow flecks or streaks on the leaves, then forms reddish-brown pustules, mostly on the undersides.
Rub a spot with a white tissue. If orange-brown powder comes off, those are spores, and they spread by wind and splashing water.
Rust shows up most in warm, humid weather, so gardeners in Florida, the Gulf Coast, and Hawaii see it often. Heavy infections cause blades to dry out and die early.
Remove Affected Leaves and Keep Foliage Dry
I’d cut off every streaked blade right away and bag it for the trash. Composting infected leaves keeps spores around.
Then change the conditions that help the fungus:
- Water the soil at the base, never the leaves.
- Water in the morning so any splashes dry fast.
- Thin crowded clumps to let air move through.
- Clean pruners with rubbing alcohol between plants.
For a clump that’s covered top to bottom, cutting all blades back to 6 inches lets clean new growth come in. Any fungicide you use should be labeled for edible herbs, and you’ll want to follow its harvest waiting period.
What Does a Soft, Mushy Base Mean?
A soft, mushy base means rot has reached the crown or roots, and it’s the most serious symptom on this list. Acting fast gives you the best chance of saving part of the clump.
Inspect the Roots for Rot
Slide the plant out of its pot, or dig around an in-ground clump with a garden fork. Rinse the roots with a hose so you can see them.
Healthy roots are firm and cream to light tan. Rotted roots are brown or black, slimy, and slip apart when you pinch them, often with a sour, swampy smell.
Check the stalk bases, too. If only a few stalks are soft, you can cut them away with a clean knife and keep the firm ones.
Improve Drainage Before Watering Again
Rot comes back if the soil stays wet, so I’d fix drainage before the next watering. Repot into fresh mix with about 1 part perlite or coarse sand to 3 parts potting soil.
Fabric grow bags are a good choice for rot-prone lemongrass because water and air pass through the sides. A 5- to 7-gallon bag suits a single clump.
In heavy clay, plant in a raised bed or mound the soil 6 to 8 inches high. After repotting, water once lightly and wait until the top 2 inches dry before watering again.
Why Are the Blades Purple or Red?
Purple or red blades on lemongrass most often come from cool nights, and the color fades once warm weather returns. Phosphorus shortage is a less common cause.
Consider Cold Stress First
When nights dip into the 40s°F, lemongrass makes extra red and purple pigment in its leaves. You’ll see it first on the outer blades, often in early fall or after a spring cold snap.
If the color appeared right after a chilly week, warmth is the fix. Move pots near a sunny wall or bring them inside once nights fall below 45°F.
Some lemongrass also shows reddish stalk bases naturally. I go into more detail on why lemongrass turns red, including heat and sun stress, in a separate post.
Check Growing Conditions Before Suspecting a Phosphorus Shortage
Phosphorus shortage causes purple tints on older leaves during warm weather, when cold can’t explain it. Cold, soggy soil also blocks phosphorus uptake, so check drainage and temperature first.
A home soil test tells you whether phosphorus is low and whether the pH sits in the 6.0 to 7.5 range lemongrass prefers. Only add a phosphorus fertilizer if the test shows a shortage.
For the full list of causes, see my post on why lemongrass turns purple.
Why Are the Stalks Thin and Weak?
Thin, weak stalks almost always mean the plant isn’t getting enough direct sun or the clump has grown too crowded. Both are easy to fix in one season.
Give the Plant Enough Direct Sun
Lemongrass needs at least 6 hours of direct sun a day, and 8 or more gives the thickest stalks. In partial shade, it grows leggy, pale, and floppy, with weak flavor.
Indoor plants by a north window almost always thin out over winter. A south-facing window or a basic LED grow light running 12 to 14 hours a day keeps them sturdier.
You can read more about how much sun lemongrass needs if your site is borderline.
Move outdoor pots to the brightest spot you have. In the Pacific Northwest and Northeast, a south-facing patio gives the extra heat lemongrass craves.
Divide Crowded Clumps
A clump packed into the same pot for two or more years runs out of root space and food. Stalks get skinnier each season, and the center may die out.
Dividing every one to two years in spring keeps stalks thick. The rescue steps further down walk through how to split a clump.
Which Pests Are Weakening the Leaves?
Spider mites are the most common pest on lemongrass, especially indoors in winter. Aphids and mealybugs show up less often, but they also drain sap and leave blades yellow and weak.
Look for Spider Mites on Indoor Plants
Spider mites love the warm, dry air of heated homes. Look for fine pale speckles on the blades, a dusty or bronze look, and thin webbing where leaves meet the stalks.
Hold a sheet of white paper under a blade and tap it. Tiny moving specks that leave reddish streaks when smeared are mites.
Outdoor plants get mites during hot, dry spells in summer, too. Damaged blades often turn yellow, then tan and crispy.
Check New Growth and Leaf Bases for Other Pests
Aphids cluster on tender new blades and leave a sticky film called honeydew. Ants climbing the plant are a good sign aphids are around.
Mealybugs look like small white cotton tufts tucked into the tight spots where blades wrap around the stalk. Peel back the outer leaf layers to find them.
Treat an Infestation Without Further Stressing the Plant
Start gentle, since you’ll likely be eating this plant:
- Rinse the blades with a strong spray of water, including the base, every few days for two weeks.
- Wipe mealybugs off with a cotton swab dipped in rubbing alcohol.
- For heavier problems, spray insecticidal soap or neem oil labeled for edibles, coating both leaf sides.
- Spray in the evening or out of direct sun to avoid scorching.
Trimming off heavily infested blades lowers pest numbers fast. Raising indoor humidity also makes life harder for mites.
How Can You Rescue a Struggling Clump?
A struggling clump recovers best when you cut away dead growth, divide out healthy stalks into fresh, free-draining soil, and feed