Lemongrass: brown, crisp leaf tips

What it is likely to be on lemongrass

1. Cold damage

   Candidate 1very common on this plant

   ·source

   Sourced guidancemoderate confidence

   • Royal Horticultural Society: Lemongrass — cultivation
   • Plant Finder — Missouri Botanical Garden: Cymbopogon citratus

   Checked 2026-08-13

   Blackened, translucent or limp tissue appearing suddenly after a cold night or a spell beside a draught. Tender plants show it well above freezing — basil blackens around 10 °C — so 'there has been no frost' does not rule it out.

   Points towards it

   • · growth stops below about 10°C and the foliage is damaged below about 5°C, which a British porch, greenhouse or unheated conservatory crosses every autumn
   • · the outer, oldest blades of the fan take it first while the centre of the clump stays green
   • · chilling takes the whole clump, or the side that was against the glass, rather than scattered leaves

   Argues against it

   • · damage appearing in hot weather is not cold injury — this rules it out entirely.
   • · bone-dry compost offers a simpler explanation for browning tips that does not require the plant to have been chilled

   Check this next

   Check the night temperature where the plant stands, and look at where the green stops. Cold damage runs down from the tips of the OUTER blades, often with a water-soaked grey band at the edge of the brown, while the heart of the clump keeps growing — and it appears within days of a cold night rather than gradually. A minimum-maximum thermometer left beside the pot for a week settles it more reliably than the leaf does.

   What to do now

   Bring it in before night temperatures reach 10°C rather than waiting for frost, and keep it above 12°C over winter, away from a cold pane and off an unheated floor. Cut the browned blades back to living tissue for appearance only — they will not recover — and water much less through the winter, because a cold lemongrass that is still being watered on a summer schedule rots at the base.

   ·source

   Sourced guidancemoderate confidence

   • Royal Horticultural Society: Lemongrass — cultivation

   Checked 2026-08-13

2. Underwatering

   Candidate 2common on this plant

   ·source

   Sourced guidancemoderate confidence

   • Royal Horticultural Society: Lemongrass — cultivation

   Checked 2026-08-13

   Easier to correct than overwatering and easily confused with it, because a plant short of water and a plant drowning both wilt. The distinguishing observation is not the plant at all — it is the compost, and it takes two seconds to check.

   Points towards it

   • · lemongrass evolved in seasonally flooded ground and has a high water demand in growth, so it browns quickly once the pot dries
   • · it happens in warm weather on a plant nobody has done anything to, simply because the pot is emptying faster than it is being filled
   • · the whole clump browns evenly at the tips, since it shares one root mass

   Argues against it

   • · the compost is wet, so the plant is not short of water and the browning has another cause — this rules it out entirely.
   • · a cold night immediately before the damage appeared points at chilling rather than at thirst

   Check this next

   Lift the pot and push a finger deep into the compost, then look at the calendar. Thirst browns the tips of every blade evenly during warm weather in a pot that feels light and is dry below the surface; cold damage arrives within days of a cold night, in compost that is usually still moist because the plant has stopped drinking. The two are told apart by weight and by date, not by the look of the brown.

   What to do now

   Water heavily and often through the growing season — lemongrass will stand in a saucer of water in summer, which almost nothing else on the same windowsill tolerates — and pot on into a container large enough to hold a day's supply. Cut browned tips off for tidiness only, and reverse the regime completely in winter: a dormant, cool plant needs the compost barely damp.

   ·source

   Sourced guidancemoderate confidence

   • Royal Horticultural Society: Lemongrass — cultivation

   Checked 2026-08-13

Narrow it down

This page lists everything at once, which is the right shape for reading and the wrong shape for deciding. The interactive tool asks one question at a time, starting with whichever would separate these causes fastest, and stops as soon as further answers would not help.

Opens with the plant and the symptom already set. Nothing you answer is stored or sent anywhere — the answers live in the address bar and nowhere else.

What this does not cover

These are the causes GrowingHQ holds rules for on lemongrass — not every cause there is. Where several problems look alike, the honest answer is often that they cannot be told apart by eye, and a page that named one would be guessing. If none of the above fits, the general brown, crisp leaf tips page lists causes across all plants, and the Lemongrass profile lists the problems it is prone to.