Diagnostic sheets · Leaf
Crispy brown tips: the four causes and how to tell which one you have
Brown leaf tips look identical whatever caused them, which is why so many people treat the wrong thing for years. In practice there are four causes and each has a tell: fluoride leaves a hard straight line, low humidity leaves soft curling edges, salt burn leaves a white crust, and underwatering leaves the whole leaf dull.
| Symptom | Crispy brown tipsLeaf |
|---|---|
| Likely causes listed | 5 |
| Confusable conditions | 3 |
| Remedies listed | 6 |
listLikely causes
- Fluoride in tap water: the classic cause in Dracaena, spider plant, Yucca and Cordyline, where brown always starts at the tip and moves down.
- Low humidity: crisp tips on the leaves most exposed to dry air, usually the ones furthest from the humidifier and nearest the radiator.
- Fertiliser salt build-up: brown tips plus a white crust on the mix surface and the pot rim, after months of feeding without flushing.
- Underwatering: dry air plus dry soil, with the whole leaf losing gloss and the tips going brown before the margins do.
- Overwatering in a plant with root damage: tips brown while the leaf also yellows, because the plant cannot move water at all.
listWhat to do
- Switch to rainwater or distilled water if the plant is a Dracaena, spider plant, Yucca or Cordyline. Standing tap water overnight removes chlorine but not fluoride.
- Raise humidity above 50% with a humidifier or by grouping plants. Misting helps temporarily but the effect lasts minutes.
- Flush the pot: pour three pot-volumes of room-temperature water through the mix and let it drain completely. Do this twice a year on any plant you feed.
- Trim the brown tip with scissors, following the curve of the leaf, leaving a 1 mm margin of brown rather than cutting into green tissue.
- Move the plant away from radiators, air conditioning vents and draughts, which lower the humidity around the leaf to well below the room average.
- Do not feed a plant that has salt burn until you have flushed the pot and seen new growth.
differentialConfusable conditions
| Normal leaf senescence | An old leaf going brown along the whole margin and then the tip, over weeks. That is ageing, not tip burn. |
|---|---|
| Sun scorch | Brown patches in the middle of the leaf where a water droplet focused sunlight, not only at the tip. |
| Fungal tip blight | Brown tip with a yellow halo and a soft, dark advancing edge. Tip burn has a hard, dry edge with no halo. |
presentationWhat you are seeing
- The tip of the leaf, and sometimes the last two centimetres of the margin, dies and turns brown while the rest of the leaf stays green.
- The boundary between brown and green is usually sharp, and the brown tissue is dry and brittle rather than soft.
aetiologyWhy it happens
- Fluoride and boron accumulate at the leaf tip because the transpiration stream ends there. Dracaena, spider plant, Yucca and Cordyline are exceptionally sensitive and will show tip burn on tap water at 0.7 mg/l fluoride within a year.
- Low humidity makes the leaf margin lose water faster than the roots replace it. The tip and margin have the highest surface-to-volume ratio and dry out first.
- Salt burn: fertiliser salts accumulate in the mix because every watering adds more and nothing removes them. The high salt concentration at the root zone reverses osmosis and pulls water out of the plant.
- Underwatering produces tip burn only in combination with dry air — the plant prioritises the leaf centre and lets the tip go.
managementWhat to do
- Check the mix surface and the pot rim for a white or cream crust. If there is one, it is salt burn and flushing is the fix.
- Check which leaves are affected. If it is the oldest and largest leaves, the cause is likely fluoride or salt. If it is the leaves nearest the radiator, it is humidity.
- Switch the water source for sensitive species and give it three months. The existing brown tips will not recover; the test is whether new leaves come through clean.
- Flush the pot twice a year if you feed regularly, and never let a plant stand in its drainage water.
- Trim brown tips cosmetically but leave a sliver of brown, because a cut into green tissue simply creates a new brown tip.
The white crust test
Look at the surface of the mix and the inside rim of the pot. A white, cream or pale yellow deposit — sometimes crystalline, sometimes a fine powder — is accumulated fertiliser salt. If you see it and the leaf tips are brown, you have your answer and you do not need to change your water.
Salt burn is caused by feeding without flushing. Soluble fertiliser leaves salts behind as the plant takes up water and the mix dries; those salts stay in the pot. After a year of monthly feeding, the concentration in a 15 cm pot can be high enough to damage roots.
The fix is a flush: three pot-volumes of room-temperature water poured slowly through the mix and allowed to drain away completely. Do it in a sink, not on the saucer. Repeat twice a year as routine maintenance on any plant you feed.
- White crust on mix or pot rim: salt burn — flush
- Hard brown tip, sharp line, no crust: fluoride — change water
- Tip burn only on leaves near a radiator: low humidity
- Whole leaf dull plus brown tip: underwatering
- Brown tip with a yellow halo: fungal, not tip burn
Which plants are fluoride-sensitive
Fluoride tip burn is not a universal houseplant problem. It affects a specific group that transports fluoride to the leaf tip rather than sequestering it in the roots: Dracaena of all species, spider plant (Chlorophytum), Yucca, Cordyline, and to a lesser degree Maranta and Calathea.
If your plant is in that group and you water it with fluoridated tap water, tip burn is close to inevitable. Most UK and US tap water is fluoridated at 0.7-1.0 mg/l, which is well above the 0.25 mg/l that begins to damage Dracaena.
Rainwater is free and best. Distilled water in two-litre bottles costs very little for a plant that needs a litre a week. An ion-exchange filter jug removes most fluoride and is the most convenient option.
Humidity, and why misting does not work
Misting raises the humidity around the leaf for a few minutes at most, then the water evaporates and the humidity returns to the room value. For a plant that needs 60% and is in a room at 30%, misting is not a treatment.
What works is either a humidifier within two metres, or a pebble tray directly under the pot that is kept topped up. A pebble tray gives 5-10% above room humidity in the immediate area, which is modest but real and continuous.
The most effective single change in most homes is moving the plant away from the radiator. The humidity two metres from a radiator can be half the humidity five metres away, and the leaf temperature is higher, which increases transpiration further.
Plants this applies to
| Spider plant: brown tips, and why this one really is the water | Chlorophytum comosum is the plant most often recommended for beginners and the one most often described as having brown tips from low humidity. For… |
|---|---|
| Calathea orbifolia: a plant that is honest about humidity | Goeppertia orbifolia — still sold as Calathea — has the largest leaves of the common prayer plants, and the least tolerance for dry air. It is not a… |
| Boston fern: the plant that needs water three times a week | Nephrolepis exaltata is not difficult, it is demanding. It wants water every two or three days in summer, humidity above 60%, and light that is bright… |
| Prayer plant: the nightly leaf movement is your best diagnostic tool | Maranta leuconeura folds its leaves upward every night and opens them flat every morning. That daily cycle is more useful than any soil meter, because… |
| Aloe vera: the plant that rots because it is treated like a houseplant | Aloe vera is a desert plant that people keep indoors and water like a fern. It needs more light than any window in a northern-facing room can give… |
Troubleshooting
I switched to distilled water two weeks ago and the tips are still brown. Is it not working?
Is it safe to cut the brown tips off?
My spider plant has brown tips but my pothos next to it does not. Why?
CaveatCultivation guidance only, not a plant pathology diagnosis: the same symptom usually has several unrelated causes, so treat the least invasive cause first and change one variable at a time. If a plant is valuable to you, isolate it before treating.
Published2026-09-02 ·