Lemon brown leaf tips and edges: causes and what to do
6 results in the diagnosis tree begin with brown tips and edges, 3 of them marked likely when the answers fit. They are ordered here for Lemon (Citrus x limon), using what its sources say about humidity, soil moisture, cold tolerance, watering and feeding and one problem recorded for it.
Sources last read 14 September 2026.
The lemon is a species of small evergreen tree in the Citrus genus of the flowering plant family Rutaceae. A true lemon is a hybrid of the citron and the bitter orange. Wikipedia, CC BY-SA 4.0
Native range: as a cultigen derived from artificial hybrids. (subtropical). Also sold as bergamot, bergamot orange, Chinese dwarf lemon, dwarf lemon, lemandarin and mandarin lime.
What Lemon’s sources say that bears on this
- Humidity
- ASHRAE recommends indoor relative humidity between 30% and 60%Penn State Extension · read 13 September 2026
- Soil moisture
- Moist but well-drainedRHS · read 13 September 2026
- Cold tolerance
- H2 — 1–5°CRHS · read 13 September 2026
- Watering
- In the growing season they need lots of water plus small, regular doses of nitrogen fertilizer to boost growth and fruit size.NC State Extension · read 13 September 2026While growing in spring and summer, water generously and mist every day. Use a citrus fertiliser all year round as directed by the manufacturer; give little water in winter.RHS · read 13 September 2026
- Feeding
- In the growing season they need lots of water and frequent light doses of nitrogen fertilizer to boost growth and fruit size.NC State Extension · read 13 September 2026Use a citrus fertiliser all year round, following the manufacturer’s directions; water sparingly in winter.RHS · read 13 September 2026
How this shows up on a Lemon
Edges of the leaves brown while the middle stays sound
Leaves on the side of the lemon nearest a heater or vent brown at the edges while those on the far side stay clean.
Penn State Extension cites ASHRAE's recommended indoor range of 30% to 60% relative humidity; a heated room in winter drops below it. Air that dry pulls water from the leaf faster than the roots replace it, and the margins are furthest from the supply.
Telling it apart: Where the plant stands. Browning concentrated on the side facing a heater points at the air.
Penn State Extension · read 13 September 2026Possible causes, likeliest first for a Lemon
Most likely too little water
Ranked higher because Lemon's recorded problems point this way.
- Moist but well-drained RHS · read 13 September 2026
Why: Soil dry two inches down leaves the roots nothing to send up, and the leaf edges are the last tissue in line.
What to try:
- Water thoroughly, until it runs from the drainage hole.Useful: pot with drainage holes
- Check the soil with a finger every few days rather than watering on a fixed day.Useful: moisture meter
What would settle it: Water it thoroughly and watch the next new leaves. If they come in with clean edges under steadier watering, the edges were thirst.
Most likely cold
Ranked higher because Lemon's recorded problems point this way.
- H2 — 1–5°C RHS · read 13 September 2026
Why: Soft, dark patches rather than crisp ones are damaged tissue rather than dried tissue.
What to try:
- Move it away from the glass at night, or keep the curtain on the room side of the lemon.
- Leave damaged leaves until new growth appears, then remove the worst of them.
What would settle it: Where the lemon sits at night, and what the glass feels like at that hour. Damage that appeared after one cold night, on the side facing the window, is the pattern.
Most likely a build-up of salts in the soil
- Loam; pH Acid or Neutral RHS · read 13 September 2026
Why: Minerals from tap water and fertiliser are left behind as water evaporates, and a white crust on the compost or the pot rim is where they show.
What to try:
- Water slowly and heavily until several times the pot's volume has run through the drainage hole, to wash the salts out.Useful: pot with drainage holes
- Scrape off the top layer of crusted compost and replace it.
What would settle it: Scrape the crust. If it is gritty and dissolves in water it is mineral; if it is fluffy it is mould, which is a different problem.
Less likely for a Lemon, still possible
Questions
- What usually causes brown tips and edges on a Lemon?
- For Lemon: most likely too little water, most likely cold and most likely a build-up of salts in the soil.
- How can I tell which one it is on my Lemon?
- Is the browning crisp and dry, or soft and dark? Crisp and dry; Soft and dark.
- What do Lemon's sources say about its soil moisture?
- RHS: Moist but well-drained.
- What does this look like on a Lemon?
- Leaves on the side of the lemon nearest a heater or vent brown at the edges while those on the far side stay clean. Telling it apart: Where the plant stands. Browning concentrated on the side facing a heater points at the air.
- Is Lemon safe to handle while I check it?
- Its sources list it as toxic to people. Wash your hands after handling the roots or sap, and keep trimmings away from pets.
Other plants that show brown tips and edges
CalamondinEdges of the leaves brown while the middle stays sound
AvocadoDry, curled edges on leaves near a heater
Bay laurelBrown tips on the newest leaves first
Chinese banyanLeaf tips go crisp and brown
Coffee plantLeaf tips go crisp and brown
Common figTorn or browned leaves on one side after windy weather
Something else wrong with the Lemon?
What this does not cover
This page orders a decision tree's results using a plant's sourced care. It has not seen your plant, its pot or its window, and two problems at once are common: that is the usual reason a confident answer turns out wrong. The questions in the diagnosis tool narrow it further than a list can.