Why are my plant’s leaves turning brown?
A leaf browning entirely — as opposed to spotting or tipping — usually means that leaf has already lost its water supply. The useful question is whether the cause is still active on the rest of the plant.
The causes, and how to tell them apart
Root rot from overwatering most common
How to tell: Browning progresses from the lowest leaves upward, often yellowing first, while the soil stays damp. Stems may be soft at the base.
What to do: Let the soil dry well down and inspect the roots. Trim away anything soft or brown and repot into fresh, faster-draining mix.
Severe drought common
How to tell: Leaves go crisp and papery rather than soft, the pot is very light, and the soil has pulled away from the sides.
What to do: Bottom-water for 20–30 minutes so the rootball rehydrates evenly, then return to a consistent schedule.
Sun scorch seasonal
How to tell: Browning confined to the leaves facing the window, often bleached or tan, appearing within days of a move into brighter light.
What to do: Move it back from the glass or filter the light. Scorched tissue does not recover — judge the fix on new growth.
Natural aging harmless
How to tell: A single oldest, lowest leaf, while new growth continues above.
What to do: Remove it once fully brown. Nothing else to do.
By species
The likely answer differs by plant — these species have their own version of this problem:
Plantroster compares this month's photo against last month's, so slow changes — the ones you stop noticing because you see the plant every day — get flagged.
Open PlantrosterOther problems
General horticultural guidance, not a diagnosis of your specific plant.