Environment Cold draught
Cold-blackened leaves
Leaves blacken or drop on the side facing a window or a door.
Also called: colddraughtfrostblack leaves
Severity
Keep an eye on it
Deal with it this week, before it spreads.
Parts affected
- Leaves
- Stems
- Flowers
- Fruit
- Roots
- Soil
Family
Environment
Cold, heat, dry air, shock after repotting: what comes from around it.
Understand
What is happening inside the plant
A cold draught does not cool the room: it strikes locally, in bursts, and the exposed cells freeze or dehydrate before the plant can adjust.
The affected tissue blackens, goes soft, then dries. The symptom is always directional, one side only, the side of the window, the door or the air vent. Tropical plants, used to steady temperatures, are the most sensitive, and a repeated draught eventually strips all the exposed foliage.
Check
How to be sure
Tick what you can see on your plant.
Tick the signs you can see and the gauge will add them up.
Some signs match. If the rest does not fit, look at the related problems further down.
Most of the signs match: this is very likely it. What to do
Signs and causes
What you see, and why
Symptoms
- Black or brown patches appearing overnight
- Leaves dropping abruptly
- The exposed side worse than the other
Causes
- Proximity to a poorly insulated window in winter
- Repeated opening of a door to the outside
- Air conditioning blowing straight onto the foliage
What to do
The action plan
In order. Tick each step once it is done.
0/3 done
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Move the plant away from the cold source today.
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Remove blackened leaves; they will not recover.
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Water less while the plant recovers.
Prevent
Stopping it coming back
-
Keep plants away from glass in winter.
-
Record any nearby air conditioning in the plant record.
Questions
Common questions
Is the cold of the glass enough?
On a winter night, yes: a leaf pressed against single glazing can sit several degrees below room temperature. Move the plant ten centimetres back.
Will the blackened leaves recover?
No, the tissue is dead. Cut them off once they are dry; the plant regrows from healthy buds.
Should I stop airing the room?
Definitely not, still air encourages disease. Move the plant while you air, or air the next room.
Keep an eye on it Limp leaves in high heat
The plant flops in the hottest hours and picks up again in the evening.
Causes and fixes
Keep an eye on it Sudden damage after the weather
Sudden damage after extreme weather such as frost, heatwave or wind.
Causes and fixes
Minor Brown, dry tips
Leaf tips and edges brown and dry.
Causes and fixes