Cold Damage in Chinese Evergreen — The Problem That Appears Weeks Later
Chinese Evergreen (Aglaonema commutatum (and related cultivars))
Symptoms
- brown, water-soaked patches on leaves — often irregularly shaped and spreading
- patches appearing days or weeks after a cold exposure, not immediately
- leaves closest to a cold window, exterior wall, or air conditioning vent most affected
- the patches feel soft initially, then dry and papery as they age
- overall leaf yellowing in severely affected leaves
Causes
Exposure to temperatures below 60°F (15°C)
Aglaonema evolved in the consistently warm forests of Southeast Asia, where temperatures rarely drop below 65°F (18°C) year-round. When leaf tissue is exposed to cold — from a cold window pane, a cold draft through a door, an air conditioning vent in summer, or transport in cold outdoor air — the cellular membranes of the leaf cells are disrupted. This disruption does not immediately produce visible symptoms in many cases: the cells die over the following hours to days, and the resulting brown patches appear to emerge spontaneously long after the cold event. This is why cold damage is frequently misidentified as fungal disease or overwatering — the grower has already fixed the cold exposure by the time the patches appear and does not connect the current damage to the past event.
Cold soil from cold floors or cold water irrigation
Chinese Evergreen roots are also sensitive to cold. Pots placed on cold tile or concrete floors in winter, or watered with cold tap water, can experience root-level cold stress. This manifests more slowly than leaf-level cold damage but produces a general decline in plant health — reduced growth, yellowing leaves — rather than the distinct brown patch pattern of direct leaf cold exposure.
How to Fix It
- 1
Remove the plant from any cold exposure immediately: away from cold windows, drafts, vents, or cold floors. This stops ongoing damage, though damage already initiated in the cells will still manifest over the next several days.
- 2
Do not remove damaged leaves immediately. While the patches are unattractive, the remaining green portions of damaged leaves still photosynthesize. Wait until the leaf is fully brown and clearly dead before removing it.
- 3
Place the plant in a consistently warm location (68–80°F) with moderate humidity. Warmth supports recovery and limits further cellular stress.
- 4
Do not increase watering after cold damage — this is a common error. Cold-damaged cells cannot absorb water normally, and excess moisture in cold-damaged soil can lead to root issues. Maintain normal watering intervals.
Prevention
- Keep Chinese Evergreen above 60°F at all times — this is non-negotiable
- Position away from exterior walls and windows in winter — even glass that is not frosted is cold enough to cause damage when leaves press against it
- Never place near air conditioning vents in summer
- Water with room-temperature water, never cold water
- Elevate pots from cold floors using a trivet or felt pads in winter
Quick Summary
| Plant | Chinese Evergreen (Aglaonema commutatum (and related cultivars)) |
|---|---|
| Category | Environment |
| Likely causes | Exposure to temperatures below 60°F (15°C), Cold soil from cold floors or cold water irrigation |
| Fix steps | 4 steps — see above |