A windowsill seems like the perfect place for houseplants – lots of natural light, a nice height, a view of the world… But if plants could talk, they would definitely tell you in the winter: “Please don’t put me there again!” During the colder months, window sills often become a dangerous place for many popular types of houseplants. The reason? The combination of cold air from outside and dry, warm air from radiators below creates extreme microclimate conditions that are not at all pleasant for plants.
Mostly room plants originates from tropical or subtropical areas, where temperatures are relatively stable throughout the year. These plants cannot withstand temperature shocks – not even short-term gusts of cold air, let alone long-term exposure to cold glass or drafts. The consequences are quickly visible: yellowed leaves, dry edges, brown spots, stunted growth, wilted appearance despite watering. If we want to help them survive the winter without stress, we must remove them from the windowsills as soon as possible.
Why is a windowsill not a safe haven for houseplants in winter?
1. Dangerous temperature fluctuations
The glass surface of a window acts as a refrigerator in winter. Even if the room is a pleasant 22 °C, the temperature right next to the glass can be much lower – sometimes even falling below 10 °C, especially at night. This is stressful for plants that are adapted to stable heat. If roots or leaves come into contact with the cold surface, cell damage can occur, which is externally manifested as brown spots or even tissue death.
2. Dry air from radiators
Most radiators are located directly under window sills, which means that plants are in close proximity to dry, warm air. This is a double whammy: the air is unsuitable for moisture-loving plants, and it also speeds up the evaporation of moisture from the leaves and soil. This causes the plant to become dehydrated, even if it is watered regularly.
3. Drafts and thermal shocks
Every time we ventilate our apartment (which is a must!), cold air enters the room through a window or door. Tropical plants are not used to such changes and often react by stunting their growth or massive leaf loss. A single night with an open window can cause irreparable damage to some species.
Remove these houseplants from your windowsills immediately!
Ficus (Ficus elastica, F. benjamina, etc.)
Ficus is a popular houseplant with luxurious, leathery leaves. However, it is extremely sensitive to temperature changes and drafts. Even a short exposure to cold air can cause massive leaf loss, which is often shocking to the owner. It is important to place the ficus away from windows, doors and radiators - in a room where conditions are stable.
Calathea (Calathea spp.)
Calatheas are true divas among plants – their patterned leaves make you want to frame them. But this beauty also comes with high demands: humid air, heat, no drafts. When the temperature drops, their leaves begin to curl, the edges become dry and brown. The cold air and the dryness of heated rooms are a combination that completely destroys the delicate internal ecosystem of the calathea.
Spathiphyllum (Peace Lily)
Spathiphyllum is famous for its elegant appearance and ease of care – as long as you don’t leave it in a draft. Cold air causes it shock: the leaves wilt, turn yellow, and the plant may even stop blooming. It is particularly sensitive to drafts at the ground, so don’t place it near doors or windows that you often open. However, in ideal conditions with high humidity and even heat, it will delight you with new leaves and white flowers even in winter.
So where do you go with your plants in winter?
If your windowsill acts like a glacial plateau in the winter, it's time to move. Find an alternative:
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- A bright corner away from drafts – even a meter or two away from the window will be enough if the plant has enough light.
- Room with humidity above 50 % – for moisture-loving plants, consider using a humidifier.
- Stable temperature – no heat waves from radiators or cold gusts of air.
- Insulation from cold surfaces – plants should not be in direct contact with cold window sills or ceramic tiles.
Houseplants aren't just decoration – they're thermally sensitive creatures
Although houseplants act as patient roommates, they quickly show when they don't like something. And winter is a real challenge for many indoor beauties. By placing plants incorrectly, we can inadvertently cause them stress, which leads to illness or even death. If we want them to continue to delight us in spring, we need to provide them with optimal conditions now.
