South-Facing Windows in Winter: Which Houseplants Suffer First

Many people think a south-facing windowsill is the best spot for houseplants. In an article for “Botanichka,” the author Anastasia Vysotskaya explains that the problem is not the window itself but a combination of factors: the radiator under the sill, cold glass close to the leaves, and low autumn sun. I liked her simple check: with the heating on, hold your palm near the leaves, and touch the glass early in the morning.

Four plants are at risk. Spathiphyllum develops pale and then brown spots near the glass, and drooping leaves don’t always mean thirst, so check the soil with a finger first. Calathea (Goeppertia) reacts with dry edges and faded patterns; it needs soft, settled water and a spot a meter to a meter and a half from the sill. Nephrolepis loses its small frond segments, especially in a hanging pot above a radiator. Weeping fig drops its leaves from cold, drafts and hot air.

The general advice is to move plants away from the heat while keeping their light. Usually 30 to 50 centimeters is enough, sometimes a meter. Don’t put pots directly on the radiator; place a cork or wooden board underneath. According to the author, spraying barely helps, but a humidifier works noticeably better.

The article also includes an honest caveat: if there is no radiator, the leaves are healthy, and there is enough light, the plant doesn’t need to be moved. Dry edges and burns won’t recover, so they can be trimmed carefully, and clean new leaves will show that the spot is right. For anyone growing finicky species like calatheas, this is a good reminder before the heating season.

Source: Botanichka