Understanding a plant’s native habitat gives clues to its care, and houseplants are no exception. Many common houseplants are native to the tropics, where the climate most closely approximates our homes’ interiors — relatively stable temperatures, never freezing, with a range of light levels. In particular, many favorite houseplant species are adapted to the jungle understory beneath tall trees, where they bask in warmth, high humidity, and whatever sunlight filters through the tall trees’ foliage. Other plants hail from sunnier, less humid climates. The closer you can come to replicating a houseplant’s native habitat, the better your chance for success.
Relying on Window Light
Many of us assume that the sunlight coming through our windows will be adequate for our houseplant, and in some cases it is. However, light that passes through glass isn’t as strong as direct, outdoor sunlight. Also, unless you’re growing in a greenhouse, its brightness will change throughout the day depending on the dirction the window faces.
Other factors affecting the amount of sunlight coming through a window include the size of the window, eaves and overhangs, and shading by trees and buildings. In winter, the sun is lower in the sky so there may be more direct sun; however, the intensity is weaker than in summer, and there are fewer hours of daylight.
Here are some terms used to describe a houseplant’s light preferences and the window location that might best suit it:
Bright light with some direct sun
In the northern hemisphere, the most sunlight will come into a south-facing window. However, the brightness and duration will depend on the factors above. West-facing windows offer shade in the morning, but direct sun in the afternoon. In summer, this is usually the hottest part of the day, so plants will receive some extra heat, too.
Bright, indirect light
Sheer curtains will transform the intense sunlight of a south-facing or west-facing window into the bright, indirect light favored by many houseplants. Another good location is an east-facing window, which provides a few hours of morning sun, which tends to be less intense and produce less heat than afternoon sun.
As you move plants away from windows, the light intensity is lessened. Placing a medium-light plant about five feet in from a south- or west-facing window should provide adequate light.
Interior walls and north windows are often low-light areas. The more windows you have, the brighter your interior space will be. Note that plants described as “low light” generally tolerate low light, but would grow more vigorously with medium light. And no living plant will thrive in a very dark corner.