With white walls, plants profit from abundant light. Photo: Le Sirenuse
Do you feel your houseplants aren’t getting enough light? Are they stunted, grow little and bloom less? Or do they produce long, pale, weak stems that bend towards the window (etiolation)? That means they’re starving for light.
If so, have you ever thought about painting the walls of the room white or at least a very pale color?
It may seem trivial, but the color of the walls, ceiling, floor and objects in the room makes a huge difference in the vigor of the plants that grow there.
Remember your physics class back in school. If black seems dark, it’s because it absorbs all the light rays that hit it. It is actually the absence of color. White, on the contrary, seems pale because it reflects all the rays. It is composed of all the colors. (By the way, plants appear green because they absorb all the rays that reach them except green.)
Plants need light for their survival: it’s their only source of energy. If dark walls or dark furniture absorb most of the light entering a room, the plants that grow there will capture less of it. On the contrary, in a room where white (or very light colors) dominates, a good part of the light is reflected back and forth until it is absorbed by the darker objects nearby by … such as plant foliage.
White Walls Turn Your Thumb Green
This is not a minor detail: the color of the walls makes a huge difference in how plants grow. In a room with pale walls (mirrors have the same effect), you can place plants well back from windows and they’ll do fine. In a room with dark walls, you’ll need to stick same plants right up against the window to get reasonable results.
I’ve been sharing this information for over 40 years and you have no idea the number of people who come to me to confirm that their thumb went from black to green (or vice versa) just because they painted their walls.
Even if houseplants are not your thing, if you’re a gardener, in just a few weeks you’ll probably start sowing vegetables and flowers for your garden. In that case, don’t forget that they too will greatly benefit from white or pale surroundings. Sometimes just a white panel placed behind the seedlings, so that sunlight bounces back towards them rather than diffusing into the room, completely changes their appearance … and your success rate!
Adapted from an article originally published on February 10, 2016.
Out in the landscape, white and light colors can actually contribute to sun scald of sensitive plants. It does not happen often, but I have inspected plants that got roasted during warm weather, just because they were next to windows that are designed to reflect sunlight.