What Kind of Light Does My Plant Need?

In general, there are four terms used for the kind of light needed for indoor plants: direct light, bright indirect light, medium light, and low light. 

Direct light is when sunlight directly hits your plant. This is usually a plant that is sitting close to a South or West facing window or kept in a sunroom. The most common plants that like direct light are succulents and cacti. 

Hoyas can tolerate some direct light and can turn a little red on their leaves. This is called sun stress and does not damage the plant. It is similar to getting a suntan. Putting plants that are not suited for direct light in these conditions, can lead to the burning of your plant’s leaves. This often manifests as brown or yellow splotches or crisping around leaf edges. The use of certain treatment sprays or humidifiers can also increase the likelihood of leaf burn on plants in direct sunlight.

Bright indirect light is best described as the area just outside of where a cat would sunbathe. This area should receive sunlight most of the day, such as from a Sothern-facing window, with the plant being kept a bit farther back into the room or it receives the light through sheer curtains. Most house plants needs fall into this light category since it mimics their natural habitat where the sunlight would be filtered and partially obstructed by the leaves and branches of trees and other plants. 

Medium light is where the light hits the plant some of the day, such as from an East window, West window, or a large North-facing window, in a room with light-colored walls. If your Southern windows are small, you have a lot of light obstruction, or the plant is tucked away into a distant corner of the room this would also be considered medium light. Plants with sensitive leaves such as Calatheas do well in these conditions.

Low light does not mean no light; all plants need some sort of light to photosynthesize. Most North-facing spaces, rooms with blinds pulled or very small windows, areas in your house that may not have a window directly in them, but the room receives light from another room that has windows, are considered low light areas. There are very few plants that actually like low light, though there are a few that will tolerate it such as Snake Plants or ZZ’s.

What does “can tolerate low light” mean?
A plant that tolerates low light means that if placed in a low light setting it will not suffer from leaf loss or serious debilitating effects. In low light areas, plants will grow much slower, will not flower, and may lose color or variegation. You will not want to water as deeply or frequently if your plant is in a lower-light environment. You know a plant is in too low of light for its needs if it becomes leggy or stretches towards more light.

What plant can I have in a room without any windows?
There are no plants that can tolerate zero light. If you have a room without windows, and you want to have plants in it, the best thing you can do is to use a grow light. There are a lot of different kinds out there, including full-spectrum bulbs that will fit into a regular lamp or light fixture.

How does the location of my windows affect my light?
The sun rises in the East and sets in the West. In the Northern hemisphere, the sun is always to the South. These are important things to know when deciding how much light a room has. East-facing windows filter in the cool, morning light, while West-facing windows have more intense, hot light. South-facing windows have the brightest light, and North-facing windows have the lowest. The size of your windows can also play a role in how bright the light is, as it determines how much light can come in. Having light-colored walls and floors allows the light to bounce off of these surfaces, producing a brighter space for your plants whereas dark flooring and dark walls make it dimmer.