Plant Care Basics: Light
Light and water are the most important aspects of plant care. Light drives a plant’s consumption of water, so if light conditions are poor or incorrect for your particular type of houseplant, the health of the plant will suffer. Remember, light is food for plants. Without it, they will starve!
Every home is different, so understanding the light in your home depends on the factors below but also on experience. Keeping an eye on your plants for signs of root rot (potentially not enough light) or leaf burn (too intense of light) will help you understand the light in your home.
The following are factors that influence the type of light your home receives:
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Listed in order of intensity:
Southern Facing Window - strongest light
Western/Eastern Facing Window - almost equivalent light
Afternoon sun (western window) tends to be a bit more intense than morning sun (eastern window)
Northern Facing Window - weakest light
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A window may have outdoor obstacles that block light from entering your home. Examples of this include trees, neighboring homes/ apartments, overhangs, etc. You want your plant to have a clear view of the sky to optimize the amount of light it receives.
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Winter has shorter days than summer, meaning that your plant is receiving less volume of light. It may not necessarily be receiving less intense light though (so watch out for leaf burn!). Often the winter sun is more intense than the summer sun and can even reflect off snow to further increase intensity. In addition, obstacles outside your window that provide some shade in summer may be removed in the winter. For example, a tree that normally blocks light in the summer would lose its leaves in the winter creating a clear view of the sky.
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When in doubt, put plants as close to a window as possible (just be careful of the type of plant, some plants cannot handle much direct sunlight.) Plants farther than 10 feet from a window are likely to be slowly dying. Remember, light is food for plants!
After considering the factors that influence the type of light your home receives, it is important to define some terms about light intensity often seen in houseplant care guides.
The plant community defines light in the following ways:
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The plant has a direct line of sight to the sun. (Not all tropical houseplants can tolerate direct sun, but many can tolerate a few hours a day). Cacti and succulents need direct sun to survive.
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The plant does not have a direct view of the sun but does have a direct view of the sky (on a clear day). Or the direct sunlight is being diffused by a curtain, blinds, trees, etc.
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Most tropical houseplants require this kind of light. The plant is receiving 6+ hours of light, but only a few hours of direct sun a day. Plants are generally close to the window and have no obstructions which inhibit light volume or intensity.
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Few plants will thrive in medium to low light conditions. These terms appear on care tags (especially at big box stores), but this really just indicates that these plants may tolerate, not thrive, in medium to low light conditions. These conditions are defined as areas in your home that are farther away from a window or that have obstructions that inhibit the volume or intensity of light (overhangs, neighboring homes, trees, etc). A north-facing window could also be considered medium to low light since it receives no direct sun throughout the day. Winter conditions or constant cloudy weather can also cause medium to low light conditions.
In general, only some plants— like cacti and succulents— need as much direct sun as possible. Most tropical foliage plants prefer to be as close to a window as possible receiving as much bright indirect light as possible. Looking up a plant’s specific light requirements is helpful, but following this general guideline is a good start. When considering light conditions for tropical houseplants, it’s best to maximize volume rather than intensity. This means that most tropical houseplants would prefer longer stretches of indirect light as compared to more intense direct sun.