Yes, Your Low-Light Plants Need (Some) Light to Thrive

Yes, Your Low-Light Plants Need (Some) Light to Thrive

Even if you live in a cave, there’s a way to give your plants the light they need to live.
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Plants need light to live. Without sufficient light, plants may become weak and struggle to grow properly. However, if your space doesn’t get a lot of natural light, don’t despair! The key to growing plants in low-light environments is understanding how much a plant really needs and how to supplement it.

What is low light?

The first thing to understand when reading a plant tag is that "low light" doesn’t mean "no light at all." All plants require at least a few hours of light. "Interior designers have long misused the term ‘low light’ as being the windowless corner of your living room," explains Darryl Cheng, author of The New Plant Parent and creator of House Plant Journal. He continues, "To a houseplant, that corner is nothing like under the forest canopy—it’s more like a cave."

"From a more technical standpoint, low light is usually considered to be about 100 to 200 or so foot candles," explains Justin Hancock, a horticulturist at Costa Farms. (Foot candles refer to the measurement of light intensity.)

Measuring light

The only way to truly understand light intensity is to measure it. "We need to use numbers instead of vague descriptions," says Cheng. The easiest way to measure light is with a plant light meter. The meters have a sensor that you place near a plant’s surface, which reads the intensity of the light that strikes the plant. The readout is typically in foot candles or lux. Ideally, you should take light meter readings for an entire day, so you have an idea of the light your plant is exposed to throughout the day.

What if you want to avoid investing in a light meter? No worries, but you will have to observe and take notes. Light is categorized as:

  • Direct light is full sun with no obstruction (1,000+ foot candles).
  • Bright, indirect light is well-lit, but no direct sunlight—about one to two feet from a window or light source (500 to 1000 foot candles).
  • Medium light is either some direct sunlight in the morning or indirect sunlight in the afternoon (100 to 500 foot candles).
  • Low light is a dimly lit room or an area that is in shade all day (100 to 200 foot candles).  

Observe your space for a full day to determine how much light it gets, and take notes. Keep in mind that there are seasonal differences in light intensity. "In winter, light levels are typically lower because the days are shorter and the winter sun is less intense," Hancock explains. "So a spot that’s pretty bright in summer could be low-light in winter. Or the converse can be true."

Choosing the right plants for low-light conditions

If your space doesn’t get enough light for medium-to high-light-loving plants like succulents, monsteras, or fiddle leaf figs, all is not lost. Some plants tolerate lower light but will need help to thrive. Plants that are typically classified as low light are:

  • Pothos
  • Philodendrons
  • Snake plants
  • Chinese evergreen
  • ZZs

"I must emphasize that these plants will tolerate low-light conditions; that is, they will hardly grow but still look okay for maybe a year," warns Cheng. "If you want them to grow nicely, you should prioritize giving the plants the best possible light."

Supplement the light

Thankfully, there is a way to increase the light in your home without hiring a contractor to install a new window or skylight. "A simple (but strong) LED lamp may be enough to transform a low-light spot into one that the plant can grow in," says Hancock, who further suggests using a mirror to bounce light onto the plant or rotating the plant between high and low-light areas.

If you want to go all in on supplemental lighting, consider getting a dedicated grow light. But you don’t need to get a large or multi-color commercial grow light. "Current white LED technology is relatively cheap and compliments your interior décor," says Cheng. "Any white LED light will do, but you should use a light meter to set the distance of the light to the plant correctly."

Proper watering

Plants that grow in lower light will grow more slowly. "They don’t usually need as much water," says Hancock. "So it’s even more important to feel or probe the potting mix with a moisture meter before watering to ensure you’re not keeping your plant too wet."

Cheng advises breaking away from old watering rules, like once a week or less in the winter, and observing your plants. "My approach to watering is by observing soil dryness alone—even if overall daylight hours are shorter, but your plant actually sees more direct sun during the winter, you will notice the soil dries out faster—and you’ll water accordingly," he advises.

Signs your plant needs more light

Even by supplementing the light and rotating your plant friend, there may still be some trial and error until you strike the right balance. Some things to look out for include:

  • Leggy (spindly, with long stems and leaves spaced far apart)
  • Sparse new growth or none at all
  •  Yellowing or dropping leaves

Thankfully, the best way to solve these issues is to add more light. If you give it your best shot and your plant is still struggling, consider propagating it and giving it another go.

Top image by Grant Harder, originally featured in "This Home is Complete with an Indoor Jungle"

Related Reading:

It’s Time to Make Your Own Potting Mix

How to Keep Your Plants (and Pets) Alive and Well

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