Plant Care 101

What Type of Lighting Do I Have, Anyway?

Decoding what we really mean when we say things like "bright, indirect" light

While we may all intuitively understand that plants require sunlight to grow, the nuances of indoor lighting can be one of the hardest things to get right for any plant parent. If you’re new to the world of houseplants, the so-called instructions for what light each plant needs can be completely overwhelming and not at all intuitive. And even if you’ve been a plant parent for a while, it can be easy to get mixed up. Providing the right lighting keeps our plant babies happy, healthy, and thriving.

For most houseplants, you'll find recommendations for things like “bright indirect light” or “direct light”. But what does that even mean? Well, lighting for your houseplants doesn't have to be a mystery. With the help of this guide, you’ll be armed with the knowledge (and options) to give all your plants that ~good~ light.

Types of Indoor Light

For you brand new plant parents out there: you’ve just acquired a plant to call your own. Depending on where you purchased or received them, your plant may have a set of “instructions”. Or maybe not. Either way, the one-liner on the care recommendations is often not enough to understand what that plant needs.

It can help to think back to science class when you learned about photosynthesis, which explains how plants turn sunlight into the energy they need to grow. It’s basically how they eat. And, just like animals and people, each type of plant has a specific way they've adapted to “eat.”

For houseplants, the typical natural lighting instructions come down to four main categories. We’ll go over each of these in-depth to help you find each source in your specific space or situation.

  • Direct Light (or Full Sun)
  • Bright, Indirect Light
  • Medium Light
  • Low Light (or Partial Shade)

P.S. For those of you who are seasoned plant parents, we’ve placed “Quick Facts” at the top of each definition. Even an expert requires a refresher now and then!

Direct Light (or Full Sun)

Quick Facts:

  • For a sun-loving plant, like a desert cactus or succulent
  • Found by unblocked south-facing windows
  • Direct light can burn plants that do not tolerate it

Direct light is the most intense and longest-lasting in your home. To find direct light for your houseplants, look for your largest, most south-facing window. It will be the rooms that get the most light throughout the day, and you typically never need to turn on lights during the day if your shades are open.

If you have larger plants, such as a mature cactus or citrus tree, place them in the part of the house that will get the most light from those south-facing windows. Right in front of the window is best! For smaller plants, such as succulents and herbs, you can place them right on a windowsill that floods with sunlight often.

Plus, plants are obviously the best way to accessorize a windowsill.

Some plants really thrive in direct light and can't seem to get enough, but others can have a bad reaction. If you start to see burned spots or bleached leaves, this could mean that your plant doesn’t want as much sun as they're getting. You can either introduce a sheer curtain (BTW most curtains are "sheer" if they're not super heavy or black-out) or move the plant a bit further away from the window to help them recover.

Bright, Indirect Light

Quick Facts:

  • For the vast majority of houseplants
  • Partial, soft, filtered, dappled, and indirect are other names for this type of light
  • Found by both west and east-facing windows and a few feet in from south-facing windows or those with a sheer curtain

Bright, indirect light is what a vast majority of houseplants prefer. It also happens to be the most misunderstood lighting term. Typical, right?

Bright, indirect light is easier to understand when you take it back to a plant's natural habitat. A plant that needs this lighting adapted to an environment where something is blocking the direct sun. For example, plants that grow on forest floors or climb trees. They benefit from the sun; they may even enjoy full sun at certain times of the day. But mostly, they are shaded by the massive trees that tower over them.

So when translating that to our homes, you'll want to look for areas of the house that still get quite a generous amount of light throughout the day, just not 100 percent of the most intense light all day long.

Indeed, if you think about it in percentages with a south-facing window getting the most intense light, then east and west-facing get about 60 percent of that. And north-facing only receive about 20 percent.

When looking for bright, indirect light, a good place to start is close to an unobstructed east or west-facing window. But you can also easily moderate the direct light of a south-facing window with a sheer curtain or by moving the plant further away from the source (aim for around five feet or so if there's nothing obstructing the light).

Bright indirect light plants are a lot like us—we want a little vitamin D, but too much, and we could get a little crispy!

North-facing windows do not get enough light for plants that need bright indirect light. If you’re desperate to have your plant in a room that only has a north-facing window, you'll have to bring in some backup (artificial light) to make your plant happy.

Low Light or Partial Shade

Quick Facts:

  • Minimal natural lighting, but still light coming through
  • Many plants are low light tolerant, but that doesn’t mean it's the best light for them

Low light can be found at north-facing windows or further away from windows facing other cardinal directions. A good rule of thumb is if you can’t comfortably read a book on a sunny day, you're dealing with a low light situation.

Low light plants can be great for bathrooms with small or even no windows – as some can survive off of artificial light alone. They also can brighten up a garage or basement. Or they can bring a little life to an otherwise sad corner in your home.

Just remember: Low light ~tolerance~ means they can survive, but they certainly won’t thrive.

If you put a low light tolerant plant in a dark, dusty corner that never sees the light of day, then they won’t be growing much, if at all. That’s because a low light tolerant plant goes into an extended state of dormancy. They essentially stop growing or make minimal changes in growth. This can be a great thing if you like how the plant looks and don’t want them to change much. However, if you want the plant to grow, you may need to give them a little more of the good stuff (light).

A Different Perspective: Light by Window Direction

So now we're clear on what those care instructions mean when they refer to light requirements. We also understand where to find that light in our homes. But it can be helpful to understand how the sun moves over the course of a day and through the seasons to really seal the deal.

The sun follows a path, also known as a day arc, which impacts a plant’s livelihood. As shown in the diagram below, the sun’s path is oriented to the south, along an east-west arc, which is higher in the summer and slants lower in the winter.

With this in mind, it's easier to understand why south-facing windows offer your plants the brightest light for the longest portion of the day. While your north-facing windows offer the lowest, most diffuse light. And continuing around, the east gives you the morning sun, which is a bit less intense than the hot afternoon sun of the west.

Keep in mind, these guidelines assume your windows directly face each cardinal direction. Make sure to pull out a compass (by which we mean your phone; we don’t expect you to have a compass in your pocket) and verify which direction your windows face. It could very well be that you have south-west or south-east windows, and you’ll need to combine some of these guidelines.

Oh, we also based this guide on the day arc of the northern hemisphere. Sorry, southern hemisphere dwellers—you’ll have to switch it around.

South-Facing Windows

In the summer, south-facing windows can really drench your plants with direct light. If you don’t want to limit the space to succulents and cacti, add a sheer curtain to create bright, indirect light. You can also place plants further away from the window, about five feet or so, to get the milder light so many houseplants desire.

One thing to remember during the summer is that all that direct light also comes with increased temperatures. Most houseplants, except for desert cacti, may not easily tolerate these increased temperatures without a little work.

Just like the hot summer sun easily dehydrates us, the soil of our plants dries out faster when temperatures rise.

You'll have to be mindful of your watering frequency and increase as needed.

West-Facing Windows

The sun sets in the West, so near sunset, it will shine through these windows. It’s not quite as strong as the sun at its peak, but it's hot and strong enough to be considered direct light for these few hours. Taking the whole day into consideration, west-facing windows fulfill bright, indirect light requirements.

Another way of thinking about it is that a west-facing window provides something between direct and low light throughout the day with the intensity increasing as the sun sets, but only briefly.

East-Facing Windows

As the sun rises in the morning, rays of sunshine will stream through an east-facing window. But the sun hasn't had a chance to really heat anything up, so it's generally a bit milder than when it sets in the west. A lot of houseplants love these windows! East-facing windows can meet the requirements for bright, indirect light plants, but with blinds or curtains, they may be best for low light plants.

If you close your blinds at night and are late to wake in the morning, make sure to take that into account as you are planning plant placement.

North-Facing Windows

The sunlight never comes directly through north-facing windows. While this may not sound like a great place for plants, it still provides consistent low light throughout the day. This makes sense for plants that can survive on minimal light. Or, as we said earlier, if you’re loving how your low light tolerant plant looks, you can them to this area to preserve their size.

One thing to keep in mind with these windows is that they tend to be colder in the winter than any other. Keep an eye on the temperature sensitivity of your plants before you place them too close to a north-facing window.

It’s Not Just the Direction!

In addition to the cardinal direction of a window, there are other things to keep in mind when contemplating where to place a new addition to the plant family. It can’t be that simple, right?

To identify the other things that contribute to light, it’s helpful to look outside the window and around it. Do you live next to a building that towers way over yours and blocks out the sun? That changes things.

Even something as simple as an awning, a big tree, or roof overhang can have an impact on the available light.

Do you have privacy frosting or maybe an energy-saving coating on your window? That also changes things. Are there blinds or shades that you often forget to open? Another consideration.

How to Measure Light

Alright, you've made it this far and we've hammered home the concepts of how light changes depending on the orientation of your space and distance from windows. But how can you be sure that you are choosing the right spot? Are there ways you can measure it?

Absolutely! There are multiple options for measuring the light in your house. Make sure you are taking measurements numerous times throughout the day, and even multiple days in a row, as conditions can change depending on the weather or season.

Shadow Test

Want to do the test without leaving the house or buying extra supplies? Try the shadow test! You can do it in a couple of different ways:

Option 1: Become the plant… or at least stand in the place you want your plant to be. Then, all you have to do is check your shadow.

Option 2: You can do the “hand test” by putting a piece of paper, or an open book, where you want your plant to be and hold your hand above it.

Either way, the concept is the same. If you see a crisp, well-defined shadow, that means you’re working with direct light. When the shadow is defined but a bit fuzzy and not so crystal-clear, that means you have bright, indirect light. And finally, when there’s barely a shadow cast (but still something), that indicates low light. No shadow means it’s not a great place for a plant. Simple enough, right?

Light Meter

If you want to be 100 percent sure, you can use the precise measurement option. Light meters will let you know precisely how much light is present, using a measurement called foot-candles.

There is a huge range of light meters on the market. Photographers often need these tools to assess the light for their cameras. But you don't have to get a super fancy one, a simple one without all the bells and whistles will do.

Your light meter will measure the light in foot-candles. Curious to know what in the world a foot-candle is? Well, this measurement has been around for longer than electricity.

Back in the day when the main light source was a candle, this unit of measurement emerged to define the amount of light a candle would spread across one square foot.

Anyway, how does this apply to houseplants? The ranges of foot-candles can accurately measure the type of light your plant is receiving. You'll want to place the measuring device right about where the leaves of your plant will be and use these ranges:

  • 50 to 250 foot-candles: Low light
  • 250 to 1,000 foot-candles: Low to medium light
  • 1,000 to 2,000 foot-candles: Bright, indirect light
  • 2,000-5,000 foot-candles: Direct light

For comparison—outside in full-blown, unobstructed sun, the foot-candle measurement would be about 10,000 foot-candles!

Artificial Light: When You Don’t Have Enough of the Real Stuff

Do you live in a place that doesn’t have that many windows? Or are all your windows currently occupied by other plant babies? There are options for you, too. While you might worry about artificial lighting because it’s not as good as the "real stuff," sometimes it's necessary to supplement the light you have, especially during the winter months.

There’s a vast world of artificial lighting options out there, but they are not the same as the bulbs you already have at home. The problem with traditional light bulbs is that they don’t deliver the full-color spectrum plants need to photosynthesize. Plants require mostly blue and red light, but some need infrared light as well (especially for flowering). Also, most regular light bulbs (incandescent) emit heat, which isn’t great for houseplants.

We’ll focus on the three main options and what they can do for your plants.

LED Grow Lights

No, unfortunately, this is not the same as the LED lights you may already own. LED grow lights are specialized for a plant's needs. However, there are options available to do a one-for-one swap with one of your regular bulbs—lighting up the room for both you and your plants!

These lights have better energy usage than the other options, so they'll last longer. But they may be less effective than others if you are specifically looking to get your plant to flower or fruit (not super common for houseplants).

Fluorescent

Fluorescent grow lights are the most cost-efficient of the three types, depending on your setup. These grow lights provide a fuller spectrum of light than a normal fluorescent bulb, simulating something closer to natural light to help your plants grow.

High-Intensity Discharge (HID)

This light source has a lot of options. There are three main types of HID grow lights:

  • High-Pressure Sodium (HPS)
  • Metal Halide (MH)
  • Ceramic Metal Halide (CMH)

Each has its specific use. For example, HPS is made for when a plant is at its flowering stage. When plants are in vegetative stages, MH is used. CMH has a broader spectrum, so it serves as an all-purpose light.

No matter which type of grow light you choose, your plants will appreciate the boost during the winter months or if your home has much less than ideal lighting.

Can I Move My Plant?

Caring for a plant is a perpetual learning experience. If your plant seems stressed in the condition they're in or just not thriving as much as you’d like, you can move them! But try not to move the plant too far all at once.

Unless they're showing an unmistakable sign of light deficiency, be kind to your plant, and only move them a little bit at a time.

Plants usually don’t like extreme change, so try to be sensitive to that in your experimentation phase. Examine how they do in their new spot for a couple of days, and if there’s no improvement, move the plant again. Look out for signs like the plant’s leaves stretching or twisting around to get more sun. If you see that, help a plant out! Move them a little closer to the light until they're happy. Feel free to keep experimenting and watch the signs your plant is giving you.

Now You’re the Expert!

Hopefully, this article cleared up a lot of questions and misconceptions about lighting for houseplants. It can seem overwhelming at first, but once you understand the basic parameters you're working with, finding your plant's happy place won't be quite so mysterious.

And now that you know exactly how to figure out what type of light your space has to offer, it’s time to do a walk around the house, investigate lighting levels, and get your hands on some more plants!

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