How to Determine Sunlight Levels for Houseplants

Too much or too little light may stress a plant rapidly, making it more susceptible to disease, pests, and early mortality. Fortunately, the majority of plants are labeled with their light requirements, such as full sun or moderate shade. However, determining the right illumination for your plant may require trial and error, so you will need to keep a careful eye on it.

Typically, it is simpler to assess the quantity of sun in your yard than indoors. Outdoors, it is evident where the shade is and where the light is shining straight, and indoor lighting is more modest. To determine if a houseplant will thrive in your environment, it is essential to be aware of the various kinds of light available.

Light

Light (Artificial Light or Natural Light) is one of the six most important ingredients plants need to do well. The others are water (You can use a moisture meter to determine if your houseplant is getting enough water), humidity, healthy soil, warm temperatures, and nutrients. The key is to have the right balance for each of these things. Too much, and most plants will suffer. Too little of any of these, and plants cannot survive.

Light is essential for plants because it helps them to make food through photosynthesis. Photosynthesis is the process plants use to convert light into energy they can use to grow. Plants need light in order to produce the energy they need to grow. However, too much light can be harmful to plants.

It can cause them to lose moisture and become stressed. When this happens, they can become weak and susceptible to disease. Too little light can also be harmful to plants, and they will not be able to produce enough food and will not grow as well.

The right amount of light is different for each plant species and depends on factors such as the time of year and the plant’s growth stage. Most plants have the best light conditions between full sun and partial shade. By providing the right amount of light, you will help your plants to grow strong and healthy.

Light Levels for Plants Explained

Instead of considering where your indoor plants would look and fit best in interior design, you must consider their requirements. This is decided by the plant’s native environment, which is the defining element for what each plant needs to live and grow.

The ideal light intensity for plants is crucial since too much or too little light may be detrimental. Light is required for photosynthesis, and the optimal light levels for plants must be researched since they vary greatly from plant to plant. Plants need light to undergo a chemical process that converts carbon dioxide, water, and light into sugars. 

While every plant needs sunlight to grow, different types of plants have evolved to thrive in different environments. Some plants need full sun, while others do well in partial shade. By understanding the natural habitat of a plant, you can provide the right amount of light for it to prosper indoors.

To get started, take a look at some of the most popular houseplants and see where they come from. With a little research, you can create a happy and healthy home for your plants—and yourself.

Bright Direct Light

When choosing a spot for your plants, be sure to take into account how much light they will need to thrive. Most plants thrive at least five to six hours of direct sun light each day, although some can get by with less. The windows facing south and west will get the most direct sunlight, so these are usually the best choices for plant placement.

Keep in mind that the amount of sunlight available decreases in the fall and winter, so you may need to supplement with artificial light if your plants are not getting enough sun. 2000-5000 foot candles of light are considered bright direct light, so consider this when choosing a location for your plants.

20 Best Plants for High Light

1. Jade Plant (Crassula argentea)
2. Gardenia (Gardenia jasminoides
3. African Milk Bush (Euphorbia trigona)
4. Croton (Codiaeum variegatum)
5. Bird of Paradise (Strelitzia)
6. Aloe Vera (Aloe barbadensis)
7. Echeveria
8. Areca Palm (Dypsis lutescens)
9. Fiddle-Leaf Fig (Ficus lyrate)
10. String of Pearls (Senecio rowleyanus)
11. Sago Palm (Cycas revoluta)
12. Geranium (Pelargonium)
13. Yucca Plant (Yucca gigantea)
14. Papyrus (Cyperus papyrus)
15. Ponytail Palm (Beaucarnea recurvata)
16. Jasmine 
17. Money Tree (Pachira Aquatica)
18. Snake Plant (Sansevieria trifasciata)
19. Hibiscus (Hibiscus rosa-Sinensis)
20. Dragon Tree (Dracaena Draco)

Bright Indirect Light

Bright indirect light is defined as having a luminous intensity between 1000 and 2000-foot candles. With bright indirect light, shadows may be clearly defined. Bright indirect light is the most difficult to understand when researching plant light levels because it doesn’t fall on your plant’s leaves directly.

Instead, it bounces off of something first and then falls on something else. However, this type of light is still important for your plant’s growth. Bright indirect light helps to promote photosynthesis, which is essential for your plant to create food. It also helps to support the development of strong roots and stems. As a result, Bright indirect light is important to a plant’s overall health.

10 Best Plants for Indirect Light

1. Kentia palm
2. African Violet (Saintpaulia)
3. English Ivy (Hedera helix)
4. White Bird of Paradise
5. Chinese Evergreen (Aglaonema) 
6. Peace Lily (Spathiphyllum)
7. Maidenhair Fern (Adiantum) 
8. Monstera adansonii
9. Peperomia hope
10. Begonia maculata

Medium Light

Medium-light is defined as having a luminous intensity between 250 and 1000, and this means that the light is bright but does not come from a direct source. When a plant is situated a short distance from a window, it is said to get medium-light illumination levels.

A foot-candle reading between 250 and 1000 is regarded to be of medium-light for plants. This level of brightness is perfect for plants that need some light but cannot tolerate direct sunlight.

7 Best Plants for Medium Light Plants

1. Spathiphyllum
2. African Violet
3. Begonias
4. Boston Fern (Nephrolepis)
5. Croton
6. Dumb cane
7. Moth Orchid

Low Light

Conditions considered to have a low light for plants range from 50 to 250-foot candles. While this may seem like a small difference, it makes a world of difference for plants. In low light conditions, plants are unable to photosynthesize as efficiently, and as a result, they grow more slowly and produce fewer flowers.

For this reason, most houseplants require at least some direct sun light in order to thrive. However, there are a few exceptions that are able to prosper in lower light levels. These plants have evolved to be more resilient and are able to make the most of the available light. As a result, they are perfect for adding a splash of green to dark corners of the home.

7 Best Plants for Low Light

1. Snake plant (Dracaena trifasciata)
2. Dracaena
3. ZZ Plant
4. Spider plant
5. Lucky Bamboo (Dracaena sanderiana)
6. Arrowhead plant
7. Heart-leaf philodendron

How to Measure Light?

In addition to understanding the concept of bright indirect light, it is extremely useful to know how to test for it. Here, we will demonstrate two ways to detect if your plant receives indirect light and its intensity.

Shadow Technique

The shadow technique is useful for determining whether a plant is receiving direct or indirect sunlight since it enables you to estimate the kind of sunlight based on the appearance of the plant’s shadow.

A shadow with finely defined edges indicates direct lighting, and this is due to the fact that the light strikes the plant directly and casts a perfect shadow.

Weak shadows with imprecise or hazy edges indicate indirect light since the sun is not striking the plant directly and so is unable to cast a precisely defined shadow.

A shadow that is scarcely visible suggests poor light. There is still enough light to cast a shadow, but it is quite feeble.

These are important guidelines to bear in mind while working with plants. If you want a more precise measurement of the quantity of light your plant is getting, you should use a light meter, which we shall discuss in the next section.

Light Meter

Foot candles are the unit of measurement used by a light meter to determine the intensity of the light that is presently present. The measurement varies depending on various conditions, such as the time of day, whether you are inside or outside, and the direction the meter is pointing.

Bright indirect light ranges between 800 and 2000-foot candles and fluctuates depending on the placement of the plant. However, if you combine the information from the light meter with your knowledge of what constitutes indirect light, you should be able to get a full picture of the amount of light your plant is receiving.

What influences Natural Light Levels?

Natural light levels are influenced by many factors, including seasons, time of day, weather patterns, and distance from the sun. Winter months have shorter days and longer nights, so less natural light is available. This is why it’s important to situate your plant near a window during this time.

Time of day also impacts natural light levels; for example, the midday sun is much brighter than the early morning or evening sun. Weather patterns can also affect natural light; for example, if it’s cloudy or raining outside, less natural light will come in.

Finally, the distance from the sun also plays a role in natural light levels; the closer your plant is to a window, the more natural light it will receive. All of these factors should be considered when determining how much bright indirect light your plant needs.

How to Increase or Decrease Light Levels?

You can increase or decrease natural light levels by placing your plants. If you want to provide more light for your plants, you should relocate them to a location that is free of obstructions. You can also purchase an LED grow light to provide your plant with the supplemental light required.

In addition, you can also control the amount of light that is present by using window treatments, such as blinds or curtains. You can let in more or less light as needed by opening or closing these window treatments. As a result, the placement of your plants significantly impacts the light they get.

Windows

The windows in your home can have a big impact on the placement of your houseplants. As the sun rises in the east and sets in the West, the amount of sunlight that windows receive varies depending on their orientation.

Windows that face east will get brilliant direct sun light for a couple of hours in the morning, while windows that face south will receive strong direct sunlight for multiple hours in the afternoon.

As a result, it is important to position your houseplants in front of the appropriate window to ensure that they receive the right amount of light.

North Facing Windows

North-facing windows don’t get as much direct sunlight as the other windows, which indicates a restricted quantity of light available to the plants. On the other hand, this fact does not necessarily imply that plants cannot be grown in these windows.

Many types of plants, including some found growing in jungles, can survive with just a little amount of light and flourish well even in windows facing north.

East-Facing Windows

East-facing windows let in an extremely large quantity of brilliant indirect light. The first few hours of daylight may be seen via windows that face east in the morning. Many plant species can adapt to this form of light since it occurs in the morning when the sun’s intensity is lower than in the afternoon.

East-facing windows get a significant quantity of ambient indirect light in the afternoon. Temperatures tend to be a little bit lower while looking out an east-facing window.

Since this is typically where the brightest and most diffuse light is found in a home, east-facing windows provide an ideal environment for many different kinds of plants, as they offer both bright indirect light and cooler temperatures. As a result, these windows are often perfect for growing healthy and attractive houseplants.

South Facing Windows

South-facing windows receive direct sunlight throughout the day, making them ideal for plants that require a lot of light. However, it’s important to remember that the windows will intensify the light, so you must be careful not to overexpose your plants.

Leaf burn, brown patches, and holes in leaves are all symptoms of excessive sun exposure. If you need to shade your plants, you can do so by putting drapes or fabric screens in front of the windows, and this will reduce the amount of light that reaches the leaves and transform the direct light into indirect light.

South-facing windows can be a great asset for your plants, but you must be mindful of the amount of light they receive.

West Facing Windows

West-facing windows are ideal for plants that need lots of direct sunlight or thrive in the afternoon sun. In the morning, the sun rises in the east and casts very little light onto west-facing windows. However, as the day progresses and the sun moves West, the amount of light that enters through west-facing windows gradually increases.

This makes west-facing windows perfect for plants that require high levels of direct sunlight or do best in the late afternoon sun. So, if you’re looking to give your plants the best chance to grow and thrive, be sure to place them in a west-facing window.

How Do I Know If My Plants Are Getting Enough Light?

Because no two plants are exactly the same, not all plants exhibit the same signs of being exposed to excessive or inadequate light. If you’re having problems with a certain plant, look for a site that’s only focused on that species. Plants that are exposed to too much or too little light exhibit a variety of symptoms.

Too Much Light

Burnt leaves are one of the most obvious signs that a plant is getting too much light. Brown stains and burnt leaves are what this seems to be. Avoid burning your plants by immediately moving them to a reduced light environment.

Insufficient Light

Photosynthetic energy isn’t reaching the plant’s cells fast enough, resulting in stunted growth and development. When this happens, the plant becomes weakened and drooping, with fewer leaves and blooms than it should.

You may help your plant seem better by moving it to a location that gets more sunlight. Make sure you know exactly how much light each plant species need.

Determine Sunlight Levels for Houseplants – FAQ

How do I know if my plant is getting enough direct light?

To determine how much light your indoor plants need, you can measure light by the number of hours per day that the plant is exposed to direct sunlight. The average amount of sun per day that a plant need is between four and six hours.

What are the signs when a plant is getting too much direct light?

If a plant is getting too much direct light, the leaves will begin to turn brown and crispy. The plant may also become stunted in growth.

How do I determine how much light a plant needs?

To determine how much light a plant needs, you need to research the plant species and find out how much light it needs to thrive. Once you know the plant’s requirements, you can then provide the appropriate amount of light.

Which window will location receive the most bright light for plants?

A sunny southern or western-facing window will receive the most bright light for plants.

Where can I buy a light meter for my house plants?

You can find light meters for your house plants at most hardware stores or online.