How Much Light Do Calathea Plants Need? (Calathea Plant Light Requirements)

A Calathea will remain beautiful if it receives a good amount of light. Creating a proper balance of light for Calatheas might seem challenging. On the one hand, these plants are sensitive to sunburn, and on the other hand, they will fail to reach their full potentials without good quality light.

But how much light do calathea plants need? Let’s find out.

Calathea plant will need at least 8 to 10 hours of medium indirect light along with 8 hours of darkness. This balance of light and darkness will make them thrive. Calatheas leaves turn yellow and brown when they are exposed to bright or direct sunlight. So, keep them in medium lighting conditions.

If you are a beginner at growing a Calathea plant, this article will let you know the light requirements of a Calathea plant. We will also include some tips to create an ideal environment with suitable lighting conditions for the Calathea plant. 

How much sunlight does a Calathea need?

In their natural habitat, Calathea grows under the shade of tall rainforest trees. 

These trees protect them from the direct, scorching rays of the sun. It is the reason most growers prefer calling them to be low-light plants.

Although Calatheas should not be exposed to direct sun, it doesn’t mean that you should keep them under full shade. It is a bit deceiving to declare them low light plants.

Calathea needs medium bright, indirect sunlight for long 8 to 10 hours to survive and thrive. It will also need 8 hours of darkness. 

Calatheas are habituated to grow under a considerable amount of light, dappled and indirect.

Calatheas will be able to tolerate medium-light to some extent, but neither excessive nor low light. If Calatheas don’t receive a good amount of light, it will affect their growth, development, and maturity.

The best way to provide the exact amount of light to the Calathea plants is to read and learn about their natural environment and mimic the same environment for your Calathea while growing indoors.

What are the light requirements of Calathea?

For providing the right amount of light to your Calathea, you need to look up three essential factors – intensity, duration, and quality.

Light intensity

This tells how much light Calathea would be able to tolerate.

Calathea will need the right amount of sunlight for photosynthesis and to produce enough energy for good growth. 

These plants in their native land grow best under indirect sunlight, being protected from the harsh sun by the tall rainforest trees. So, exposing them to direct sunlight can result in scorched leaves.

To be specific, Calathea will require and tolerate medium bright indirect light with the intensity of 10,000 lux or 1,000-foot-candles.

To understand if you are providing the exact light intensity, you can measure it. For measuring, you can use a light meter if you want. 

There is another natural method that you can opt for without any device.

• Take white paper.
• Now, hold your hand 8 to 10 inches away from that white paper. Do this in the place where you want to keep your plant. 
• If you notice only blurred outlines of your hand, then the intensity level is 10,000 to 15,000 lux. It is perfect for the Calathea.

However, using a measuring device can give you the exact intensity level.

You can measure any location in your room. Generally, you can find the correct intensity for Calathea near a south-facing window. This direction gives the ideal medium bright, indirect sunlight. 

A west-facing window receives too intense sunlight. But you can select this direction for your Calathea by using curtains or Venetian blinds to create a filter and decrease the intensity. 

But a north-facing window will provide insufficient sunlight.

Light duration

The following important factor is the duration, which tells you how long you should provide light to your Calathea.

Calatheas will need 8 to 10 hours of medium bright, indirect sunlight daily without getting exposed to direct sun. 

During the winters, the intensity reduces, so you will need to use the grow lights to match this exact duration.

When you use these artificial lights, ensure that you give them 16 hours of light if the artificial medium is the only light source. 

The duration of light should be accompanied by 8 hours of darkness daily.

The Calathea will need darkness for respiration, through which they distribute the energy produced at the time of photosynthesis for growth.

Light quality

The last important factor which needs to be considered is the quality of the light. This explains the quantity of blue light, green light, red light, and far-red light coming out from the used light source for Calathea.

The red light spectrum encourages the Calathea plant for good photosynthesis. The blue light spectrum promotes rich color in the variegations of your Calathea plant.

Sometimes, to protect your plant from the direct sun rays, you can use window films. They will block the ultraviolet rays and not the red and blue light needed by the plant. They are thus safe to utilize.

Can calathea tolerate low light?

Calathea belongs to the tropical areas of South America. Being tropical plants, they can grow and survive under low light conditions to some extent. But excessive low light can create problems in them.

• With low light conditions, Calathea will have stunted growth in them.
• They might even stop growing if they don’t get enough light.
• Calatheas, also known as Prayer plants, fold their leaves during the night. So, when they are not getting enough light, they stop praying, which means they don’t fold.
• They will have long, leggy stems, growing towards sunlight. It indicates that your plant is constantly trying to reach out for more sunlight.
• The plant doesn’t absorb water from the soil, which can cause overwatering issues.

How to enhance the light conditions for Calathea?

Relocate your Calathea plant to a much brighter place than the existing ones. 

North-facing windows are good, but it does not give much light, especially during the winters. The intensity doesn’t match with the plant’s actual needs.

You can place them to an east-facing window or south-facing window. Do not suddenly change the position. 

Make the change gradually; for example, keep the plant in the new location for 1-2 hours on the first day and bring it back to its old place. Then increase with a few more hours on the second day. Like this, slowly increase the hours.

During the cloudy climate, the sunlight is not much available. In such a case, grow lights will save your plant from low light conditions.

Try using LED lights for your Calathea. They are quite energetic and won’t even scorch your plant.

If your plant is in a location where the surrounding is dim, Calathea will need light for 12 hours or more. Otherwise, 6 to 8 hours of light would be enough. 

A grow light with a timer would be ideal as you won’t have to give extra effort behind switching it on or off. You can set a timer on when to switch on or off, which will do the job.

Do not place your grow lights too close to the plant. Maintain a distance of at least 12 to 30 inches between light and plant from the top.

Is my calathea getting too much light?

Just like low light can affect the health of the Calathea plant similarly, excess light will harm the plant’s health.

In their native land, Calathea grows under tall rainforest plants, where they receive indirect sunlight. Thus, Calathea won’t be able to tolerate the sun’s direct, harsh and scorching rays.

• The plant will lose its color and charm. The patterns of the leaves will fade. 
• The tips of the leaves will turn dry and crispy. This can also be a sign of low humidity. So inspect well before treating.
• The tips will sometimes turn brown and die.
• The leaves will have signs of sunburns on the surface.

How to revive a scorched Calathea and prevent excess light from reaching it?

When you notice that your Calathea shows signs of sunburn, relocate it to a place with indirect light for some weeks. You might need to prune off the affected leaves.

After relocating, if its condition improves, the plant will start reviving and will soon recover. 

Be careful while pruning. Do not harm healthy tissues as they will continue to photosynthesize and provide the energy your plant will require to produce new leaves.

Also read: Can Indoor Plants Get Too Much Light?

Finding the right location

While relocating your plant to provide it with the right amount of light, it is crucial to understand which direction window will give it ample light for survival.

The first thing you should do while choosing an ideal spot is: measure the light intensity and duration that the direction gets.

There is always the option of grow lights. But sunlight is also essential. So it is better to find the right direction for the placement of your Calathea.

If you stay in the northern hemisphere, the sun remains in the southern skies most of the time. 

A room with a window in the south direction will give a lot of direct and intense sunlight than any other direction.

If you are placing your Calathea in this direction, its leaves might burn. 

However, you can place the Calathea by keeping a distance of at least 4-6 feet in between the plant and window. It will save your plant from the scorching heat of the sun.

A west-facing window will give direct sun rays but only for a few hours. These few hours would be in the mid-to-late afternoon when the temperatures are at their highest peak. 

High temperatures and direct sunlight together can cause sunburn in the leaves and damage their health. So, if you are placing your plant in this direction, keep it 4-6 feet away from the window.

Now, coming to the east direction, it is suitable for the Calatheas. This direction will give bright direct sun rays during the coolest time of the day. Then it will shift to producing indirect light once the air heats up.

Placing the Calathea near an east-facing window will reduce the risk of sunburn in the plant. However, this direction will not give your plant enough light for reaching its full potential or good growth.

So, these are some possibilities of sunlight from different directions. It might vary if you are living in different hemispheres. 

You will have to observe your plant’s growth and then relocate your plant to the place where it can get the right amount of sunlight.

Filtered sunlight

It is not always possible to have east or north-facing windows to place the Calathea plant. These two are pretty ideal because they give an indirect and medium bright light to your plant. 

But the other two directions, south, and west give harsh sunlight.

So, if you have a window that receives harsh sun rays, one solution is keeping a distance between the window and plant. Another way is to use filtered light. 

Filtered light will also supply your plant with indirect sunlight. Filtered light means you will have to create a barrier, like folding paper screens, window films, sheer curtains, or Venetian blinds. 

Attach these in your window to reduce the intensity of sunlight.

Curtains made from thin, fabric linen, lace, or chiffon will work well. Ensure that they don’t block the light.

Venetian blinds or vertical blinds are left partially open. They will also work for giving your Calathea indirect light.

Tips to better lighting condition

There are a few more tips to improve lighting conditions for your Calathea.

Mirror to reflect light

If the window of your room is getting too much sun, and you don’t want to risk placing your plant near it, and you don’t even have protection barriers, you can try an alternate.

If your Calathea is placed in a dim or dark location, you can use a mirror to reflect the sunlight to allow the light to reach your plant.

When the sun comes in and touches the mirror, the sunlight will reflect and reach your Calathea. It will give your Calathea the right amount and intensity of sunlight.

Rotate the plant towards the light source

You might notice that one side of the Calathea plant is growing well while the other side is not in good health. It happens when you have not positioned your plant correctly. 

Maybe one side is receiving good light, and another side is not getting any light.

In this case, you must rotate your plant towards the light, especially the not well-grown part.

Along with this, you will also have to alter the watering routine to maintain and promote balanced growth.

Final thoughts

Keeping the Calathea plant strong and healthy will require proper care and attention towards the plant. Along with the right amount of light, you should also provide proper watering, temperature, and humidity in a balanced way.

You might make some mistakes, but identifying them on time and taking steps can help revive the plant within a few weeks. It is all about trial and error. It will make you understand the best methods to provide Calathea with the best care.

As providing the exact light to the Calathea might need frequent relocating, you should not change its position suddenly. Do it slowly, step by step, gradually increase the timing of light exposure. This will save Calathea from a shock.

Also read: How much sun do indoor plants need? (With 25 Examples)

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Source: NCBI, University of Florida, Wikipedia,  Growing Indoor Plants with Success, Agriculture, and Natural Resources, University of California, Missouri Botanical Garden.