A Monstera plant, also known as a Swiss Cheese plant, is a tropical plant from the rainforests of Mexico and South America. It grows under the rainforest canopy where it receives indirect light through the foliage. While conditions on the forest floor may not be in direct light, indirect sunlight often penetrates the canopy providing soft indirect sunlight to Monsteras. When grown inside as houseplants, Monsteras need medium to bright indirect for several hours a day.
How much light does a Monstera need?
Light for plants is measured in two ways: Light intensity and the duration of light. Light intensity refers to how bright the light is while light duration refers to how long your plant is exposed to sunlight. Both the intensity and duration of light is important to growing healthy Monstera plants.
What is Light Intensity?
Light intensity is referred to in several ways. You may see it called low, medium, or bright light, or you may see terms like indirect light, bright indirect light, direct bright light, direct sunlight, or even full sun. Understanding terms used to describe the intensity of light will help you choose the best lighting for your Monstera plants.
Low light means there is very little natural light reaching your plants. If you hold your hand 12 inches from the plant, between the plant and the light source, your hand will cast a faint shadow (or no shadow at all).
Medium light means your plant receives some light from the sun but is not in direct sunlight. With the shadow test, you will see a light-colored shadow with a fuzzy outline.
Bright light means the area around your plant is brightly lit and will cast a more defined shadow, but it does not receive direct sunlight on the leaves of your plants.
Direct sunlight means that the sun's rays shine directly on the foliage of your plants.
What is Duration of Light?
The duration of light refers to the amount of time your plant receives sunlight or natural light each day. This is typically measured in hours. But there are some important things to note about the duration of light for plants.
- The number of hours of light exposure do not need to be consecutive. Sun or light exposure can be a combination of shorter bouts of exposure. For example, if your Monstera plant receives 3 hours of bright indirect light from an eastern window in the morning and 3 hours of afternoon sun from another window in the room, it receives 6 hours of light.
- Not all light is the same. Exposure to 2 to 3 hours of bright filtered light from a western or southern window will provide your plants with more sunlight than an equal amount of low light from a northern window.
What type of light does a Monstera plant need?
Monsteras need bright light but do not tolerate direct sunlight. They can survive in low light, but their growth will be inhibited. To grow a striking Monstera plant with the lacy leaves and the coloration you adore, you need to provide it with good light.
How many hours of light does a Monstera need?
Typically, Monsteras need 5 to 8 hours of bright indirect light a day to thrive. Variegated varieties, like the Thai Constellation Monstera deliciosa or Variegatta Monstera deliciosa, need more light to bring out their beautiful coloration.
The variegated portion of Monstera foliage lacks the chlorophyll necessary to convert the sun's energy to usable energy for the plants. They rely on the green portions of the leaves to do all the work. Variegated varieties will lose their dramatic whites and creams if they do not receive enough sunlight. Your Monstera's new leaves will be solid green to compensate for the lack of light.
How much light your Monstera plants need depends, in part, on the specific variety you are growing. It also depends on the quality of light it receives. One or two hours of quality light may outweigh several hours of exposure to weak light.
How do the seasons affect the quality of light?
The sun is higher in the sky during the spring and summer creating high-intensity light. During the fall and winter when the sun remains lower in the sky, the sun's rays are less intense. If you live in the northern part of the U.S. your Monstera plants may struggle from the lack of light in the winter or may need to be moved to a location that receives more light.
Likewise, plants that thrive in the winter near a west facing or south facing window may need to be moved to less light when spring and summer arrive.
What are the dangers of too much light?
Monstera plants are tropical plants and will suffer from too much direct sunlight. In fact, their leaves will burn if they are exposed to direct sunlight from the afternoon sun. But too much light has other effects too.
- Excessive Drying: Direct sunlight can cause the pot to overheat and the soil to dry excessively. This causes stress to your Monstera as it needs evenly moist soil to thrive.
- Lack of Humidity: Direct sunlight doesn't just dry out the soil, it dries out the air too. Placing your Monstera in direct sunlight is an invitation to problems with low humidity.
- Browning Leaves: The combination of low humidity and dry soil from too much sunlight may cause your Monstera leaves to turn brown and get crispy along the edges.
- Leaf Scald: Tender Monstera leaves have adapted to absorbing energy from bright indirect sunlight. As a rainforest plant, Monstera react to bright sunlight by burning or scalding of the leaves. They typically look pale or white and will lose their ability to perform photosynthesis, a process necessary for healthy growth.
Can monstera grow in low light?
Some Monsteras can grow in relatively low light, but that doesn't mean they will be a thriving plant in low light. Monstera need enough light for healthy leaf growth, to develop their beautiful fenestrations, and to create striking variegated leaves.
However, Monstera plants do not need to be grown in a sunny window and are perfectly happy with light conditions where they receive indirect bright light from a south facing window located across the room. They also like light from a west facing window as long as they are far enough away to avoid direct sunlight.
What are the dangers of too little light?
A Monstera plant will suffer from lighting conditions where its light requirements are not met. Like other plants grown indoors, it depends on you to provide it with the lighting conditions it needs to promote new growth and flourish. That means a Monstera plant needs light from a bright window to perform photosynthesis.
How much sunlight your Monstera gets determines how quickly it grows, whether the leaves produce the abundant fenestrations giving the leaves a lacy appearance, and to develop the variegation in variegated varieties. Too little light can cause a number of issues.
A monstera plant grown in low light conditions will show its displeasure with leggy growth. The stems elongate leaving long expanses of the stem between leaves as the plant attempts to stretch for the light. This can leave your plant looking sparse as it climbs your moss pole.
Poorly Developed Aerial Roots
Monstera, like other tropical plants, produces aerial roots that are capable of absorbing both moisture and nutrients from the air. The aerial roots also cling to your moss pole or moss-covered totem to help the plant climb. It needs good lighting conditions for the healthy growth of the aerial roots, too. Too little light may make the aerial roots weak and poorly developed comprising your Monsters plant's ability to climb.
If your Monstera is too far from its light source or the light conditions are too low it will likely produce small leaves. Most plants will remain immature for years producing small green leaves.
Lack of Variegation
Variegated varieties of Monstera are the result of a genetic mutation that causes the lack of chlorophyll in the light or variegated parts of the leaf. That means the green parts of the leaf need to do all the work of performing photosynthesis to make food for the plants. Without enough light, the Monstera reacts by producing more green leaves instead of the beautifully variegated ones you dream of.
Lack of Holes and Splits
Monstera plants are known for their lacy holes and splits called fenestrations that give them the Swiss cheese appearance. But Monstera need good lighting in order to boost the process. Monstera leaves regularly develop splits and holes as the plant matures. Keeping your plant in low-light conditions may prevent the plant from maturing and producing the dramatic holes and splits you desire.
Low light will discourage growth in your Monstera plant. If indoor plants receive too few hours of light their overall growth rate will decrease. Bear in mind that slow growth for a few months during the winter is normal as this plant needs to rest after a summer of active growth.
If you are like most plant owners you may find yourself asking how much light does a Monstera need. The answer, of course, depends on the actual light conditions in your home. Bright light from a west facing window is more intense than bright light from an eastern facing window. Likewise, light from the same window changes in intensity as the seasons change. The best way to determine how much light Monstera need is to observe them closely for signs of too little or too much light and adjust the amount of direct light they receive accordingly.