Native to Central America, Monstera are a species of tropical vines from the aroid family. Monstera houseplants are known for their gigantic leaves with fenestrations (holes), which is why they are commonly referred to as the “Swiss cheese plant”. There may be a few reasons why your Monstera leaves aren’t splitting, including: inadequate light, young plant age, or improper care. Learn more about why your Monstera leaves don’t have holes, why they develop fenestrations, and what you can do to promote them.
Learn more about general Monstera care with this article.
What are fenestrations?
Fenestrations range from small holes in the the leaf to larger ones extending to the edge and splitting the leaf. As the plant ages, it can grow enormous leaves that feature both holes and slits, making for a gorgeous display of various fenestrations.
Why do Monstera leaves have holes?
There are a few proposed theories about the practical purposes the leaf splits serve.
Wind
One theory is that Monstera create holes in their leaves to resist strong winds. The fenestrations allow the wind to blow through the leaf without knocking the whole plant over.
Water
Monstera are epiphytic plants, meaning they grow upon other plants for physical support. As a result, their roots have little contact with the soil. The fenestrations in their leaves allow water to pass through and provide increased contact with the soil underneath.
Furthermore, Monstera do not like for their leaves to remain very wet for extended periods of time- it can cause rot and promote infection. The holes allow the rain to easily pass through the leaves without sitting on them.
Light
Another theory is that fenestrations develop as a way to increase access to sunlight. As epiphytic plants, Monstera vine up the trees as they grow. They rely on small beams of sunlight that make it through the canopy of trees above. Fenestrated leaves can grow to larger sizes, allowing them to cover a greater area to absorb light. So although a few flecks of light may pass through the holes in the leaves, the overall light absorbed is increased because the area is larger. The splits also allow light to pass through and reach the lower leaves, that would otherwise not receive anything.
Despite these three theories, there is still no singular accepted reason for Monstera fenestration.
Why your Monstera leaves are not splitting
A few reasons why Monstera leaves do not split include: a very young plant, inadequate light, or improper care.
If your plant is still a baby, it may not have any splits yet. Don’t worry- this is normal for young plants and fenestrations develop as the plant ages. Continue to look after the Monstera and provide it with bright, indirect light. If you purchased your plant when it was very young, it may take two to three years before you see fenestrations.
Once your Monstera is old enough to develop fenestrations, it should be provided with bright, indirect light to promote leaf growth. In mature leaves, lack of fenestration is due to: low light, low temperature, low humidity, or nutrient deficiency.
Grow lights are an option if your room does not receive enough light. If you decide to expose your plant to more light, slowly increase its time spent in the sun over a couple of days to help it adjust and avoid burns. Stunted growth and small, thin leaves lacking fenestrations are signs your Monstera is not receiving enough light. They lack the typical glossiness present in healthy leaves.
In addition to light, Monstera should be cared for appropriately to promote growth. A proper watering schedule is very important, as well as fertilizing, and providing the plant with humidity (see below for more information about Monstera care).
Root bound Monstera also tend to produce beautiful, large leaves. Only repot your Monstera once every few years when you notice the growth has stunted, as they prefer for their roots to fill the planter.
Related article: Can Monstera Live Outside
How to encourage holes in your Monstera leaves
Now that we know why Monstera leaves do not split, here are some ways to encourage leaf splitting in mature Monstera plants:
- Provide the Monstera with bright, indirect light– this is the most important factor. Placing your plant near a south, east or west facing window will generally work well. If you find this is not enough, supplement with a grow light. Grow lights emulate the natural light spectrum of the sun and are helpful for areas where natural light is insufficient.
- Prune the older leaves on the bottom- this will encourage new growth and help develop fenestrations. Prune the older, discolored leaves. This allows the plant to allocate its resources to producing new growth.
- Provide your Monstera with its ideal growing conditions– water appropriately when the top few inches of soil are dry, fertilize once a month during the spring and summer, and provide it with enough humidity.
Related article: How to water Monstera
How do Monstera leaves get holes?
The easiest way to promote leaf splitting and holes in you Monstera is to just… let it grow! Monsteras develop holes as they age and grow larger. Their leaf morphology changes as they age- while the plant is young, the leaves lack fenestrations and look similar to other aroid leaves. However, as the plant ages and the plant spans about three feet, it begins to develop fenestrations.
Pruning the older leaves at the base of the plant will encourage the plant to produce larger, fenestrated leaves.
How long do Monstera leaves take to split?
Of course, the easiest solution would be to buy a mature plant, but that is not always possible. If the Monstera you purchased from a nursery already has fenestrations, you can expect future leaves to have fenestrations as well.
If you purchased a young plant, it will typically take two to three years before the leaves begin to split. Younger Monstera have lighter green, heart-shaped leaves. As the plant ages, the leaves grow in size and turn darker. As the leaf grows larger, it shows more details and you should be able to make out if it has fenestrations (however, they are not always visible until the process of unfurling has started).
Once the new leaf has reached the correct size, it will unfurl slowly, exposing the new growth to sunlight. The unfurling process may take weeks to months so do not feel rushed or push it along. Forcing the leaf to unfurl before it is ready causes damage.
As the leaf ages, it will thicken and darken in color.
Can a Monstera leaf grow new holes?
Once the Monstera leaf has unfurled, it will not fenestrate further. Fenestrations are predetermined.
Will all Monstera leaves split?
No, especially on newer plants. Even in older, more mature plants, not every leaf will be fenestrated, which can be a point of frustration for some plant owners. Be sure your plant is receiving enough light.
Monstera growing conditions
Monstera’s ideal growing conditions can be summarized below. Providing your Monstera with the proper environment will promote growth and encourage fenestrations.
| Sunlight | Bright, indirect light. You can also keep the plant outdoors or place a grow light nearby if it is not receiving enough sun. |
| Water | Once every 1 to 2 weeks (check that the top 1 to 2 inches of soil is dry before watering). You may need to adjust the frequency based on the season/sunlight/humidity conditions. |
| Temperature | 68 – 86 °F (20 – 30 °C). Do not keep in temperatures below 60 °F (15 °C). |
| Humidity | High humidity– place a humidifier near the plant to increase humidity. If you do not have a humidifier, you can fill a tray with pebbles and then pour water inside. Then, place the pot on the pebbles (be sure the water is not in direct contact with the pot)- as the water evaporates, it increases the surrounding humidity. Keep the plant away from air conditioning vents or heaters as they dry up the surrounding air. |
| Soil | Pot in a well-draining houseplant potting soil. Add perlite and orchid bark to the soil to create a well-draining soil that reduces the risk of root rot. |
| Repotting | Repot once every two to three years. When repotting, choose a pot about one to two inches larger in diameter than the current pot. |
| Fertilizing | Fertilize once a month during the growing season from April to September with a diluted fertilizer. When it comes to fertilizing, go slow- it is easier to add more fertilizer than it is to remove it if you have added too much. |
For a complete Monstera care guide, check out this article.
In summary for Monstera leaves aren’t splitting…
Fenestrations are theorized to serve multiple purposes, including wind resistance and increased access to sunlight and water.
The most common reason Monstera leaves do not have holes is that they are not old enough. When they are young, the leaves are glossy green and heart shaped, like a Philodendron’s. Once the plant matures, promote fenestration by increasing its light and providing proper care as detailed above.
Have more questions about what to do if your Monstera leaves aren’t splitting? Let me know in the comments below!
