When & Why Do Monstera Leaves Split?

Not sure why your Monstera leaves or splitting, or perhaps why they aren't? Maybe you are unsure when it should happen? In this article, gardening expert and houseplant enthusiast Madison Moulton takes you through everything you need to know about splitting leaves with your Monstera plant.

Written by Madison Moulton Last updated: October 4, 2023 | 5 min read

Split Monstera Leaves in Houseplant Container

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Monstera is a genus of tropical plant native to Central and parts of South America. Appreciating warm and humid conditions, they have become one of the most popular houseplants for indoor gardens, but can also be planted outdoors in tropical and semi-tropical zones. The large leaves of the most well-known species, Monstera deliciousa, are instantly recognizable around the world.

Often used in interior design to create a feeling of tropical paradise, Monsteras are likely the most famous of all indoor plants. This fame is for many reasons, from ease of care to impressive size. But ask any houseplant lover what sets Monsteras apart from the rest of their collection and they will say the holes in their leaves.

Scientifically known as fenestration, this fascinating phenomenon has been pondered for decades. Entire holes in the foliage (that aren’t the result of damage), as well as splits in the sides of the leaves, are the one characteristic every Monstera owner looks forward to.

However, fenestration is not always guaranteed as some may assume. Problems with growth or even age can impact splitting, causing emerging leaves to remain a solid green. While these leaves still look great, they do often indicate a growing concern that should be resolved to keep your plant healthy. In other words, a holey Monstera is a happy Monstera.

Why Do Monstera Leaves Split?

Houseplant with Split Leaves Growing in White Terra Cotta Container. There is another smaller plant near by, and both plants are sitting on a small brick pathway. — There a scientific theory as to why their leave split.

In the botany world, fenestration was somewhat of a mystery for many years. In some ways, it still is, as there is no confirmed explanation for why these plants developed gaps in their leaves, especially since other plants in similar environments haven’t.

Some studies have put forward a theory linking these splits and holes to sunlight levels. Growing up trees and under the shade of tall canopies in their native habitats, the large leaves of most Monstera species need all the light they can get to grow successfully.

The theory is that they evolved to develop gaps and splits to increase the surface area without having to expend energy producing more leaf tissue. This increase in surface area allows the leaves to capture more flecks of sunlight for photosynthesis, improving growth.

There are a few other suggestions that, while not scientifically tested, certainly sound plausible. Some argue holes developed in the large leaves to allow sunlight to pass through to the leaves lower down, maintaining leaf size in all parts of the plant.

Others believe the holes help the stems resist damage from high winds and prevent water from collecting in the foliage and causing rotting.

Whatever the cause, we know that this fenestration is a sign of a healthy Monstera in conditions close to its native habitat. Replicating this environment is key to getting the leaves to split.

When Do Monstera Leaves Split?

Green Plant with many divided leaves and holes. The image is a closeup of the many different fenestrations in the leaves of the plant. — Age is the biggest factor in determining when leaves start to split.

Age is the most important determinant of splitting. Monsteras will only develop holes in their leaves when they are at least a year old, usually closer to two or three. Before that time, the leaves will appear small and solid, slowly increasing in size over time as the plant grows.

After three years, new leaves that emerge should develop splits in the right conditions. As the leaves grow larger, they may develop additional holes toward the center too. However, this doesn’t often happen indoors unless your Monstera is very large and has plenty of space to grow and develop.

If the leaves of your Monstera remain solid after several years of growth, you may have a problem with the environmental conditions around your plant. Resolving these issues should fix the problem and have new leaves splitting in no time.

Reasons Your Monstera Leaves May Not Be Splitting

There are a few different factors to consider when evaluating why your Monstera may have leaves that haven’t split yet. Let’s take a look at some of the most common issues, and how to remedy them.

Age

Young Monstera Plant with No holes in Leaves. The plant sits in a small white pot on a light wooden desk in a darker room. — As mentioned, age plays a part in when leaves start to split.

The first factor to consider is age. If your Monstera is still young, all the leaves will appear solid without holes. Patience is all you need as once the leaves grow a bit larger and the plant matures, splits should begin to appear.

If your Monstera still doesn’t have any splits after three years, look for other potential causes related to their growing conditions.

Lack of Sunlight

Plant with Some Leaves Not Splitting on Monstera. The plant is younger and you can see one of the single leaves is more solid than the others that have started to split. It sits in a white ceramic pot on a chair, in an office setting. The room is also dark, not letting in a lot of light. — Without enough light, leaf fenestration will take place at a slower pace.

Given the posited theories for the reasons behind fenestration, it’s understandable that a lack of sunlight will impact these plants.

Monsteras require bright indirect light for a full day to grow their best. Some can handle moderate to bright light, but low light is certainly not suitable if splits are what you’re after. Low light leads to less photosynthesis and much slower growth. This slow growth keeps the leaves small and stops them from developing splits.

You can see this in action when you forget to rotate your pots. One side of the plant closest to the light source may develop splits while the other leaves emerge solid. In some cases, a single leaf will develop splits on one side and not on the other.

Improving the light levels should encourage leaves to grow more and develop splits, especially in new emerging leaves. Give them bright indirect light, or even an hour of gentle early morning sun, to resolve the problem.

Underwatering

Dying and Underwatered Houseplant being held by gardener. The leaves are yellow, brown and wilted due to the lack of moisture in the plant. — Underwatering can contribute to a lack of fenestration, as well as other plant problems.

Sunlight is only one component of photosynthesis. Another important factor in the process is water. Monsteras are moisture lovers and need consistently moist but well-drained soil to be at their best.

Underwatered Monsteras will grow slowly and may stop growing at all, halting any potential splitting in the leaves. You may notice the leaves turn yellow, brown, or die off entirely.

Avoid underwatering by checking the moisture levels in the soil regularly. Water again when the top layer of soil has dried out, depending on the size of the pot your Monstera is planted in. Make sure there is plenty of drainage in the pot and the soil to prevent root rot.

Lack of Nutrients

Gardener treating young plant with proper fertilizer mixture. On the table is a plant sitting in a reddish plastic pot, with a terra cotta pot next to it and some water in a green plastic water bottle for spraying leaves. — Without the right nutrient balance, Monstera leaves will not fenestrate.

Just as humans require nutrients to sustain themselves, so do plants. A wide range of nutrients, from macro to micro, serve specific functions and work together as a whole to aid in plant growth and health.

When growing in containers, these nutrients are used up by quick-growing plants, requiring a top-up in the form of fertilizer to maintain growth. Without a regular fertilizing routine, your Monstera’s growth may slow dramatically, halting any potential splitting in the leaves.

Feed your Monstera around once per month, depending on the performance and size of the plant. A balanced fertilizer will provide everything they require for strong growth. Avoid overfertilizing by reading the instructions and diluting your chosen product to half-strength.

No Pot Space

A houseplant sits in a crowded pot in the corner of a house. The plant has no room to grow in the pot and is limited in size. — A root bound plant will have problems with growth, including leaf fenestration.

In the right environments, Monsteras can grow incredibly quickly, filling out the available space in their pots in no time. Once roots start curling around each other and sneaking through the drainage holes, it’s time to repot. If you don’t give your plant this additional space to develop, it will stop growing and putting out new leaves, also potentially impacting splitting.

Repot your Monstera into a pot around two sizes up. Use a light houseplant potting mix to improve drainage and limit risks of root rot. There may be some signs of struggle for the first few weeks while the plant adapts, but growth should return to normal after this adjustment period.

Final Thoughts

Monsteras are essential plants to have in any collection, especially when their leaves are beautifully split with that symmetrical look we love. It will take a couple of years to develop these splits, but with consistency in care and a good environment, you’ll get to enjoy this gorgeous look for years to come.