One of the defining features of a Monstera plant is the large holes that form in their broad, glossy leaves. These holes give the Monstera the name ‘Swiss Cheese Plant’ and are a way the plant has adapted to survive in its native tropical environment. In this guide we will take you through why Monstera leaves have holes, what they do and when they appear.

Why do Monstera leaves have holes?

The holes in a Monstera leaf are called leaf fenestrations and are a method that tropical houseplants use to survive in their natural habitat. These holes form for a few different reason, the main ones being:

Allowing the plant to receive more sunlight - the Monstera naturally grows in tropical forests, under the canopy of taller plants. This means that it needs to maximise its opportunities to collect sunlight. The holes will increase the surface area of the leaf, which gives it more opportunity to absorb sunlight and create more energy for itself.

Letting the Monstera absorb more water - Monstera and other tropical plants absorb water through their foliage as well as their leaves. In some varieties, the plant will take in most of the water it needs through the leaves and the roots are just there for stability. The holes in the leaves help ambient moisture to condensate on the leaves and helps redirect rainwater down to the roots.

Protecting against strong winds - a lot of Monstera species make tall houseplants and in the wild they are known to grow up to 12 feet in height. When a plant grows this tall it is susceptible to strong winds that can uproot the plant. The broad leaves of some plants can act like sails in strong winds that help to pull a plant over or can rip off and damage it. The holes allow the wind to pass through and keeps the plant secure and in place.

When will my Monstera leaves split?

Monstera leaves won’t start with fenestrations in them. When you first get your plant the leaves will be a uniform and unbroken heart shape, but the leaves will develop as the plant grows. Given the correct growing conditions you can expect the leaves to split when the plant is between two and three years old. However, sometimes the leaves of your plant just won’t split. If this happens, don’t worry, there are plenty of things you can do to help the leaves split.

What to do if a Monsteras leaves won’t split?

Sometimes your Monstera will be stubborn and the leaves won’t split for a lot longer than usual. If you find that happening there are a few things you can do to help it along.

Step 1 - Wait a little bit

If you have recently got your Monstera and it is still young, you will need to wait for your plant to mature before the leaves split. Leaf fenestrations typically appear once a Monstera is two to three years old.

Step 2 - Add more light

In almost all cases, the reason your Monstera leaves aren’t splitting is because your plant is not getting enough light. Leaf fenestrations take some energy to develop and your plant will need enough light to develop them.

Because leaf fenestrations are a natural adaptation to sunlight you need to supply enough light for the plant to react to. There are a few steps you can take to increase the amount of light your plant gets. First, move your plant to a sunnier location but remember that the light needs to be bright, but indirect. If you are unable to increase the light by moving the plant consider adding some grow lights around your pot to mimic a sunnier location.

Step 3 - Make sure you are watering and fertilising enough

Sunlight is by far the most important factor to prompting your Monstera leaves to split, but watering and fertilisation can have some effect too. If your plant is dehydrated or malnourished then it won’t have the energy to develop fenestrations since it will be in a more dormant state.

Double check that your plant's soil is well-draining and not too wet, and make sure you are fertilising the plant regularly during the spring and summer.

In summary, the key to helping your Monstera leaves split is to recreate its natural environment as much as possible. For a tropical house plant like a Monstera this means having the plant in a warm environment with bright, but indirect light. Make sure the air around your plant is humid and that it is regularly fed in the spring and summer.