Decoding the Fenestrations: Why Does My Monstera Have Holes?

The Monstera deliciosa is famously known as the "Swiss Cheese Plant," and for good reason!¹ Its large, lush leaves, pierced with numerous natural holes and splits, are instantly recognizable. These holes are not the result of a pest or damage; they are a complex, evolutionary feature known as fenestrations.

Photo by Stanislav Kondratiev: https://www.pexels.com/photo/big-verdant-leaf-of-monstera-in-bright-room-4842544/

If you've ever wondered why your plant has them, or why your newest leaf doesn't, this guide will decode the fascinating science behind the Monstera's iconic look.

🔎 What Exactly Are Fenestrations?

Fenestration is the botanical term for the splits and holes that naturally develop in the leaf blade of the Monstera.² The leaves start out solid, and as the plant matures, three distinct types of leaf structures appear:

1. Juvenile Leaves: Small, heart-shaped, and completely solid (no holes or splits).

2. Transitional Leaves: Larger, showing inner holes (perforations) but sometimes few or no outer splits.

3. Mature Leaves: Very large leaves with both inner holes and deep splits that extend all the way to the edge of the leaf.

🌿 The Science: Why the Holes Exist

Botanists and plant scientists have several compelling theories about why the Monstera—which evolved as a climber in the dense, dark rainforests of Central America—developed this unique feature:

1. Rain and Wind Resistance (The "Hydrodynamic" Theory)

This is the most popular theory. In the rainforest, heavy downpours are common. If the leaves were solid, the rainwater would pool, weigh the leaf down, and tear it.

• The holes allow heavy rain and wind to pass directly through the leaf without causing damage.³ This is essential for a plant that may grow many stories high into the canopy.

2. Capturing Scattered Light (The "Light Maximization" Theory)

Monstera plants live underneath a thick, multi-layered canopy. They need to be incredibly efficient at capturing light.

• By creating holes, the plant ensures that the leaf surface is not a solid shade barrier. Light that makes it through the upper canopy can pass through the holes and reach the lower leaves of the same plant.⁴ This maximizes the plant's overall efficiency in low-light conditions.

3. Energy Efficiency

Producing a large leaf takes a lot of energy. By building a leaf with holes, the Monstera can create a larger functional leaf surface using less energy and biomass than if it had to fill in all that space.

✅ How to Encourage Fenestrations

The number one question plant owners ask is: "How do I make the holes appear?" The key is simple: maturity and mimicry. You must replicate the plant's ideal jungle conditions.

Factor	What Your Monstera Needs	Why It Works
Light	Plenty of bright, indirect light.	Light is the strongest catalyst. When the plant gets enough energy, it signals that it has the resources to build complex, fenestrated leaves.
Support	A moss pole or trellis.	In the wild, the plant is vertical. Providing vertical support allows the plant to perceive itself as "climbing" and mature faster.
Water & Food	Consistent watering and regular feeding.	A well-fed, well-watered plant has the energy reserves needed to produce the largest, most complex leaves.
Age	Patience!	The plant must reach a certain biological maturity (usually when it has at least 8-10 solid leaves) before it starts producing split leaves.

If your Monstera is still producing solid leaves, don't worry—it just means it's still in its juvenile stage or needs a slight upgrade in light! Give it time and brightness, and the holes will come.