Feeling Split - The World of Split Leafed Plants

Many of us have heard the name "Swiss Cheese Plant" and I bet we each envision a completely different plant from one another. These plants all have something in common: lush foliage with perforations throughout their leaves which appear without having been physically damaged. We use this common name to describe plants with leaves which have holes, or perforations called leaf fenestration's but in reality there are a number of plants who fit this description. In this blog post we are going to explore this unique and visually stunning group of plants who share this moniker.

What are fenestration's and why are they there?

There are a variety of plants who develop holes in their leaves and there are just as many theories about why these plants grow in such a way. As many of the plants (like the Monstera deliciosa) who develop fenestrations are hemiepiphytes meaning they spend part of their life cycle as epiphytes, climbing up woody trees with aerial roots which extract nutrients through the atmosphere.

It is thought that the holes allow for greater penetration of the suns rays and water to the plants lower leaves and aerial roots closer to the forest floor. Another theory is that these fenestrations help plants withstand heavy winds and rains by reducing their surface area, therefore lessening their chance of sustaining heavy damage during inclement weather.

Some plants develop their splits as they age, meaning their leaves are solid when they unfurl and then develop their slits and holes as they age, others have holes in their juvenile form. This can vary from plant to plant, so we will discuss the ins and outs of some specific plants who have these characteristic holes next.

Monstera deliciosa

Monstera deliciosa aka Swiss Cheese Plant aka Split Leaf Philodendron is a plant which has gained huge popularity in the past couple of years. This plant with its dinner plate sized leaves is a hugely popular houseplant at the moment after falling into obscurity for the past 30 years after being extremely popular in the 70's. But like many things, what is old is new again, and M. decliciosa is no exception.

M. deliciosa are normally sold in garden centres like ours in a somewhat compact form, which is deceiving as they don't stay compact for long.

Monstera deliciosa

Minor aerial root developing

These hemiepiphytes in their natural habitats (native to Central American) begin their lives growing on the forest floor, then find a woody tree and begin to climb up the trunk with its aerial roots. These aerial roots eventually take over for the ground roots in nutrient and water acquisition. M. deliciosa have been known to completely detach from their ground roots only to reroot a while later. These plants are truly wild in their growth pattern and manners. When not supported by a tree or trellis as such in a home, they can become quite wide and ungainly. So if you are planning on adding one to your space, be sure that you allocate it a wide spot.

A variety of different M. deliciosa leaves in stages of growth. Note some of the least perforated leaves are the oldest, while some of the most are brand new. This highlights that these plants follow very few patterns in their fenestration development.

Give your Monstera deliciosa space to grow.

Their fenestrations develop as the plant ages, with some of their juvenile leaves bearing no holes, and then later developing them as the leaf ages. Some juvenile leaves unfurl with holes already throughout. Leaves may have splits or holes or a combination of the two. So as much as you read online with one explanation or another, the general rule is that M. deliciosa leaves will develop fenestrations as they age. But, in my personal experience, these plants will grow either way and sometimes all on a single plant!

Monstera adansonii

Commonly known as Swiss Cheese Vines, Monstera adansonii are a smaller vining cousin of the Monstera deliciosa. We often bring these popular plants in hanging baskets and in 4" pots for our customers. Their leaves are more long and narrow than they are wide. Much like their larger cousin the M. deliciosa, they grow their shape and fenestrations in a variety of manners. Typically the juvenile leaves have less fenestrations, are thinner and more delicate than the mature leaves. Typically, M. adansonii fenestrations are primarily holes and rarely breach the edge of the leaf to create a split.

Monstera Adansonii hanging basket
Juvenile leaves with minor fenestrations.
Mature adult leaf with numerous fenestrations.

Being plants from tropical forests, these plants (both Monstera deliciosa and adansonii) do not tolerate a large amount of hot, direct sunlight. A bright but filtered light location is best. Additionally, these plants are used to competing for water and nutrients in their native forests and therefore like the top two inches of their soil to dry out between waterings. Fertilize with a all purpose tropical plant fertilizer like Schultz Liquid Plant Food 10-15-10 throughout the growing season and cease during the winter (from about October to March). Also, keep in mind these plants grow in humid tropical regions so misting and warm room conditions are best.

To enjoy their unique leaves, support their stems or vines with stakes or a trellis system which will encourage them to grow taller.

Rhaphidophora tetrasperma