What Are Monstera Fenestrations And What Are They Trying To Tell You?

There's no doubt monsteras have become very popular houseplants. In addition to being easy to grow, and not demanding a lot of attention, their unique beauty can create a statement piece that's hard to miss. They certainly won't be going out of style anytime soon. Those enormous lobed leaves are somewhat reminiscent of an era long gone, when it was the dinosaurs that ruled the planet. One of the most distinctive features of monsteras are the large holes in their leaves. These holes, called fenestrations (from the Latin word for windows), give the plant one of its common names: Swiss cheese plant.

When you look at a monstera leaf, you probably don't think twice about those holes because that's what you expect. But have you ever wondered why they're there, and why some plants have more fenestrations than others? After all, these are totally natural occurrences, and not something a plant breeder has created. There are numerous theories as to why the plant leaves develop these fenestrations. One theory is that the perforations allow more light through to the rest of the plant, but plants grown in a fairly dark environment will not develop these characteristic holes. Another theory states that the holes protect the leaves from damage caused by high winds. 

In 2011, scientists from the Department of Ecology and Evolutionary Biology at the University of Colorado conducted a study on monstera leaves to test the effects of water absorption, wind, and insect damage on leaves with fenestration and those without. The most conclusive results came from the water test. It showed that a greater amount of water was able to reach the roots of the plant itself when the fenestrations were present. This would make sense, considering monsteras are native to South American rainforests, and grow below the canopy of taller trees. If the leaves did not have those holes for water to drip through, raindrops would just slide down the enormous leaves, and end up a long way from the plant's actual root zone. For the wind test, the results showed the solid leaves suffered no more damage than those with holes. Finally, it was found that the fenestrated leaves were significantly favored by insects over those without holes. 

So, from this we can conclude that if your monstera has a lot of fenestrations, it's getting ample light, but may be more vulnerable to insects and pests. If your plant has solid leaves, it's likely in a darker spot, and will require more light if you want to encourage fenestrations. Now that you're armed with this knowledge, you'll also want to know how to prune a monstera plant to optimize its growth.