When do Monstera Leaves start to split?

I know I’ve been a bit heavy on the Monstera content recently, but it’s for a few reasons:

1. They’re awesome plants for beginners
2. People like Monstera content
3. I want a big-ass Monstera with leaves the size of dinner plates

What do we mean by splits?

There are a tonne different words that people use to decribe Monstera fenestrations. I like fenestrations because it’s a cool word and refers to both the splits and the holes.

They’re the bits in the leaves that aren’t there, as it were. Luckily my little content break is of a Monstera leaf. Look at it. The splits are where the leaves split. The holes are the holes in the leaf. Both are fenestrations. We all clear?

If you have a baby Monstera, yours may not have any splits yet. Don’t worry – if you look after it even moderately well, and don’t keep it in low light, you’ll be blessed with fenestrations at, er, some point.

Why do Monstera leaves split?

There are debates by scientists about why these leaves exist. It’s generally thought that Monstera have splits to regulate light, but I think all three explanations are equally valid, and all fall under the same general reason:

Monsteras have splits in their leaves to help the plant grow bigger and stronger more quickly.

Reason #1 that Monstera have splits: light

The general consensus at the moment is that Monstera have splits in their leaves to allow light to travel through the leaves and reach the lower leaves.

Monstera grow larger leaves as they grow towards the light, because they have to get more energy to support their increasing size.

But a big leaf will shade the leaves below, reducing the overall light that can be absorbed. So the splits and holes allow the light to penetrate.

This makes sense – Monstera adansonii tends to be bushier and have shorter petioles than Monstera deliciosa, so they have more pronounced holes from the beginning.

Reason #2 that Monstera have splits: water

Plants don’t like getting wet leaves. At the very least it blocks their stomata, and at worst, it can cause them to rot and allow fungal and bacterial infections to gain a foothold.

Plants do like getting wet nodes and roots. It allows them to absorb water and nutrients and grow quickly.

Thus having fenestrated leaves kills two birds with one stone – it allows rain to easily get through the leaves without sitting on them, and the rain can easily reach the ground, where the roots can absorb the water.

Wow. Never thought I’d be the kind of girl that said things like ‘thus’.

Reason #3 that Monstera have splits: wind

Since Monstera don’t typically live in exposed areas (though they’ll give any conditions a go) this seems less likely, to be the reason that Monstera evolved to have fenestrated leaves, but it’s worth talking about.

It’s probably one of the reasons that Monstera Deliciosa is considered an invasive species.

The holes allow wind to pass through the leave without knocking the plant over. Makes sense, doesn’t it?

Incidentally, it’s thought that the reason that Bird of Paradise plants have split leaves is to deal with wind. They typically live in more exposed areas than Monstera, where light is easy to come by.

But since Monstera are so adaptable, having holey leaves has probably allowed them to grow in exposed areas that they’re not *technically* designed.

Whether they’re meant to be or not, I think that fenestrated leaves are multi-purpose.

What causes Monstera leaves to split?

There are three main factors to consider here: age, light, and general care.

Age

Nothing you can do short of getting a degree in botany can get your Monstera split before it’s of age.

(Botanists, feel free to share any secret Monstera splitting techniques in the comments)

If you’re on a budget and patient, you can pick up a super cheap baby Monstera, but you may have to wait a couple of years until it’s ready to produce even one split.

I have a young Monstera in an east-facing window. No holes yet, but he has split leaves down to a t. It took a few practice tried of producing splits on only half of the leaf, but he got there in the end.

So much about plant care is about patience. Your monstera will produce splits when he’s good and ready, regardless of how well you take care of him.

Remember that those MASSIVE monstera that go viral on Pinterest are likely to be a few decades old. You can’t rush nature (again botanists, give us tips to rush nature).

Light

Once your Monstera is old enough to start producing split leaves, you’re going need to put him in bright, indirect light if you want those super big leaves.

For those of us that are incredibly impatient, bright, indirect light may not do the job, so you may want to put him in bright light.

You’ll need to do this slowly over time. Don’t leave your Monstera in bright light during the hottest part of the day unless it’s well-acclimated.

I would recommend putting it out in the soft morning light first, and then bringing it back in. Then gradually increase the amount of light over time.

If you live somewhere with hot sun, keep it somewhere shady.

Grow lights are an option if you can’t put your plant outside, but I’m not sure if the leaves will grow as big as they would outside. I suppose if you got really strong ones they might but you run the risk of burning the leaves.

General care

Your Monstera will never grow big beautiful leaves without being old enough, or without enough light, however well you care for it.

Without adequate light, it’ll be a waste of energy for your plant to grow big leaves. If you buy a Monstera with already split leaves but don’t provide it with equal amounts of light, the leaves will revert to their juvenile shape and size.

But here’s the thing, more light = more care. You’ll need to water your Monstera more often, and keep humidity in check.

Don’t let your Monstera get super root bound, but don’t let it drown in its pot. You’ll need to fertilise every six weeks or so, and make sure it has a great quality potting mix.

I have an article here about encouraging your Monstera to grow as quickly as it can.

How to encourage split leaves on a Monstera

• Give it more light

Either move it nearer to the window, move it outdoors, or invest in a grow light.

• Prune the smaller bottom leaves

I read about this tip here, and I have no idea if it works, or why it would. I’m undecided whether I want to give it a go or not.

• Take great care of it

Don’t miss any waterings, don’t over water, fertilise enough (but not too much) and keep up your humidity. Good luck.

Why is my Monstera not splitting?

• It’s not getting enough light

• It’s not old enough

• It doesn’t have the energy/resources

Read this post on providing the best conditions for your Monstera. Whilst it’s pretty difficult to kill a Monstera, they also require specific conditions if you want them to grow super quickly.

Final thoughts on encouraging your Monstera to produce fenestrations

If you have your heart set on getting a mahoosive Monstera will beautifully fenestrated leaves, then your best bet is to buy one.

Unfortunately I, like most of us, don’t have a couple of hundred quid to drop on a plant, so feel free to join me in the waiting game.

I have pretty much decided that my Monstera will be going outside this year, although I think I’ll bring it in most nights. If nothing else, it’ll give all the predatory bugs in my garden a nice thrips feast.