Yes, Monstera need drainage.
But what does that mean?
Drainage is one of those words that gets thrown about with wild abandon when we’re talking about house plants, but it’s rarely actually explained.
I mean, what actually is good drainage? And why is it important? And, most importantly, how will I know when I have good drainage?
Drainage isn’t often discussed when we discuss repotting Monstera, because we’re too busy talking about how much light they need, how to get them to grow fenestrations, and what the heck to do with all those creepy aerial roots.
But drainage is important to get right in house plants because getting it right can prevent problems further along the line – things like overwatering and yellow leaves can be avoided if we have the right drainage.
I have a complete guide to Monstera deliciosa here.
Why is drainage so important for Monstera?
Having adequate drainage is especially important for Monstera because of the way they grow.
Monstera are secondary hemiepiphytes, so they grow in the ground, then start to climb trees and can eventually break contact with the ground (primary hemiepiphytes germinate in the canopy and send roots down to root in the ground).
It wouldn’t be very practical to grow Monstera as epiphytes (unless you have a massive tree in your living room), but it’s important to remember that Monstera roots grow best when they have a lot of oxygen around the roots – because that’s what they’ve evolved to do.
We can increase that oxygen by making sure they have good drainage.
If we don’t give them enough oxygen around their roots, that can lead to root rot.
Now, Monstera deliciosa aren’t typically that susceptible to root rot, for a variety of reasons:
- they have very thick roots that grow quickly
- Monstera have been popular house plants since the 1800s and they’ve been selectively bred to be easy to care for
and also
- they’re pretty easy to reroot if they do get overwatered.
However, some Monstera deliciosa varieties are pretty susceptible to root rot, especially the Thai Constellation. I keep mine hydroponically with a lot of oxygenating plants in the water because it kept getting root rot in soil.
Monstera Thai constellations were created in a lab, so something in the process, or even just the genetics of the plant that was used, have meant that Thais are a little more prone to root rot than regular greens.
As far as I’m aware, Albo don’t have the same issue.
How to ensure your Monstera has good drainage
But how do we make sure that our Monstera soil is well draining? Don’t worry, there’s a pretty easy three-step process that will ensure your Monstera is well drained:
- Well-draining soil
- Don’t let your Monstera sit in water
- Don’t let your soil get compacted
Well-draining soil
I know, I know. Don’t worry, I’ll explain what that means and how to get it.
How to tell if your soil is well draining
Well-draining soil is soil that allows water to soak into it and move through it easily. It shouldn’t pool on the top, or collect in pockets in the soil.
The soil can retain some water, but not so much that it all clumps together into what is essentially expensive mud.
How to make soil better draining
If you find that your soil isn’t well-draining then there are things to add to make it chunkier and allow water to drain better.
- Orchid bark
Orchid bark is made up of quite large pieces, so physically breaks up the soil and allows air pockets to form, and lets water move through quickly.
It can retain some water, but not a lot. It breaks down over time, but as it does so will release nutrients into the soil
- Perlite
I have an article on perlite here, but long story short, it’s a volcanic rock full of holes that can break up the soil and allow water to move through it quicker, but it can also retain some water, and release it as the soil dries out
- Sand
Sand can be added to soil to make it very well-draining, but is best added to plants that don’t like to sit in moist soil, like succulents. It can be added to Monstera soil if you feel it retains too much water, but orchid bark or perlite (or a mix of both) are better options.
How much you add depends on how dense your soil is. If you’ve no idea where to start, take the plant out of the pot and remove as much soil as you can.
Remove a quarter of the soil and replace with orchid bark or perlite or a mix of both. Mix in with the soil and re-pot your plant.
See how your plant does. If it seems happier (grows more, not droopy), keep it as it is.
If the soil is staying wet for too long (more than three weeks), add more perlite/bark.
If it’s drying out too quickly, remove some soil mix and add some of the soil you removed initially back in (which you remembered to keep).
Can soil be too well draining?
Absolutely.
There’s no such thing as the perfect soil for Monstera, bar planting it in a rainforest in Mexico.
Instead, you need to work out what kind of a plant person you are, and pot your Monstera accordingly – remember: they’re pretty chill plants.
If you’re an overwaterer, you want your soil to be very chunky and well-draining, so the soil dries out quickly.
If you’re an underwaterer, you want your soil to be denser and retain more water. There’s a limit to this, but I usually recommend that underwaterers stick to regular store-bought house plant potting mix – you can always add in soil amendments later if you wish.
Chunkier soil is technically better, but if you’re just going to let it dry out to dust, then go with something denser.
How to make soil retain more water
There are a couple of ways to help your soil retain more water:
- Perlite
Yes it helps soil be more free draining, but it also retains water too – it’s really the MVP in house plant care
- Coco coir
Coir is made from coconut husks and can hold a lot of water
- Spaghnum moss
Again, this can hold a lot of water. Try to buy it sustainably if you can.
The problem with both coir and sphagnum is that they can become quite hydrophobic over time, so if they get too dry it can be difficult to get to them absorb water. An easy solution is to bottom water them or soak the whole root ball in a bucket of water to rehydrate.
Don’t let your Monstera sit in water
I know I just suggested bottom watering, but the difference between letting your Monstera sit in water and bottom watering is that you only bottom water plants when they're dry, and then once the soil is evenly moist you remove any remaining water.
So, how do we ensure our Monstera isn’t sitting in water?
Ensure there are holes in the bottom of the pot
This warrants its own article.
The excess water needs to be able to drain away, and the only way that can happen is if there are holes it can exit through.
Make sure they’re in the base, not just low down
A new trend I’ve seen in pots is to have the drainage holes be in the sides of the pot, not the bottom, a couple of centimetres/an inch up.
This is no good. The holes need to be in the bottom because any water that pools in the bottom will ensure that the soil doesn’t get a chance to dry out properly – and that’s how we get root rot.
What if the pot doesn’t have drainage holes?
If your Monstera pot doesn’t have holes in the bottom, you have a few options:
Use a plastic pot as a cachepot
Take the Monstera out of the hole-less pot and put it in a plastic one that will sit inside.
You can either
a) take the plastic pot out of the ‘proper’ pot and water it thoroughly before returning it
or
b) water in situ, and dump and remaining water out later.
I actually like option b), because a small amount of time sitting in water (say, half an hour) can allow the soil to absorb a bit more water.
It’s like combining top and bottom watering, but make sure you remember to empty the outer pot.
Drill holes
Fairly self-explanatory. This video explains it well.
Don’t add gravel as an alternative to drainage holes – it isn’t one
I have a whole post on this. Adding gravel to the bottom of hole-less plant pots doesn’t add drainage, it just creates a perched water table.
Let me crack out my amazing diagram again:
As well as creating a perched water table, the level of the water that will collect in the bottom will get higher every time you water, and over time will reach the soil line and you’ll end up with a rotten, muddy mess.
Don’t do it guys.
You COULD put leca in the bottom, but I wouldn’t advise beginners to do this. It’s a technique for experienced plant people that tend to underwater. And I’d still recommend having holes in the pot.
By the way, if your pot is way too big for the plant you could add gravel to the bottom to reduce the amount of soil (and therefore the amount of water being held in the soil) BUT you need to make sure that there are drainage holes.
Keep soil from getting compacted
Compacted soil leaves no room for air pockets and therefore oxygen.
(If you’re wondering how you can keep plants in water/hydroponically, yet waterlogged soil causes root rot, then read this article, but it’s broadly the same reason why fish die in stagnant water)
So, how do we go about stopping soil from getting compacted?
Repot when necessary
Soil becomes more liable to compact as it gets older and breaks down into smaller and smaller pieces. If you’ve had a plant in the same soil for a few years, consider changing the soil, even if the plant isn’t rootbound.
If the plant is healthy, a full soil change shouldn’t harm it, though it may seem a little shocked for a week or two. If the soil seems unhealthy, then only replace about half the soil (unless you think the soil is what’s causing it to be unhealthy).
Manually fluff up the soil
You can use a chopstick, or the probe of a moisture metre to manually stir up the soil and stop it from being compacted. Be aware of the roots, but if the plant has a healthy root system a few punctures won’t adversely affect it.
Is decompact a word? Uncompact? Grammarly doesn’t like either, but I quite like decompact.
Be gentle when you top water
If you top water quickly – for example, you use something without a spout (like a jar) or just water so aggressively to get splashback, then you could inadvertently be compacting the soil – you’ve essentially created a waterfall and the resultant plunge pool with the soil beneath compacting over time.
You don’t have to stop watering like this, just be aware of it, and every few months bottom water, and use a chopstick to rearrange the soil and fluff up the compacted soil.
Try bottom watering
I’ve already mentioned this, but it works and can be convenient if you have the space to keep a large tray of water out. When plants are dry, rather than getting out your watering can, pop them in the tray of water for half an hour or so (depending on the size of the plant.
You can add nutrients every few weeks to fertilise.
Be aware of hydrophobic soil
Soil (or certain components of soil, like coir) can become hydrophobic if they’re left to dry out for too long. The soil won’t absorb water easily, and the only way to get it to do so again is to soak it for a minimum of about fifteen minutes.
Final thoughts
Good drainage is important for Monstera, but you also need to consider the care you give – if you’re an underwaterer then a less free-draining soil might be better for you – within reason, of course, you can’t keep Monstera in too dense a mix.
If you really struggle with keeping up with watering your plants, then keeping plants hydroponically with oxygenating plants in the water might be a good option for you.
If you have any queries, don’t hesitate to leave me a comment – I try to reply within a week. If that’s too long, DM me on Instagram.
