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I know that 20 sounds like a lot, but a lot of these are pretty easy to fix.
Monstera are a pretty easy-to-care-for plant, but they do have preferences when it comes to how they like to be kept, and if you don’t provide them with the care they need then any problems tend to manifest on their leaves pretty quickly.
But don’t worry, I’ll present you with solutions as well as problems, and feel free to DM me on Instagram if you’re unsure.
Anyway, let’s crack on:
- Yellow leaves
- Brown leaves
- Black leaves
- Fungus spots on leaves
- Brown spots
- Yellow spots
- Leaves are brown before unfurling
- Curling leaves
- Drooping/wilting leaves
- Small leaves
- No fenestrations in leaves
- Black marks on leaves
- Monstera isn’t growing
- Growth is stunted
- Monstera isn’t propagating
- Monstera is leggy
- Thrips and/or other pests
- Monstera is growing sideways
- Aerial roots aren’t growing
- Monstera looks like it’s dying
First things first: your Monstera leaf might just be old.
Monstera leaves can live for a number of years (Monstera themselves can technically grow for decades) but their leaves may only last for about five.
Check where on the plant the yellow leaf is - if it's one of the lower, older leaves it may have just reached the end of its cycle. The main plant will extract any remaining chlorophyll, which is why the leaf yellows.
Waste not, want not!
If multiple leaves are yellowing, then it could be a larger issue.
Yellow leaves on Monsteras are a pretty typical indication that your Monstera is experiencing problems with its roots.
This is usually when there’s too much water in the soil, causing a lack of oxygen to the roots, and commonly happens when we water too often. The lack of oxygen provides the perfect conditions for the bacteria that cause root rot to thrive.
However, there are other ways we can cause overwatering:
- Too big of a pot, so the soil stays wet for too long
- Inadequate drainage
- Too dense soil, so it compacts and there’s no aeration to the roots
- Not enough light, so the plant isn’t growing enough to use the water
- Too cold – the plant is too cold to grow, and the environment is too cold to cause the water in the soil to evaporate.
You can’t generally recover yellow leaves, because the plant has already written them off, but you can recover the roots – I have an article on how to do that here.
Yellow leaves can be a sign of a nutritional deficiency, but be sure to rule out root rot first – a plant with root rot will be further damaged by fertiliser and the roots may not be able to absorb it anyway.
Brown leaves are usually an indication that the plant has been allowed to dry out for too long. A good soak will usually revive the roots but brown leaves are dead and can’t be recovered.
If the leave is completely brown, chop it off.
Brown leaves can also be a sign of sunburn. Monstera can get sunburned very quickly if they’re left in bright light without being properly acclimated.
Sunburn on Monstera can kill the leaves in a couple of hours, but the roots should be ok. Give the plant a good soak and remove any damaged leaves. When new growth emerges, it will usually be better adapted to the bright light.
When you see Monstera in the wild, especially growing outside of their native habitat (which they do a lot as an invasive species) you can often see them growing in exposed areas, and the lower portions are brown and crispy, but the new growth is fine.
This is due to the plant adapting to the light and producing more compounds called carotenoids than give them more UV protection.
Black leaves are usually what follow yellow leaves caused by overwatering.
Typically the black starts at the tip and works its way toward the petiole, but it depends on how rotted the roots are as to how quickly this happens.
If the stem is black then it’s pretty much game over, as you severed the connection between the leaves and roots – chop off the top growth and propagate it. Throw anything brown and mushy in the bin.
Fungus spots on leaves
Fungus spots aren’t necessarily rare when it comes to Monstera, so make sure that when you spots that you think could be fungus you first check that it isn’t root rot.
Fungus typically shows up as rusty spots or small black circles with a yellow outline.
You can buy spray-on fungicides that should do the job.
Brown spots are usually the start of brown leaves, so check for both under and overwatering. Brown spots can also be a sign of thrips:
Brown spots can also be a sign of slight sunburn, but it tends to look blacker – like a ‘real’ burn:
Leaves are brown before unfurling
This can be either under or overwatering (I have an article on how to tell which it is, but generally speaking, if the soil’s wet you’re overwatering, and if the soil’s dry you’re underwatering), but it could also be a humidity issue.
Either your humidity isn’t high enough, which causes the leaf to not form properly, or it’s so high that water has gotten trapped in the rolled-up leaf and caused rot.
This could also be a pest issue, as pests tend to prefer the soft new growth.
Another cause could be that the leaf brushed against something. New foliage is incredibly delicate, and if you touch leaves, however gently, before it’s unfurled and hardened off, you could cause black marks.
I have a whole post here on curling leaves, but the most likely cause is that your Monstera needs water.
Monstera are kept upright with turgor pressure, which is water held in cells under pressure, that keeps the stems and leaves firm.
If the plant is dry, it’ll leach water out of the cells to use in essential functions, and cause the plant leaves to curl.
The curled leaves mean that less of the surface area of the leaf is exposed to the sun, and less water will be lost to transpiration.
Drooping leaves can also be caused by a lack of turgor pressure.
If you have a big, sprawling Monstera you can help get water to the more outlying regions by putting a couple of its aerial roots in water. The increased water can help keep the Monstera from drooping.
Aerial roots can start to function like water roots (and therefore become more efficient) if the water they’re placed in is changed often or well-oxygenised.
Small leaves are usually caused by a lack of light, but can also be a result of low humidity and lack of nutrition.
Monstera are generally pretty tolerant of ambient humidity, so unless you have very dry (lower than 40%) air, then that shouldn’t cause too much of an issue.
Try fertilising your Monstera if you don’t usually (or try repotting it in fresh potting mix), but increasing the amount of light it has will have the biggest impact.
I get a lot of messages asking about keeping plants in dark rooms, but it is rarely a good idea, and will certainly not be conducive to growing big leaves.
If you feel that you have bright light and high humidity, then the issue could be temperature – Monstera are tropical plants and like to be kept warm.
No fenestrations in leaves
This is almost certainly a light issue, but it can be an age thing too.
Monstera won’t produce fenestrated leave until they’re a couple of years old BUT they’ll never produce them if they don’t need them. And they won’t need them if they don’t have enough light.
Growing plants upright can help convince them to grow bigger, fenestrated leaves so perhaps try staking your monstera.
Monstera isn’t growing
There are many reasons why your Monstera isn’t growing:
- Inadequate light
- Not enough water
- Too big of a pot
- Root issues (overwatered/underwatered)
- Too cold
- Needs fertilising
- It has pests
Growth is stunted
Stunted growth is usually caused by a lack of light – have you moved your Monstera recently? Do you need to clean the leaves?
If you have a Monstera with big, fenestrated leaves, it will revert back to producing smaller, solid leaves unless you’re able to match the conditions in which it produced its mature leaves.
Plants don’t grow the way they do for aesthetic reasons – they grow fenestrated leaves to allow light to penetrate to the lower leaves and to be more stable in windy conditions.
If the light is low and there’s no wind it makes more sense for them to produce solid leaves (more surface area for photosynthesis), and they don’t have the energy to produce large leaves.
Monstera isn’t propagating
I have a whole article here on why your Monstera isn’t propagating, but there are a couple of common reasons:
- It’s too cold – you can still propagate in winter if you wish but you’ll need to keep the props warm and it will take longer
- There’s not enough oxygen – if you’re propping in water, you need to change the water every couple of days or add an airstone of oxygenating aquatic plants.
Monstera is leggy
Legginess is a symptom of low light, and it can be a pain in Monstera because it makes them top-heavy and in danger of toppling over.
There are a few ways to keep your Monstera upright, but (I’m a bit of a broken record here, I’m afraid) increasing the light it gets will make it grow faster and will shorter internodal spacing, making it more compact and bushier.
Thrips and/or other pests
Thrips damage can look like black spots like this:
Actual thrips larvae look like this:
Aaand the adults look like this:
Monstera and thrips are best mates and they’re difficult to eradicate.
I like to use a drop of castille soap in warm water, and then spray the plant down liberally twice a week, before wiping the leaves with a cloth (those makeup eraser cloths are so good for cleaning plants btw).
Repeat for as long as it takes (it might be literally months). Thrips lay their eggs IN the leaf, so you never know if more are gonna emerge.
Monstera is growing sideways
I could say that this is a light issue (and it could be!) but Monstera just grow however they want.
You can’t really train Monstera, but you can attach them to moss poles. That doesn’t mean that they’ll grow the way you want though. The stems are very thick and are non-pliable, so moss poles aren’t always viable.
If your Monstera is growing *very* sideways, I’d recommend taking it out of the pot and repotting it so it’s more upright – rather than the stem growing horizontally, it’ll be vertical. The leaves may look a bit odd, but they *might* readjust over time.
If you can, grab some aerial roots and poke them down into the soil. Over time aerial roots can grow into soil roots and help anchor the plant and keep it more upright.
Aerial roots aren’t growing
Aerial roots are really useful on Monstera, because they allow it to attach to moss poles (or the walls/floor of your house) without needing any ties.
However, aerial roots have a specific purpose and the plant won’t waste energy producing something it won’t use.
Not having aerial roots isn’t a problem in itself – if the plant needed them, it would grow them.
If you want the plant to grow aerial roots, you need to provide it with enough light, water and warmth to make it worth its while. To grow aerial roots that will grab onto, e.g. a moss pole, you’ll need high humidity.
Monstera CAN attach to those dry coir poles BUT the humidity needs to be really high. Coir poles are certainly not ideal because they’re too dry for the Monstera to grow towards. I prefer these plastic moss poles that you fill with spaghnum. They’re stackable but quite thin, so you may need a couple for a large plant.
First of all, get a second opinion – a forum like Reddit should do – because Mosaic virus can look like thrips damage or nutrient deficiencies.
If it does have it, I’m pretty sure you have to burn it. Sorry.
Water dripping out of Monstera leaf
Water droplets on the end of Monstera leaves is a natural part of a process called guttation, which occurs when the plant takes up too much water and has to excrete it out of the leaves.
If this is happening a lot then keep an eye on your Monstera’s coil because it CAN indicate overwatering, but also Monstera are renowned for being greedy with water and guttating a lot. I have a whole article on guttation here.
I know, I know, a lot of talk about underwatering, overwatering, and giving Monstera more light.
Honestly, a tonne of light is the key to a healthy Monstera. They grow bigger, faster, and are less susceptible to pests. It’s just a shame they’re too big to put under grow lights without dedicating an entire light set up to them.