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Monstera deliciosa care is pretty straightforward, and feeding them is no different.
A general house plant fertiliser, watered into the soil every six weeks will be fine.
The secret formula to growing huge Monstera doesn’t really depend much on a great fertilising schedule. If you want big, fenestrated leaves, then you need a lot of light and humidity.
Fertilising will definitely help your plant along on its journey to Monstera monstrousness, but whilst great light can overcome a bad feeding regime, great feeding means nothing without enough light.
How do you know when to fertilise Monsteras?
Monstera adansonii tell you clearly when they need feeding – they go all mottled (in a very ‘oh no, is that mosaic virus’-type way):
Annoyingly, not many plants tell you as plainly that they need fertilising.
In fact, if a plant looks sad or just like it’s lacking something, it’s rarely hungry. House plant potting mixes are pretty good nowadays and will keep your plant fed well enough.
I don’t look for signs that my plant is hungry. There aren’t any that are a definite ‘I AM HUNGRY, HUMAN. FEED ME’
If your plant is showing, for example, yellow leaves, fertilising it will only help it if it is hungry. If the yellowing is caused by anything else, you’re more likely to be hindering it, rather than helping.
Fertilise on a schedule. Honestly, it’s the easiest way. House plants only have about four different symptoms of something being amiss, and there are dozens of issues.
How often should I fertilise my Monstera?
As a general rule, you shouldn’t have to fertilise your Monstera for about a year after you’ve bought it, because nurseries use potting mixes that contain slow-release fertilisers.
HOWEVER
If your Monstera is given a load of light and humidity, and it grows super quickly, then you may as well fertilise it from the get-go.
Monstera roots grow very big and very quickly – in my experience, significantly quicker than any other house plant I can think of (except for one of my Anthurium Clarinerveums).
We generally say to repot every year or so but Monstera often need repotting sooner. Once you need to repot, it’s safe to assume you’ll need to start adding more fertiliser.
Monstera also tend to go dormant in winter, so don’t fertilise them if they’re not growing.
What fertiliser is best for Monsteras?
Monstera aren’t really picky about what type of fertiliser you use. You can go for an all-natural seaweed or fish emulsion if you like, or you can go to your local garden centre and get some standard house plant fertiliser – Miracle-gro or whatever else they have.
Monstera have been grown as house plants for centuries. One of the reasons they’re so popular is that they’re happy to adapt and not particularly picky. They’re an invasive species in many countries.
Unless you overfertilise your Monstera and cause damage to the roots, it won’t care what you give it.
If you’re overwhelmed by the choice of fertilisers, then go for something balanced – the bigger the numbers, the more concentrated the NPK (nitrogen, phosphorus, potassium) levels are. A gentle balanced fertiliser would be something like 5-5-5, or you could go for something stronger like 20-20-20.
Small to medium-sized plants only need the 5-5-5, but if you have a larger specimen, you may want to whip out the big guns.
Is coffee good for Monstera?
No.
Nor is it bad for your Monstera.
Coffee grounds have a pretty neutral pH, so adding them to your Monstera will have very little noticeable effect.
Coffee grounds do, however, add a bit of drainage medium to your soil, so if you’re a bit of an overwaterer, it may help.
What coffee grounds DO do (lol) is go mouldy. Gross. And they can attract fungus gnats. Neither of these are likely to cause any significant harm to your plant, but both are a bit unsightly and fungus gnats are extremely irritating.
There is some anecdotal evidence that adding diluted coffee (the liquid that you drink, not the grounds) causes your house plants to thrive, but what I suspect is going on here is correlational NOT causation.
It’s more than likely the same phenomenon as talking to your plants. It’s not the talking, and it’s not the coffee – it’s the attention.
I’m not accusing plants of being attention seekers, BUT if you take the time to talk to/pour coffee on your plants, you’re probably also taking the time to care for them in other small ways – dust the leaves, notice spider mites, rotate them.
If you take the time to regularly, e.g. pour coffee on your plant, you’ll notice subtle changes that you otherwise might not.
Are eggshells good for Monstera?
Eggshells, when broken down in the soil, can provide a plethora of nutrients that will give Monstera a nice boost.
You might be shocked then, when I advise that you DON’T put eggshells in with your Monstera.
The first and most important reason is that you’ll attract pests. Fungus gnats, of course, will rock up to any party that provides food. They are NOT picky, and will love an eggshell – heck, they’ll probably bring family, in the form of fruit flies.
You may also get regular flies – regular sized AND giant bluebottles – Yay!
Oh, and mice. Or rats. There’s a reason that you shouldn’t put eggshells in your compost UNLESS you’re sure it’s mouse-proof.
There is nothing egg shells can provide that you can’t get in a standard house plant fertiliser. They may seem free, but they come with their own issues. Don’t do it, guys.
BTW, if you have your own hens, you can just mash up the shells and give them back to the hens to eat. The ultimate in recycling.
Can you over-fertilise Monstera?
Definitely – you can over-fertilise any plant.
I recommend fertilising Monstera every six weeks, and I also recommend using half the amount recommended on the bottle.(That being said, I’m very much a member of the school of ‘just put a bit in’ rather than fastidiously measuring out the right amount.
I’m currently using the General Hydroponics Flora series (it’s fine to use on soil as well as leca), and I have to measure it out using a dropper.
What I tend to do is fill a 5 litre water bottle with water, and add 5ml of each of the fertilisers using a syringe tube thing. WHat I sometimes do is just pour in a drop. Whoops (but also all my plants are fine).
If you stick to the rules of halving the concentration of fertiliser and only fertilising every six weeks, you should never be in danger of over fertilising BUT I would recommend also sticking to the rule of not fertilising if your plant is compromised (i.e. has pests) or isn’t growing (due to winter, or some other issue).
Like all plant issues, an over-fertilising issue isn’t necessarily straightforward to troubleshoot. What looks like root burn could be root rot, for example. This is why I don’t fertilise if my plant isn’t growing –
a) A plant that isn’t growing won’t need fertiliser – you could damage it further
b) It either eliminates the possibility that the plant is being over-fertilised and if it has previously been over-fertilised, you know that that’s no longer the case.
Fertilising plants is like the HR department – extremely important and you’ll suffer without it, but also the first thing to go when times are hard.
In conclusion
House plant fertilising needn’t be complicated, and especially not for Monstera which are pretty chill as long as they have enough light, warmth, and humidity.
Don’t add human food to fertilise plants – you’ll end up with pests. It’s fine for outdoor plants, but remember that you have to cohabit with indoor ones.