Monsteras are a popular houseplant because of their exotic looks and the fact that they’re incredibly easy to take care of. Among the many tips people share on how to take care of a Monstera plant is this curious recommendation of adding coffee grounds to its soil. But are coffee grounds actually good for Monstera?
Coffee grounds are good for Monstera based on anecdotal evidence. While they are no substitutes for regular fertilizers, they can help improve the soil structure. But one has to proceed with caution as they can also cause harm by promoting fungal growth and attracting fungus gnats.
We will explore this subject in detail in this article. We will look at all the benefits and possible harms of adding coffee grounds to the soil of your Monstera plant. Let us begin.
Coffee Grounds As Fertilizers: Myth or Real?
A lot of people seem to recommend the use of coffee grounds as fertilizers for house plants like Monstera. Science, however, shows that they have little to no effect on the development of the plant. But rather than being backed by science, this recommendation seems to be more of an old urban legend.
It isn’t hard to imagine how this mythmight have come into existence. For starters, coffee grounds are a recurring thing in any house. And they do share a likeness to compost fertilizers. So someone must have had a clever idea at some point. They probably added their coffee grounds to their house plant instead of discarding it.
The coffee grounds most likely had little to no effect on the plant, but the plant probably continued to grow at its own natural pace. This led the person to biasedly conclude that it must have been the coffee grounds they added to the soil that helped the plant grow. Simple tips like this often spread like wildfire because they don’t require much effort to try out. Fortunately, now you know better.
The Chemical Composition of Coffee Grounds
Before we look further into the benefits (or lack thereof) of coffee grounds on Monstera, let us first look at the chemical composition of coffee grounds. In particular, we will look at the amount of Nitrogen, Phosphorus, and Potassium, the three most important components in any plant fertilizer.
It is clear from the table above that Coffee grounds hardly contain any of the three chemicals to qualify as a proper fertilizer. But there are some other benefits to adding coffee grounds on your Monstera plant soil.
Benefits of Coffee Grounds on Monstera
There is enough anecdotal evidence that suggests adding coffee grounds to the soil can help improve the soil structure. Most people use perlite for this purpose, but coffee grounds are believed to have the same effect. That is the loosening of the soil and improving water retainment.
Anecdotal evidence also suggests that coffee grounds can help house plants like Monstera resist certain diseases. For this purpose, activated charcoal is the preferred chemical.
There is no science to back either of these claims up. To be fair, not a lot of scientific studies have been done on these matters, so you could try these for yourself to see the end result.
There are plenty of rumors suggesting that coffee grounds can increase the acidity of the soil, which can be harmful to the plant. These rumors probably arise from the fact that coffee in itself is rather acidic. But coffee grounds aren’t really that acidic. They have a pH level of 6.8, which is only slightly acidic. (A pH level of 7 is neutral, and the further down you go, the more acidic a substance gets.)
Coffee Grounds Can Also Be Harmful to Monstera
While there isn’t any real evidence to suggest that adding coffee grounds to Monstera plants can be harmful to the plant, we highly recommend that you proceed with caution.
First and foremost, coffee grounds can increase fungal growth. The rotting organic substance is a natural breeding ground for fungi. This can lead to your plant contracting fungal diseases. But it doesn’t just end there.
The main harm that coffee grounds can do for a Monstera plant is that it will attract fungus gnats. Fungus gnats are tiny fly-like insects that feed on the fungus in the soil. They are attracted to excessive fungal growth we discussed above.
The adult fungus gnat isn’t particularly harmful to the Monstera plant. They’re just there to feed on the rotting coffee grounds. But when they lay their eggs, that’s when the real harm starts. The hatching larvae are particularly voracious. And while their primary diet still consists of fungi, the source soon ends up depleted after which they resort to feeding on the roots of the plant.
It is also worth considering that even when fungus gnats aren’t directly harming your monstera plant, they will still make the scene look pretty ugly, rendering the whole point of keeping a house plant for show worthless.
Finally, adding too many coffee grounds can also increase the level of moisture retention in the soil to an unacceptable level. What this means is the soil is able to take in more water than usual, which can be a hard thing to detect for most people. So you could end up overwatering your plant, which leads to all sorts of problems such as root rot.
So What Can You Do With Coffee Grounds?
Don’t get rid of those coffee grounds just yet. While we have established that it may not particularly be a good idea to directly mix them to the soil of your monstera plant, there are still ways in which you could use them.
The first thing you can do is turn them into proper compost. If you have a compost bin set up, you can add the coffee grounds to the pile and wait until the whole thing gets naturally turned into compost fertilizer. The relatively high nitrogen content (2% per volume) of the coffee grounds can actually be beneficial to the whole compost.
And when you later add this compost to the soil of your monstera plant, it can help the tropical plant thrive.
Another thing you could try is brewing some compost tea that you can later add as a liquid fertilizer for your monstera plant. And preparing this compost tea is rather easy. All you have to do is add the coffee grounds to a pot of water and let it soak in there for a couple of weeks. During this period, you will have to occasionally stir the mix.
What this will do is release all the organic nutrients from the grounds into the water. The brewing compost tea will also attract a range of beneficial bacteria over this period. Then at the end of 2 weeks, simply strain the liquid over the soil of your monstera plant. This is a great way to fertilize and nourish your monstera plants while avoiding all the problems that come from adding solid coffee grounds that we talked about earlier.
While there is anecdotal evidence suggesting the benefits of adding coffee grounds on the soil of monstera plants, there is no scientific evidence backing these claims. In fact, if done carelessly, adding coffee grounds to the soil can do more harm than good. That is why, as with everything else, you must always proceed with caution, and be careful not to overdo it.