Using coffee grounds on houseplants such as Anthuriums has become quite popular over the last couple of years, but do Anthuriums like coffee grounds or are they detrimental to growth?
Using coffee grounds on their own can be detrimental to Anthuriums for a number of reasons including changing the pH of the soil, encouraging the growth of mold and creating a nutrient deficiency. When used as part of a soil mixture as compost, however, coffee grounds do offer some benefits.
In this article, I’ll explain the reasons why I choose not to use coffee grounds on my Anthurium Andraeanum and how you can use them safely if you choose to do so.
Why Are Coffee Grounds Suggest For Anthuriums
Anthuriums, like most houseplants, benefit from the nutrients that complete fertilizers can provide. ‘Complete’ fertilizers contain the three main nutrients that Anthuriums require for growth – Nitrogen, Phosphorus and Potassium – which are often referred to by their chemical symbols as NPK.
Coffee grounds are often suggested as a natural substitute for fertilizer, but does this make sense? In order to understand why coffee grounds may not be the best option, it’s crucial to understand what nutrients coffee grounds actually contain.
What Nutrients Do Coffee Grounds Contain?
Coffee contains around 2% nitrogen by volume, and small amounts of calcium, potassium, phosphorus and other nutrients.
Nitrogen is beneficial for Anthuriums as it is one of the essential nutrients, but coffee grounds do not contain sufficient amounts of phosphorus or potassium which can lead to deficiencies.
Problems With Using Coffee Grounds On Anthuriums
I don’t use coffee grounds on my Anthurium and instead, opt for a complete fertilizer.
It’s up to you if you want to do use coffee grounds or not, but you need to be aware of the risks.
If you rely completely on coffee grounds to fertilize your Anthurium it will only provide significant amounts of nitrogen.
Too much nitrogen can be toxic to plants, and you will also miss out on the benefits of the two other main nutrients which are responsible for flower/fruit growth and overall functioning of the plant.
A popular way of adding coffee grounds to Anthuriums is to mix coffee grounds with water and leave the solution for a few days.
Afterwards, the solution is sprayed onto the plant similarly to how you can mist a houseplant with tapwater. The problem with this method is that the water becomes acidic when mixed with the coffee grounds.
Anthuriums prefer slightly acidic soil, and if you use a coffee ground solution frequently it can quickly make the soil too acidic. At pH less than 5, it becomes very difficult for Anthuriums to absorb the nitrogen, which essentially renders the whole process useless.
Coffee grounds turn moldy as part of the decomposition process, which is fine when using them in compost but not so fine if you apply the grounds directly to the soil as a mulch.
This is because it can spread into the soil and possibly affect the root system as well. Generally speaking, you want to avoid mold growth as much as possible when it comes to indoor plants.
How To Safely Use Coffee Grounds
If you’re still certain about using coffee grounds for your Anthurium I can understand – I use fresh coffee beans on a daily basis and it always feels like a waste to throw them away.
Luckily, coffee grounds make an excellent addition to compost, which can then be used as part of the soil mix when you next repot or propagate your Anthurium.
This is because of the nitrogen content which helps to speed up the composting process. So, if you make your own compost at home you should definitely consider adding coffee grounds into the mix.
Benefits Of Using Coffee Grounds In A Fertilizer
Coffee grounds don’t just speed up the composting process, they also add more nutrients to the compost which are then transferred into your Anthurium through the roots.
I personally stay away from using coffee grounds on my Anthurium as I prefer to use a complete fertilizing product that doesn’t have any of the risks associated with using coffee grounds on its own.
There are definitely some benefits, however, and if you want to give it a try then feel free. Some people have a lot of success with using coffee grounds, but you need to know the risks before you start or you may end up disappointed.