Using coffee grounds on plants has become very popular, but are coffee grounds good for Christmas cacti?
Coffee grounds can be beneficial for Christmas cacti, as they are slightly acidic (when fresh) and contain moderate amounts of nitrogen. However, there are some drawbacks to using coffee grounds as they don’t contain a full nutrient profile and can affect the consistency of the soil.
It’s important to know both sides of the argument, as well as the different ways in which coffee grounds can actually be used on Christmas cacti so you can make your own decision.
Three Ways To Use Coffee Grounds On Christmas Cacti
Most people assume that coffee grounds are just added directly to the soil of plants, but there are other ways to add them as well that are more beneficial.
1. Adding Directly To The Soil
Coffee grounds can be added directly to the soil, and this requires the least work out of the three methods.
It needs to be mixed thoroughly with the soil to ensure that it doesn’t grow mold or form a hydrophobic layer on the surface. Don’t just add a layer on top of the soil and leave it.
2. As A Liquid Fertilizer
If you add coffee grounds to water and leave it in the fridge for a day or two you’ll create a nutrient-rich solution that can be sprayed or added to the soil of your Christmas cacti.
This is better than adding the coffee grounds directly to the soil as it doesn’t affect the consistency of the soil and it also reduces the chances of mold growing quite significantly.
3. Compost
Coffee grounds are super beneficial for composting heaps due to the ratio of carbon to nitrogen that they contain.
They can be used to improve your compost and then the compost can be added to the potting mix of a Christmas cactus to add lots of different nutrients.
The Good
Let’s take a look at some of the benefits of using coffee grounds on Christmas cacti to see what all the hype is about.
Acidity
Fresh coffee grounds are slightly acidic, which suits Christmas cacti as they enjoy soil with a slightly acidic soil pH between 5.5 and 6.2. Used coffee grounds can also be slightly acidic, but this varies between different types of coffee beans.
(Some) Nutrients
Coffee grounds contain a moderate amount of nitrogen – roughly 2% by volume – which is beneficial for Christmas cacti.
Nitrogen is useful because it is responsible for leaf development, and it is so important that it is one of the three essential nutrients that make up complete fertilizers.
Christmas cacti don’t technically have leaves, but their cladodes with benefit from additional nitrogen.
Efficient
It’s got to be said, having a use for coffee grounds after you’ve brewed your morning cup is definitely efficient.
Rather than throwing them away as most people do, using them for a houseplant is a great way to recycle and reduce your waste.
The Bad
There are two sides to the argument about using coffee grounds on Christmas cacti. I personally avoid using coffee grounds on my Christmas cactus, and hopefully, the points below will help you to understand why.
Attracts Pests
Coffee grounds tend to be moist, and this can attract pests such as aphids and fungus gnats.
This is especially true when coffee grounds are used to make a liquid fertilizer that is applied with a spray bottle but can also be the case if used grounds are added directly to the soil if they’re still moist.
Mold
Coffee grounds can grow mold pretty fast, and anyone who has used a coffee machine with a water tray probably knows about this already – or maybe I need to clean mine more often!
This can be avoided by adding the coffee grounds as a liquid fertilizer, but when added directly to the soil you can expect coffee grounds to grow mold pretty quickly.
Not A Full Nutrient Profile
Coffee grounds don’t contain significant amounts of phosphorus and potassium, the other two key nutrients that make up complete fertilizers.
This is quite important for Christmas cacti, which are known for producing bright flowers over the Christmas period. Phosphorus is responsible for flowering, so it’ll be less likely for your Christmas cactus to flower if you only provide nitrogen in reasonable amounts.
Caffeine Can Cause Issues
Studies suggest that caffeine can cause problems for plants, and coffee grounds do contain quite a lot of caffeine.
Used coffee grounds contain less caffeine but are also less acidic, so its a trade-off. In some cases you may notice that the caffeine has no effect at all, but it varies between plants.
My Experience
As a coffee addict and houseplant owner, I’ve been able to experiment with coffee grounds on a bunch of different plants including spider plants, pothos, anthuriums and many more.
It definitely makes sense to try and use coffee grounds for something useful, like on a houseplant, but in my experience, it can cause more problems than it will solve. I’ve found that using coffee grounds as a liquid fertilizer or adding it directly to the soil can quickly cause nutrient imbalances, resulting in yellowing and browning leaves.
Coffee grounds are quite prone to growing mold as well, which is something you need to think about if you add them directly to the soil.
What I Do Instead
If I had access to a compost heap I would add the grounds to that and use the compost as part of the soil mixture for my Christmas cacti.
However, since I live in an apartment I instead avoid adding coffee grounds to my plants altogether. In my experience, it’s better to use a complete fertilizer to ensure that all of the nutrient requirements are met.
I can see why some people decide to use coffee grounds, however, as it is quite efficient and reduces waste. If you want to give it a try I would use it as a spray, as mentioned previously, and start with small amounts.
Monitor the plant over a few weeks, and make sure you supplement with a complete fertilizer every so often so you aren’t neglecting other key nutrients.
FAQs
Does It Matter If You Use Decaf Or Normal?
Both normal and decaf coffee can be used for Christmas cacti.
Normal coffee obviously contains more caffeine, which can be detrimental to plant health. It does lose quite a lot of caffeine content when used though, at a trade-off in acidity.
Decaf coffee contains no caffeine but tends to be more acidic due to the Robusta beans that are used to make it. Whichever type you decide to use, the best advice is to start off with small amounts to see how your cactus responds to them.
Can You Use Tea On Christmas Cactus?
Most plants benefit from tea due to the nutrients that it contains.
Similarly to coffee, however, it doesn’t provide all of the nutrients that a Christmas plant needs in significant amounts. So, you can definitely try using tea directly on a Christmas cactus but don’t expect miraculous results.
