Recycling and reducing waste is more important than ever. In US alone, people drink around 400 million cups of coffee each day. That’s a lot of caffeine, and a lot of coffee grounds to throw away as well. Perhaps we do not have to throw it away though, and can use it as a fertilizer of our succulents instead. Will it work though? And do succulents like such a practice?
The answer to this question isn’t as simple as it seems. Succulents like slightly acidic soil, and coffee grounds add acidity to the soil. But it also depends on whether you use raw or cooked coffee grounds, in what quantity, and how you apply it on your succulents. We will dive into details in a second, but let me give you a quick answer first: Succulents like coffee grounds, if you fertilize them withe them sparingly, and do it in a right way. Let’s have a look at the details.
Succulents in general do not like too much fertilization, and coffee grounds are no exception
Succulents are native to semi-desert and desert areas around the world. As you can imagine, people do not run around the desert fertilizing the plants, or throwing coffee grounds on them. And yet they thrive and even flower when conditions are favorable. That’s because succulents thrive in neglect. Give them a short rainy season once in a while and desert sun, and they will do well, and sometimes live for centuries (which is the case with Barrel Cactus or Desert Rose).
Bearing this in mind, it is logical than excessive fertilization can only cause harm to succulents. If you think that you can just throw the coffee grounds each morning to one of the few pots with succulents you have at home, you are wrong. Succulents like slightly acidic soil, and they enjoy nutrients in some quantities, including nitrogen and phosphorus and potassium, all present in coffee grounds. But a succulent pot is not a rubbish bin. Adding so much coffee grounds over an extended period to the pots will result in excessive acidity of the soil (and other problems, more on them later), and subsequent issues. You can use coffee grounds for succulents, but in moderation.
Raw coffee grounds can be toxic to many plants, including succulents
Depending on how you prepare your coffee–and what type of coffee you drink, you are left with either raw or cooked coffee grounds. You may think it doesn’t make much difference for the plants, but it does. Raw grounds are extremely acidic and you may kill your succulents with them, especially if you add them to the soil regularly. To stay on the safe side, you should always use just cooked coffee grounds.
It also makes sense adding coffee grounds to your compost first, letting the nature do its magic, breaking them down to smaller particles, and mixing with other things you deposited in your compost. Just then you can add the final mix to your plants, including succulents. It is much safer to be honest, though I understand it is a lot more work, and it may not even be possible if you live in a flat, and do not have some amazing kitchen composter at home.
Plonked coffee grounds can harden and prevent water from entering the soil–you need to apply them correctly
Careless throwing of coffee grounds on the top of your succulent pots at random may result in a disaster. Coffee grounds, when they aren’t mixed into the soil and simply stay on the top of the pot, will harden quickly, forming an almost impenetrable layer, preventing water from entering the soil. What happens is that you water the succulents but most (or all) water stays on the top, not reaching the roots of the plant. What’s more, this can result in stem rot, because succulents do not like when there’s always water around the stem.
Hence it is pivotal to apply coffee compost properly on succulents. Gently stir it and mix it lightly to the soil, spreading it evenly in the pot, in the top two inches. It is even safer adding it to water, for example two tablespoons to one gallon, mixing it properly, and then watering your plants with this “homemade liquid fertilizer”. Do not overdo it though, and use just cooked coffee grounds. Less is often more with succulents.
Coffee grounds help aeration in the soil, but they also retain water
For most plants, coffee grounds work like a miracle–they add nutrients to the soil, help with aeration, and retain water. Most plants will love this, but succulents won’t love the last part–the water retention. We should not forget that root rot is the most common reason why people lose their succulents. Root rot happens when the soil is almost always wet, which can be caused by a variety of factors:
- Over-watering of the plant
- No drainage in the pot
- Bad soil mix–one that retains too much water
Adding coffee grounds in quantities to your succulent soil, or to any pot in particular, can result in significant changes in water retention properties of the soil. If you overdo it, you can easily kill your succulent in this way. The process is slow, and you may not notice anything for the first few weeks. But the roots bathing in water will eventually start to rot, and once the rot progresses to the body of the plant you can say goodbye to your succulent…
Final verdict on whether succulents like coffee grounds
Nothing is black and white in the world of succulents. Sure, these versatile plants like coffee grounds as an occasional fertilizer, but only if we talk about cooked grounds, and only if you apply them to the plant properly, and in a moderate quantity. I hope you know how to do it now, and what mistakes to avoid. If you aren’t sure what you are doing, it is always safer skipping the fertilization with coffee grounds, and throwing them to a communal compost bin instead…
May also interest you: Is peat moss good for succulents?