The #1 Thing I Do With Leftover Coffee (PS: I’m Not Drinking It)

My houseplants and I have something in common, we both love coffee! So I give leftover coffee to our houseplants, and they love it! It’s the number 1 thing I do with leftover coffee, and it has nothing to do with me drinking it!

Yes! Diluted coffee is an all-natural fertilizer for houseplants. 

Do you always have leftover coffee sitting in the coffee maker? Or, are you like me, who orders a grande iced coffee and somehow leaves it on my desk, and then I find it the following day feeling guilty for wasting $6!? I had no idea that my leftover brewed coffee was valuable fertilizer for houseplants such as your Fiddle Leaf Fig plants, Spider Plants, Snake Plants, Pothos, Philodendrons, Monsteras, Peace Lilies, and more!!

Did you know you can use your leftover coffee when watering your houseplants for extra nutrients? 

It’s True! Leftover coffee can be used as an organic natural fertilizer for most houseplants, and I highly recommend it! Just dilute it and use it! Diluting brewed coffee and adding it to the plants’ soil is way better than directly adding coffee grounds to the soil.

Thank You, Dallas, for sharing this on Instagram! I love it when my readers share their results on social media with me!

I started watering my houseplants with diluted leftover coffee a few years ago, and they went from happy to absolutely thriving! 

I got the idea because I was curious about how the coffee grounds contributed to our compost pile in the backyard. I throw as much as possible in our prairie area, and what doesn’t get eaten by the rabbits has helped grow wildflowers and other native Wisconsin plants.

I researched and found that coffee grounds are a great source of nitrogen for your soil. Nitrogen is important for houseplants because it helps them produce more leaves & stronger stems. I wanted to figure out a way to bring the same excellent nutrients I put outdoors inside for my houseplants. So, I decided to try using leftover coffee.

ALSO READ: How to Propagate Your Monstera Deliciosa

Now here is the important part! I do not use coffee grounds for my houseplants. I use diluted coffee. I do not use coffee grounds inside on my houseplants because the grounds retain too much moisture and often will start to grow mold.

Coffee contains small amounts of calcium and magnesium which are great for houseplants. I am so happy that I found this inexpensive natural fertilizer. But, you may be asking, do you just pour the coffee directly into your houseplants? Nope! I dilute it and ensure it is at room temperature before giving it to my plants.

Coffee for Houseplants

Diluted coffee acts as a slow-release fertilizer for houseplants. When used correctly, coffee fertilizer can improve plant growth and help your plants to withstand disease and pests better.

Brewed coffee contains beneficial nutrients such as nitrogen and potassium, essential for plant growth. The best way to use coffee as a fertilizer is to dilute it with water and add it to the soil around your plants.

You can also add coffee grounds directly to the soil, but this method is less effective than using diluted coffee and can cause mold or attract fungus gnats. Therefore, I do not recommend adding coffee grounds directly to your houseplant soil because it often does more harm than good.

But, if you have any leftover coffee, don’t throw it away- give it to your plants!

How much coffee should I use for my houseplants?

My golden ratio mixture is 1 Part Coffee to 5 Parts Water.

Drip coffee can potentially be pretty acidic, which can potentially be dangerous for your houseplants. The diluted coffee should be the color of a weak or watered-down iced tea. Be sure to wait until the coffee has cooled, so you do not burn or shock your houseplants.

I water my plants with diluted coffee about once or twice a week during the summer and once every 2 weeks during the winter or slow-growing months. My Fiddle Leaf Fig has been growing lush new leaves like crazy since I started the coffee watering regimen.

I have my Fiddle Leaf Fig in our sunporch which gets primarily West-facing sunlight. I give coffee to my Varigated Rubber Tree, too! I bought it from a houseplant seller in California, and the diluted coffee really helped it “perk” up after its trip via USPS all the way to Wisconsin!

ALSO READ: Avoid These 6 Common Houseplant Care Mistakes

Brewed Coffee as a Natural Fertilizer for Houseplants: FAQS

Can I use decaf coffee?

Yes, decaf coffee will work just as well as regular coffee.

Do I need to brew the coffee?

You’ll need to brew the coffee to extract the nutrients from the coffee beans.

Can I use instant coffee?

Yes, you can use instant coffee, but it’s not as effective as brewed coffee.

Which houseplants like coffee fertilizer?

I use the diluted coffee fertilizer on my ficus, rubber trees, umbrella tree, oxalis dwarf umbrella plants, lilies, ferns, monsteras, spider plants, snake plants, pothos (all varieties), and my fiddle leaf figs.

I do not use it on my cacti, succulents, or calathea plants because  I am worried about over-watering them.

**I live in the Midwest, and I feel more comfortable not watering them with the coffee fertilizer – but, if you see below in the comments a few plant owners have used coffee for their succulents with great success.

Are coffee grounds for houseplants good for indoor plants?

Coffee grounds can be beneficial for indoor plants because of their high levels of nitrogen micronutrients and relatively high water retention.

But, because they retain water so well, it can easily cause the top layer of soil to grow mold when used in the home with houseplants. That is why I ONLY use coffee grounds outdoors in my garden and my compost pile, and I ONLY use diluted coffee for my indoor houseplants.

I also use the coffee fertilizer in our container garden, veggie and herbs, and our raised planter garden in the summer. Keep in mind that using coffee grounds increases the moisture content in the soil, which is why it is suitable for vegetation that thrives in moist ground.

Which plants do not like coffee grounds?

The coffee grounds will change the pH of the soil and make it more acidic. Plants that dislike coffee grounds include roses, hydrangeas, gardenias, blueberries, carrots, and radishes.

Conclusion

Believe it or not, brewed coffee can make an excellent fertilizer for your plants. Coffee is high in nitrogen and potassium, essential plant nutrients.

The best way to use coffee as a fertilizer is to dilute it with water and add it to the soil. You can add coffee grounds directly to the soil, but this method is less effective than diluting the coffee. So the next time you brew a pot of coffee, don’t throw away any leftovers!

Feel free to ask questions in the comment section below! Have you given your houseplants coffee? Did you notice a difference? Please leave me a message in the comments. 🙂

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