Why Is Coffee Good For Plants? Your Plants Need Some Coffee-Love Too!

Wondering why is coffee good for plants? Read on and give your plants some coffee love.

Why is coffee good for plants?
Plants benefit from the extra nitrogen

If you drink coffee and garden, you have a secret weapon up your sleeve: coffee grounds!

Coffee is highly nutritious for plants. While they won’t benefit from the caffeine the way we do, they will benefit from the extra nitrogen coffee adds to the soil. In a way, coffee is a lot like ordinary compost – except it breaks down much fast and won’t attract bugs. 

Furthermore, coffee works as a natural repellant to most animals. Cats, dogs, and many other mammals don’t like the smell! 

You can satisfy your plant’s nitrogen need and keep them from being dug up. 

While many people use coffee grounds for this purpose, you can also literally “water” your plants with coffee. (Should we call that “coffeeing”?)

Is Coffee Suitable For All Plants?

Top view of two cups of coffee with spoon on a wooden surface
Not all plants can benefit from coffee

No, not necessarily. While most plants will benefit from coffee, that doesn’t mean that all plants will enjoy growing in it. 

Excessive amounts of coffee grounds or coffee can add too much acid to the soil. Some plants love acidic soils. For instance, blueberries are acid-loving plants. Other species? Not so much. 

Watch your plants’ leaves for signs of yellowing. If the edges start turning brown, it could signify that the coffee is adding too much acid to the soil. In this case, you’ll need to switch to water for a while to wash away the excess coffee and then use a smaller amount of coffee in the future. 

We do not recommend using coffee for these plants: 

  • Tomatoes
  • Clovers
  • Alfalfa

For other plants, be sure to check whether or not they like acidic soil. If they don’t, skip on the coffee. 

What Kinds Of Coffee Are Suitable For Plants?

Ground coffee
Only use black coffee or plain coffee grounds

You should only use black coffee or plain coffee grounds on your plants. Just dumping leftover coffee into your house fern isn’t the best option in most cases. 

Added sweeteners are not suitable for plants. They can also attract bugs like ants, which can then attack your plant. Dairy should never be composted or added to the soil.

It can attract bugs of all sorts, like gnats and flies. It can also harbor some pretty nasty bacteria when you just let it sit out – even if it’s sitting in your plant’s dirt. 

Can You Put Coffee In Potted Plants?

Yes. If you follow all the guidelines we’ve discussed above, you can efficiently utilize coffee in most potted plants.

Just be sure you’re ready to deal with the drainage. You probably don’t mind leaving water sitting around in a drainage pot for a bit – but coffee is another story!

Of course, you don’t want to use it on all plants. Some don’t like the acid that coffee brings to the soil, which can cause serious problems. This is because coffee tends to get concentrated faster when used in a pot since there is limited soil to soak it up. 

I recommend using coffee less on potted plants, though the exact amount will depend on the type of plant. 

How Often Can You Water Plants With Coffee?

Generally, I recommend only watering your plants with coffee once a week. With that said, I also recommend checking your plant’s favorite soil type and keeping an eye on its condition. Some plants love coffee, while others will take a turn for the worst as soon as the fumes hit their leaves. 

Outside, coffee causes less of a problem. There is more soil to soak it up and spread it out. Inside, potted plants can be overcome by the downsides of coffee much faster. 

Start by adding coffee grounds sparingly. You can use a thin layer just under the top of the soil. Don’t add any more until the coffee is completely gone. This process will likely take a month or so. 

Burying coffee grounds is particularly useful for keeping pests out of your garden, and it also brings nutrients back into the soil. 

Author

  • Kristin first fell in love with coffee on a trip to Brazil - where she learned that the ground coffee found on American shelves was not the end-all. Today, she loves educating other coffee-lovers on how to make the best cup of coffee, no matter what you enjoy.