FREE Shipping on all orders over $50! Last Minute Gift? Give a Rockwood Coffee Gift Card -->>

Lush garden of vegetables

Use Your Coffee Grounds To Feed Your Plants

Keeping a garden alive is hard enough, especially if your Green Thumb is still a seedling.

Why can't I grow healthy vegetables? Well, one reason is that your soil isn't giving your plants the nutrients they need - see its not your fault after all! So how do you get your plants the right nutrients? The answer is coffee of course! 

Understanding exactly how coffee interacts with your plants will help you have a great harvest, a beautiful flower garden, and even help save the planet! 

What Does Coffee Do To Your Soil?

Generally, plants need three nutrients from your soil: nitrogen (N), phosphorus (P), and potassium (K) otherwise known as NPK. 

Your coffee grounds contain all three of the main sources of nutrients (NPK) as well as other micronutrients like magnesium, calcium, and zinc. Coffee is rich in nitrogen which is good if your soil is lacking, but can be harmful to your plants if they get too much. That's one thing we share with plants, too much coffee isn't always a good thing! 

I recommend using a soil test kit to help determine a few things about your soil before you share a cup with your green friends: 

  • What is the pH level of my soil?
  • How much nitrogen is in my soil?
  • How much phosphorus is in my soil? 
  • How much potassium is in my soil? 

Using a soil test kit will give you a better idea of what your soil needs, and if your used coffee grounds will give your plants the nutrients they're deficient in. 

How Do I Apply the Coffee Grounds to the Soil?

We'll discuss 2 types of coffee grounds: used and fresh. Coffee grounds that have been used to brew your coffee will cause your soil to be neutral on the pH scale, while freshly ground beans will cause the opposite effect, making your soil acidic. The soil nutrient-level and pH scale will help you determine just what your soil needs. Here are three ways to feed your garden with your used coffee grounds:

  1.  If you find that your soil is more acidic, brew your coffee and dump the grounds into a jar. I like to fill the jar up with water to help evenly disperse the grounds when fertilizing the garden soil. 
  2. If your soil is more alkaline but you need it to be acidic, you can use your stale coffee grounds (if you ever allow them to get stale!) or some of your fresh coffee grounds. 
  3. For those that are thinking about composting, you can put your used coffee grounds right into the compost bin or pile. This will give the compost a boost in the NPK that your plants will love. 
Jar of used coffee grounds for your garden.

Saving your coffee grounds not only feeds your plants but also helps reduce the waste you create! We like using our Diamondback Espresso Brew Bags instead of Keurig K-cups. These coffee tea bags are completely compostable and produce a delicious cup of coffee on the go.  

How do you know which plants to fertilize with coffee?

As we discussed earlier, you'll need to know what kind of soil (alkaline or acidic) you're starting with. Once you know that, then you can accurately determine which plants will need what kind of fertilization. 

A brief list of plants that will love more acidic soil: 

  • Tomatoes
  • Beans
  • Turnips
  • Blueberries
  • Elderberry 
  • Sweet Corn

These plants will love neutral to alkaline soil:

  • Asparagus
  • Cabbage
  • Kale 
  • Peas 
  • Rosemary

For Hydrangeas you don't need to test the soil - the blooms will tell you what kind of soil you have. If you’re growing hydrangeas and want to experiment with changing the color of the blooms:

  1. For blue blooms you’ll want to make your soil acidic, which means you’ll need to add fresh coffee grounds to your soil.
  2. If you already have blue blooms, add some used coffee grounds to get pink and purple blooms.

There are many more plants that thrive under more alkaline or acidic conditions. 

Final Take - How Do I Give My Plants the Nutrients They Need?

When you're planning out your garden, make sure to start feeding and cultivating the soil early to make sure its ready for all the wonderful plants you're going to grow! By incorporating these simple steps, you can give your garden the best shot at thriving: 

  1. Test your soil to find out the pH and what kind of nutrients you need to add.
  2. Save your coffee grounds (and other organic matter for compost) and use more environmentally friendly coffee.
  3. Research what kind of soil your plants need, whether they need alkaline or acidic soil.  
  4. Make sure to drink plenty of coffee - your garden will thank you! 

This article showcases just one example of how your amazing coffee grounds can help grow your garden and continue fueling your adventure. 

Older Post
Newer Post

Leave a comment

Please note, comments must be approved before they are published

Our House Blend Coffees

Close (esc)

Save 10% on your next order!

Become a Rockwood Insider to be the first to know about new coffee releases and upcoming promotions! Also, for joining, you will receive a coupon code for 10% off your next order!

Age verification

By clicking enter you are verifying that you are old enough to consume alcohol.


Shopping Cart

Your cart is currently empty.
Shop now