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Coffee Grounds for Gardening | Everything You Need to Know

Using coffee grounds for gardening is all the rage right now. It's super savvy and an eco-friendly solution to support some of the plants in your garden. 

Not only will used coffee grounds add some amazing micro-nutrients to your soil, apparently, but they'll also even deter some pesky critters you don't want crawling around your flower beds or vegetable garden.

The trick, however, is to be slightly sparing. So, are coffee grounds good for plants? Let us find out. Here is everything you need to know about using coffee grounds for gardening. 


Coffee Grounds for Gardening Everything You Need to Know
Using coffee grounds for gardening

There are quite a few gardening hacks you can find online and coffee gardening, adding coffee grounds to your soil or compost is growing in popularity.

However, many experts warn that it won't benefit all of your garden plants because of the potential acidity and caffeine content. 

If you know how to use them right, they can be a valuable gardening asset and waste that doesn't end in your bin. Which means it's good for your garden and the environment. 

What Are the Benefits of Coffee Grounds for Gardening? 

Benefits of coffee grounds for gardening

While coffee grounds shouldn't wholly replace plant food or fertilizers, coffee grounds for plants are a great additive to your soil or compost mix. 

Coffee grounds are a fantastic source of not only nitrogen but potassium, phosphorous and other valuable micro-nutrients. 

Some garden experts even believe that coffee grounds can suppress diseases. 

Other benefits include: 

  • Repelling pests like mosquitoes, slugs and snails. 
  • Attract earthworms which are great for your soil. 
  • Reduce weeds. 
  • Deter cats from using your garden as a litter box. 

How to Use Coffee Ground for Gardening

Add It to Your Compost

One of the most common applications of coffee grounds is as an additive to compost

One of the most common applications of coffee grounds is as an additive to compost. It will add lots of nitrogen into your compost mix, promoting rapid vegetative growth and giving plants that healthy green colour. 

Coffee grounds are considered a green compost material so make sure you have plenty of brown compost material to balance it. In general, experts recommend a 4:1 ratio. 

If you are vermicomposting, coffee grounds are fantastic worm food. 

Coffee Grounds as Fertilizer

Coffee grounds work much like a fertilizer when adding directly onto the soil. However, it won't directly add nitrogen as it does when added to compost. 

Coffee grounds as fertilizer

It will improve your soil drainage, benefit nutrient retention, and add some extra aeration to the soil. Just be sure you mix it in well, as coffee grounds can clump on the top and then cut off water and oxygen flow to the roots of your plant. 

Contrary to popular belief, coffee grounds shouldn't affect the acidity if used to make a good cup of joe. Fresh coffee grounds, however, will. 

Make Some Mulch

Mulch rings or mulching the soil around your tree's base helps to keep your soil nutrient prosperous and retain moisture. Coffee grounds make great mulch when added with other organic, mulch materials. 

Again, it's important to note that coffee grounds can clump and suffocate your plant's roots, so make sure you use a concrete mix of other organic materials with the coffee grounds.

Using Fresh Coffee Grounds

Now, you'll need to note that the above applications make use of used coffee grounds. When coffee grounds are added to hot water, they lose a lot of their acidity and caffeine, which can be problematic and stunt plant growth. 

As such, used coffee grounds are generally recommended. However, if you have acid-loving plants, like hydrangeas or blueberries, they can happily handle some fresh coffee grounds.

Which Plants Like Coffee Grounds? 

If you're using small amounts of coffee grounds, most plants will benefit from the added nutritional push. In general, acidity-loving plants will enjoy it. Plants like: 

Azaleas like coffee grounds
  • Azaleas
  • Hydrangeas
  • Lily's
  • Hollies
  • Root Vegetables (like Carrots & Radishes)

If you're using coffee grounds in your mulch, plants like soybeans and cabbage will enjoy it. 

Which Plants Do Not Like Coffee Grounds? 

Some plants just can't take coffee grounds, and the caffeine content will negatively affect plant growth. Plants where grounds will inhibit growth include: 

Some plants just can't take coffee grounds, and the caffeine content will negatively affect plant growth
  • Tomatoes
  • Geranium
  • Asparagus
  • Chinese Mustard
  • Ryegrass

Can You Put Too Much Coffee Grounds in Your Garden? 

You can definitely add too much coffee grounds, which will have a detrimental effect on your plants. 

Caffeine can inhibit plant growth, and even though the caffeine content reduces radically when added to water, it's hard to tell how much is retained in the grounds. 

As a rule of thumb, just be sparing and spread your coffee grounds out over a large area or balance it with many other organic compounds.

Other Amazing Uses for Coffee Grounds

In your garden isn't the only place where you can use your old coffee grounds. Here are some other handy hacks you can use to avoid having to throw your coffee grounds away: 

Flea Repellent on Pets

The odor of coffee repels fleas. Simply rub some coffee grounds into the fur of your pets before shampooing. Not only will it repel fleas, but it might even make your furry friend's coat shinier. 

Eliminate Foul Odors

Coffee grounds can help to eliminate foul smells. Pop a small bowl of coffee grounds in your fridge to remove smells from spicy or spent meals.

You can even keep a small bowl of coffee grounds next to the sink and use it to wash your hands after cutting things like onions or garlic. 

Use It as a Cleaning Scrub

Coffee grounds are quite abrasive and even have anti-bacterial functions. Use it to clean sinks, basins or even your bathroom.

Just be sure to avoid any porous surfaces as the coffee may cause stains. 

Use it On Your Body

A good old coffee scrub is a great way to exfoliate the skin and hydrate. Simply add your coffee grounds to some coconut oil and honey and use it in your bath or shower.

Other Kitchen Scraps You Can Use in Your Garden

Other kitchen scraps you can use in your garden

Coffee grounds aren't the only kitchen scraps that you can start re-using to benefit your plants. Do you know how they say "Waste not, want not"?

Well, here are some other amazing things you can start to re-use: 

  • Eggshells. Clean and keep your eggshells, crush them and mix them into your soil for that extra kick of calcium. 
  • Banana Peels. Not only a natural fertilizer, but banana peels will also repel pests like Aphids and Fruit flies. 
  • Orange Peels. Citrus peels aren't recommended for composting but leaving a small piece of peel on the top of your soil will keep pests and pets away from your plants. 
  • Nutshells. Pistachio or peanut shells are a great way to improve your soil drainage when crushed and combined to your soil. 

If you want to grow your own Pistachio at home, here is our Complete Pistachio Growing Guide

Wrapping Up Coffee Grounds for Gardening

In general, the best application for your coffee grounds is in your compost. It'll be the best way to make sure they benefit your plants with plenty of nutrients, without over-powering them or stunting growth. 

Especially when adding straight to the soil, make sure you're sparing and don't allow the grounds to clump up and cut off oxygen to your plant roots. 

Whichever way you decide to use them, you will no longer need to worry about wasting your coffee grounds. Start using your coffee grounds for gardening, and so much more today. 

About the Author Ann Katelyn

I'm Ann Katelyn, Creator and Chief Author of Sumo Gardener. Since I was a child I've always been fascinated with plants and gardens, and as an adult this has developed into my most loved hobby. I have dedicated most of my life to gardening and started Sumo Gardener as a way to express my knowledge about gardening with the hope of helping other people's gardens thrive.

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