coffee grounds being added to soil

I really am not fond of waste and I’m always looking for ways to be more eco-friendly so when I discovered that you can use old coffee grounds in your garden I had to give it a go.

Reusing coffee grounds to help make compost, feed certain species of plants, repel weeds, and deter pests not only helps your garden grow but also provides an eco-friendly way to get rid of the coffee grounds once you’ve enjoyed your morning coffee.

Here are some of the many ways to add coffee grounds to your gardening routine.

Coffee Grounds Make a Rich and Fertile Compost

Plants need a rich variety of nutrients to grow strong and healthy. Although some of these compounds are found in the soil in your garden it’s often the case that you need to add a little something extra to give your plants those much-needed building blocks.

Compost is that magic ingredient that can elevate your plants from dull and depressed to shining with vigour and vitality. You can buy compost ready-made in bags but it’s much more eco-friendly (and rewarding) to make your own.

Compost can be made from household food waste as well as from using garden waste like hedge trimmings and grass clippings. It’s important to note that you should not add any grass trimmings that contain weeds as these will thrive in the compost and re-appear when you want them least!

Coffee grounds make a really good addition to the compost heap as they are rich in nitrogen, potassium, magnesium, and phosphorus. All these elements help support healthy plant growth. Coffee grounds are acidic which can help some plants grow but can also hinder other species.

This is why it’s best to dilute the coffee grounds with plenty of other food waste so that it’s not too concentrated. Adding eggshells to the mix can help balance out the nitrogen content with plenty of calcium.

 Another benefit of adding your used coffee grounds to the compost bin is that earthworms love them. They attract these little guys to come to join the party and they work to mix and turn the material in your compost heap, which aids with its decomposition.

 Overall, coffee grounds can be a beneficial addition to the compost heap. Just make sure you add them alongside plenty of other material. You can even add the paper filter as well as these breakdown naturally too and this makes an eco-friendly way of disposing of them.

Can You Use Coffee Grounds as Plant Food?

Coffee grounds make a great addition to compost so it would make sense that you can also use them as plant food?

The truth is, there are only certain plants that appreciate a sprinkle of coffee in the morning. These plants are acid-loving species like Azaleas, Blueberries, Hydrangeas, and Rhododendrons.

Used coffee grounds tend to have a slightly acidic to neutral pH as a lot of the acidic components are dissolved into liquid as you brew coffee. For acid-loving plants, it can be even more beneficial to add fresh coffee grounds to the soil around these species if you’re really trying to acidify the environment.

 In the same way that some plants love coffee grounds, other species cannot tolerate them. Sprouting weeds and small seedlings are sensitive to this so this means you can use coffee grounds as a weed killer for those pesky plants. Add plenty of coffee to areas that you want to keep free from unwanted weeds but don’t let it get too close to the plants you want to support unless they’re acid-loving species.

Magic Hydrangeas

Hydrangeas are a beautiful addition to any garden with their stunning clusters of bright flowers. They flower in a beautiful spectrum of colours from white through pink, purple, blue, red, and sometimes pale green.

 The magic secret with these flowers is that the pH of the soil can actually influence what colour they turn out to be. A more acidic soil of pH 6.0 or lower gives blue flowers whereas a more neutral to alkaline soil of 7.0 and above produces pink ones.

You can use coffee grounds to acidify the soil if you prefer blue flowers and watch in delight as the colour emerges when they bloom. Just be wary of how much coffee you use as too much nitrogen in the soil will cause healthy, lush growth of the plant but also inhibits the number of blooms on the plant.

Coffee Grounds for Pest Control

Garden pests can really have you at your wits end when it comes to caring for your plants. You can quickly end up in a bind where you really want to protect all your hard work but also don’t want to resort to harsh measures.

Coffee grounds can act as a natural pest repellent for ants, slugs, and snails. Scatter the grounds as a barrier to protect your prized vegetables. The coffee grounds can also help deter larger pests as well like deer and rabbits. They are put off by the smell of the grounds so are more likely to leave your garden alone.

 Another benefit of coffee grounds is that cats are not fond of them. If you have a problem with cats pooping in your flower beds or digging up your vegetable patch then use coffee as a natural deterrent.


Coffee is wonderful stuff but when you’ve finished drinking your delicious cup of joe in the morning, don’t throw the grounds into the bin! Add them to your compost heap so that they can break down organically and add a lot of goodness to the mix. You can also save them up and use them to prevent weeds from growing or use them to deter annoying garden pests.

Whatever you decide to do with your coffee grounds, just make sure you’re using them on acid-loving plants (unless you’re trying to avoid weeds!) If you don’t drink coffee made with a coffee maker at home  you can often get bags of coffee grounds from your local cafe. 

There’s nothing more therapeutic than tending to your garden, the satisfaction comes initially after the work but even more so when you see your plants flowering, your vegetables starting to take shape, and your bushes filling out.

For more natural pest control check out this DIY Natural Garden Bug Spray which is great for deterring aphids, mealybugs and whiteflies.