Skip to Content

10 Surprising Uses for Coffee Grounds in Gardens

For many of us, our morning cup of coffee is a necessity to make it through the day. But coffee can be more than just an energy boost for us! Did you know that utilizing used coffee grounds in gardens could be a boost for plants as well?

Go “green” and recycle your old coffee grounds while also keeping your garden healthy! Read on to learn about ten surprising uses for coffee grounds in your garden!

Ground coffee and beans  on wooden background

How To Apply Coffee Grounds to Your Garden

An important key to remember when adding used coffee grounds to your garden is not to dump them and leave. This will not aid in the growth of your plants, and it might even hinder them from thriving!

To add coffee grounds to your garden, begin by sprinkling them on top of the soil. Next, use a small rake to mix the grounds lightly into the soil. You can add a thin layer of leaves on top if you prefer.

The idea is to be sure the grounds are evenly mixed into the soil. If they are dumped, they will dry out, acting as a barrier to proper sun exposure. It will also prevent water and moisture from penetrating the soil beneath.

Coffee Grounds in Your Garden

Utilizing used coffee grounds for plants has been a common practice for many years. Read on to learn how to add them to your gardening routine!

1. Compost Them

Overhead view of coffee grounds being added to baby vegetables plant as natural organic fertilizer rich in nitrogen for growth

An easy way to use coffee grounds is to compost them!

Putting coffee grounds in your garden helps improve the soil’s water retention, aeration, and drainage. And they encourage microorganisms to thrive and will attract earthworms. So adding these to your compost is a great idea!

Keep in mind that compost requires a balance of greens and browns. Greens are nitrogen-rich, and browns are carbon-rich. Green materials include vegetables, fruit, and used coffee grounds. Brown material would be newspaper, dried leaves, and twigs.

A mixture of 1 part green to 4 parts brown materials is considered to be a healthy balance for your compost to be most effective.

Not sure where to begin with composting? Our post on The Best Compost Starter for 2023 will get you started!

2. Control Fungi and Bacteria

Hypholoma Fasciculare (Sulphur Tuft) Fungi growing on old wood in garden

In some studies, studies of putting coffee grounds in gardens have shown that it has properties that suppress fungal rots and wilts. It has also been observed to prevent select pathogenic fungi and bacteria from finding a home to flourish.

3. Alter the Soil pH

Soil pH meter and soil fertility meter for cultivation.

Many gardeners have found the overall pH of the soil can be reduced by adding the high acidity of coffee grounds to their garden. This means putting your used coffee grounds in your garden can help several varieties of plants to thrive.

However, research hasn’t fully proven this as effective yet. Try it to see if your garden’s soil benefits from a change in the pH balance!

4. Spoil Your Roses

Coffee beans on table and white soap bar, bath skin cleansing sponge, fresh delicate pink rose flower, soft pastel color. Natural homemade body care scrub organic product.

Adding them to your growing roses is a popular use for coffee grounds! However, it’s best to use the grounds in moderation. Overuse of coffee grounds can squelch the roses, keeping them from flourishing.

Be sure you don’t add the grounds directly to the soil around the rose. This may burn the roots of the rose. Keep the grounds at a safe distance so they can sink into the soil surrounding the plant, not the plant itself.

The nutrients that coffee grounds have that are particularly beneficial to roses are nitrogen, calcium, potassium, iron, phosphorus, magnesium, and chromium.

Visit our post to learn more about Garden Roses.

5. Repel Snails and Slugs

Snail Muller gliding on the wet leaves. Large white mollusk snails with brown striped shell, crawling on vegetables. Helix pomatia, Burgundy, Roman, escargot. Caviar. Kisses of snails in strawberries.

Another benefit of using coffee grounds in your garden? Caffeine is toxic to slugs and snails.

The amount of caffeine left in the used coffee grounds isn’t significant. But it is enough to kill slugs and snails when they ingest it. The strong scent also appears to be a deterrent for them, keeping them away from your garden before they even get the chance to invade!

6. Care for Your Carrots

Adding coffee grounds to your garden can boost your carrots much-needed energy! And it works with other root vegetables, too.

Carrots absorb whatever nutrients are available within the soil. And coffee grounds have an abundance of nutrients ready to lend, many specific to the carrot plant.

To use the grounds with your carrots, work them into the soil before planting the carrot seeds. This will assure the carrots receive all the benefits the coffee grounds have to offer from the start!

Radishes are a great companion crop to grow alongside carrots. They will also enjoy absorbing the benefits of coffee grounds.

Looking for more tips on growing carrots? Visit our link on How to Grow Carrots.

7. Grow Some Mushrooms!

Different fresh wild mushrooms in bowl on black background, flat lay

Are you interested in starting a new hobby? One of the most surprising uses for coffee grounds is to try growing mushrooms in your leftover coffee grounds. You’ll need to order some oyster mushroom spawn to get started!

Grab a disposable plastic container or old plastic bottle, 1 gallon or larger. Be sure to wipe the inside with rubbing alcohol, to begin with a clean, uncontaminated surface.

Next, cut off the top of the container so you have a removable lid. Also, poke a few holes along the sides and the bottom to allow airflow and drainage as the mushrooms grow.

Next, grab a handful of ripped-up cardboard that you’ve allowed to soak in water for 1-2 days. Layer the cardboard on the bottom of the container. Sprinkle some mushroom spawn along the bottom, then cover with a thin layer of coffee grounds. Repeat these steps until the container is filled.

Place a final piece of cardboard on top and then replace the lid as snuggly as possible. Pull a clear plastic baggie overtop of the container to keep the moisture locked inside. Place a small dish beneath the container in case any water leaks out.

Put the container of mushroom spawn in a dark location for two weeks. Check the container periodically over this time to be sure the plant isn’t drying out. If it is, spray more water on the top and along the sides, allowing it to seep into the layers.

Once the mushrooms are budding, in about 2-4 weeks, move to an area with indirect light and humidity. Continue to keep the plastic baggie over the top and spray with water as needed. Eat them as soon as they’ve reached the desired size!

8. Fertilize the Garden

Unrecognisable woman in casual clothing holding a box of used coffee ground to use as compost in her garden.

Would you like to learn how to use coffee grounds as fertilizer? They are considered beneficial because they add organic material back into the soil. This can improve drainage, water retention, and aeration within the soil.

9. Feed the Worms

red californian earthworms in coffee grounds

The good news is that worms are attracted to coffee grounds! Worms are an important part of keeping a healthy garden.

Worms help process organic material, recycling the contents into nutrients. They can also help improve the overall structure of the soil beneath your garden. Their small bodies create tunnels below your plants, allowing air, water, and plant roots to grow!

10. Renew Your Plants

Coffee ground, Coffee residue is applied to the tree and is a natural fertilizer, Gardening hobby

Nitrogen is an integral part of a plant’s diet. It’s an essential part of photosynthesis, helps form chlorophyll, and helps with the growth of tissues within the plant. And it can help the plant form protein!

Coffee grounds contain approximately 1.45% nitrogen. Any amount will help make your garden thrive and be as healthy as it can be!

Fun Facts About Coffee

* Did you know that coffee drinkers live longer than those who don’t consume the beverage? Studies have shown that coffee can help reduce the risk of heart disease, type 2 diabetes, and Parkinson’s disease!

* Coffee was discovered around 850 CE by a goat herder named Kaldi. After noticing strange dance-like behavior from his flock, he decided to sample a taste of the berries from the evergreen bush where they grazed. He immediately felt a sense of exhilaration, telling everyone about his discovery!

* The Catholic Church has baptized coffee! In the 16th century, members of the clergy believed the dark drink to be satanic, causing corruption within those who drank it. It was banished from the church. However, Pope Clement VIII tasted coffee declaring it to have a wonderful aroma and flavor! He went on to baptize the drink, driving out its evil influences and making it a “Christian” beverage.

* Finland is the highest consumer of coffee worldwide. Up to 14% of Finnish men drink 10 cups of coffee per day!

Time to Care for Your Garden!

Are you inspired to save those coffee grounds to add to your garden? If you don’t consume the beverage at home, swing by a local coffee shop and ask them to save the grounds for you!

Are you looking for other ways to improve the health of your garden? Check out our post all about The Benefits of Keeping Certain Weeds in Your Garden!

Want more garden content? Visit our gardening page for in-depth guides, explainer posts, and great ideas!