The smell of freshly brewed coffee.
It’s a wonderful fragrance to start your day and take care of your lovely garden.
But before you throw those spent coffee grounds and head over to the garden, there’s something you need to know.
Those coffee grounds contain organic matter that is rich in nutrients for your plants. And that makes it a great choice for adding to your compost.
What are the benefits of using coffee grounds in the garden?
It will help you save money
If you or your family enjoy coffee, you get the grounds for free. Or you could get coffee grounds from coffee shops willing to dispose of them.
This will help you save some money that you would otherwise spend on fertilizer and compost material.
It will help reduce waste
You’ll use coffee grounds that are produced in your house or coffee shops.
Usually, these grounds are disposed of in the garbage and end up in the landfills. But when you use them in the garden, you’re reducing this waste and helping the environment.
It will help you make compost
Coffee grounds contain good organic materials, nutrients, and texture.
These are the right ingredients in a compost pile to provide the organisms the right environment. The organisms break down the organic materials with the right amount of moisture and nutrients.
And the end result is rich, organic compost that makes your garden soil friable.
Why should you not use coffee grounds in the garden?
We just saw the wonderful benefits of using coffee grounds so why not use it directly in the garden?
The problem comes down to caffeine.
This substance is a major part of beans like coffee and cacao (that’s used to make chocolate). The problem with caffeine beans is that they use allelopathy to prevent surrounding plants from growing so that they can hog the resources like nutrients and water.
So imagine adding the coffee grounds high in caffeine to your soil. That will worsen the growth of your plants.
Another problem with coffee grounds is they can be highly acidic.
This might not be a problem for plants that like acidic soil like hydrangeas, azaleas, and blueberries. But for other plants, this can hamper the growth of flowers and fruits.
Coffee grounds have a good texture that makes it good to retain moisture while draining out the excess. But it has antibacterial properties which can harm the good bacteria present in the soil.
How can you use coffee grounds?
Now you know why you should not use coffee grounds in the garden.
But that does not mean they don’t have their purpose.
Coffee grounds are rich, organic matter that has the right texture to retain sufficient moisture while draining out the excess. They also have plenty of nutrients like nitrogen, phosphorus, potassium, magnesium, and copper.
This makes it suitable as an addition to your compost pile for making compost.
Coffee grounds are a green matter that provide a high amount of nitrogen to the compost. That’s why you’ll need to mix one volume of coffee grounds with three volumes of brown matter like dried leaves, straw, or wood chips.
Where can you get coffee grounds?
If your household consumes a lot of coffee, you’ll have all the coffee grounds that you need for your compost.
But if the consumption is low, you’ll need to find some alternate sources.
One of the best sources of coffee grounds is Starbucks because they have a Grounds for Your Garden program. This means select stores will keep the spent coffee grounds and give them to gardeners on a first come first serve basis.
This is available in select stores that follow the program and you’ll get the coffee grounds in reused bags that were used to bring in the coffee beans.
The benefit is that Starbucks does something good for the environment because the coffee grounds don’t reach the landfills and are reused instead.
If you don’t have a Starbucks nearby that will save the coffee grounds for you, don’t worry. You can ask your local coffee shops to do the same. Just tell them to keep the coffee grounds for you rather than throw it away.
You can do the same with convenience stores, gas stations, restaurants, and diners that brew a lot of coffee. Ask them to set aside the coffee grounds instead of throwing it in the waste.
If you work at an office, you can collect the coffee grounds from the coffee machines. Or request your colleagues to put their coffee grounds in a bin that you use for collecting the waste.
How to store coffee grounds?
It’s great to get coffee grounds from stores and restaurants but you might end up with an excess.
So how can you store it for your next use?
You can’t just put it in containers and store it. That’s because there’s a lot of moisture in the coffee grounds. This will make it get moldy and smelly. You know this has happened with the smell and the color of the coffee grounds becoming greenish, bluish, or white.
The coffee grounds with mold can be used in the compost pile without any problems but it’s not meant to be stored.
To store the coffee grounds for a long period of time, you’ll need to dry them. You can do this in the sun during summers but that’s not possible in winter. The option there is to dry it in the oven after your cooking is done.
To dry the coffee grounds you can push it through a large sieve so that the grounds separate into a fine powder that looks similar to coffee.
You can then use a large tray and place a few layers of newspaper on it. Then you can lay a couple of inches of the coffee grounds on the newspaper.
Keep them to dry in the sun or oven and you should check on this after a few hours. Mix the coffee grounds with strips of paper and bring the bottom layers to the top so that the air and light reach into the entire layer.
Once the coffee grounds have dried out you’ll notice a change in the texture and color.
You can store the coffee grounds in a dry, air-tight container made of plastic, glass, or metal. Cover the top of the container with paper to drain out any excess moisture.
This method of storing the coffee grounds will ensure they last for a few years without suffering from any mold.
What plants tend to like coffee grounds?
We discussed why it’s not a good idea to directly put coffee grounds into the soil and instead use it as part of the compost.
This means coffee grounds are not the best when it comes to using as mulch or fertilizer because they tend to be acidic and lower the pH level of the soil.
However, there are plants that grow in acidic soil and they would love to have a pH of 5.5 or lower. It could be useful to use coffee grounds to amend the soil that these plants grow in.
Such plants include azaleas, blueberries, hydrangeas, rhododendrons, holly, gardenias, cranberries, roses, radishes, carrots, and citrus fruits.
So don’t throw away those coffee grounds.
It’s not the best to use them as mulch or fertilizer but they do make a great part of your compost.
And it’s free to get the coffee grounds if you know where to find it.
Start looking for it because your garden will be happy.
Here are some of my favorite container gardening tools
Thank you for reading this post. I hope it helps you with your gardening needs. I’ve listed some tools below that can help you with container gardening. These are affiliate links so I’ll earn a commission if you use them.
Gardening Gloves – I find the Pine Tree Tools Bamboo Gardening Gloves really good for both men and women. It’s made from bamboo so helps absorb perspiration. They are also comfortable and fit very well.
Containers – You know picking the right container is crucial for your container gardening. I’ve written a detailed post on the best containers you can choose from. If you’re happy with a plastic container, you can check out the Bloem Saturn Planter.
Watering Can – This is a must-have tool when you’re growing plants in pots or grow bags. It helps to water the potting soil without splashing on the foliage. The Kensington Watering Can is stylish, strong, and can provide precision when watering potted plants.
Trowel – Garden Guru Trowel is my favorite because it’s durable and comfortable to use. My gardening friends really love having a trowel because they use it for digging soil, mixing fertilizer, moving seeds, leveling out the soil, mixing compost or mulch, and also dividing tubers
Bypass Pruner – I really like the Corona Bypass Pruner because it’s durable and gives a clean cut that helps plants recover faster. If you’re looking for something cheap, get the Fiskars Bypass Pruner that is really good as well.
To see an extensive list of the best container gardening tools gardeners recommend, check out this resource that I made for you.
Kevin is the founder of Gardening Mentor, a website that aims to teach people to grow their own food in a limited space. As a self-taught gardener, Kevin has spent several years growing plants and creating gardening content on the website. He is certified in Home Horticulture and Organic Gardening by expert gardeners from Oregon State University.