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Coffee Tips

Are Coffee Grounds Good for Plants?

It is undeniable that a morning cup of coffee comes with numerous benefits to the human body. It helps in waking you up and boosting your energy levels. However, the benefits of coffee are not limited to the human body. Coffee is also beneficial in the garden. Rather than throwing away used coffee grounds, you can reuse them in your garden to benefit plants in numerous ways. So are coffee grounds good for plants? Keep reading to find out.

coffee grounds for plants

Essentially, left-over grounds from your favorite coffee maker contain a significant amount of nitrogen, phosphorous, and potassium. These properties are similar to what you find in most fertilizers. That is why coffee grounds are perfect for various gardening activities. Here are some of the best ways to use coffee grounds in your garden.

1. Composting Coffee Grounds

One of the best ways to make good use of coffee grounds that would have ended up in a landfill is composting. Composting used grounds helps in adding nitrogen to a compost pile. It is a simple task to do. You can simply throw used grounds onto a composite pile or mix them up.

You can also compost used paper coffee filters. However, remember that coffee grounds are considered a green compost material. Thus, you should balance them by adding brown compost material.

Since coffee is a highly acidic compound, it can easily interfere with the pH balance of your compost pile. Thus, you need to be cautious about the amount of coffee grounds you are adding to your compost. Avoid adding excess grounds. Preferably, layer equal amounts of leaves, grass clippings, and ground coffee when composting used grounds.

2. Using Coffee Grounds as Fertilizer

Besides compost, you can also use left-over coffee grounds as fertilizer. Many gardeners prefer placing grounds directly on the soil when using it as fertilizer. However, it is important to note that although coffee grounds add sufficient nitrogen to compost, they do not add it to the soil right away.

The main benefit of applying coffee grounds to the soil as fertilizer is that it adds beneficial organic matter to the soil. The organic matter helps in improving soil aeration, water retention, and drainage. Also, the grounds help beneficial soil microorganisms to thrive for enhanced plant growth.

Also, ground coffee lowers the pH of the soil as they raise its acidity. Thus, acid-loving plants thrive when you feed them with coffee grounds. It is often possible to do this with fresh coffee grounds while they are still unwashed. Used grounds are neutral and will not boost the soil acidity significantly. Regardless, when using ground coffee as fertilizer, work them into the soil near the plants for maximum results.

3. Keeping Pests Away

You can use coffee grounds to create a barrier for snails and slugs. Coffee grounds have abrasive properties. Thus, placing grounds close to slug-prone plants can help in saving them from snails and slugs as they will avoid the area.

However, some scientists argue that this method is not always effective. Thus, try another method if coffee grounds fail. Also, some cats often dislike the smell of ground coffee and might avoid using the garden as their litter box. Regardless, try it and see whether it will work for you.

4. Feeding Worms

Worms are known to love coffee grounds. Thus, you can add left-over grounds to the worm bin once in a while, preferably weekly. However, do not add too many grounds at once as their acidity may bother the worms. A cup of grounds weekly is enough for small worm bins. Besides the worm bin, earthworms present in the soil will also get attracted to the grounds when you mix them into the soil.

5. Feeding Acid-Loving Plants with Coffee Grounds

Used grounds are less acidic. Fresh (unused) coffee grounds are more acidic and offer more benefits to acid-loving plants. Acid-loving plants include carrots, azaleas, hydrangeas, blueberries, rhododendrons, radishes, lilies, and roses. These plants can thrive better when you throw some fresh grounds near them.

If you have coffee grounds getting old in the pantry or a brand of coffee you did not like, you can use it on your acid-loving garden plants.

However, tomatoes dislike fresh grounds. Do not throw coffee grounds near tomato plants. Grow tomato plants in a separate area of the garden where you do not plan to throw coffee grounds.

Also, avoid using coffee grounds on very young plants and seedlings. Fresh grounds have the most acid and caffeine content. Caffeine can stunt the growth of young plants. Also, avoid using fresh grounds near pets.

Dissenting Research about Using Ground Coffee in the Garden

A research study published in 2016 found that using left-over coffee grounds on plants such as viola, radish, sunflower, leek, and broccoli led to poorer growth regardless of the soil type, either with added or without fertilizer. The researchers argue that plant-toxic compounds present in coffee may have led to poorer growth.

From the research finding, coffee grounds may not be ideal for certain types of plants. Thus, if you are not getting good results with coffee grounds on some plants, you may avoid them and only use them on the plants that show good results.

Also, the research found that coffee grounds improved water retention and decreased the growth of weeds. Thus, coffee grounds are beneficial for the soil and the plants that like them.



Gardening and coffee grounds go together. Whether you prefer using coffee grounds as fertilizer or for composting, you will realize that ground coffee gives the garden a major boost as it does to your body. Just ensure you test the pH of your soil before applying coffee grounds. That way, you will decide whether to use acidic fresh grounds or less acidic used grounds. Regardless, use coffee grounds on acid-loving plants and avoid it on plants that dislike acid.


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