Introduction: Coffee Grounds... a Gardeners Asset

About: I am medically retired. Forced to stay home, I hobby. I sew clothes, clothing reconstruction + some home decor. I also cook+ bake. I like to build things. I have a huge passion for mosaics and i have just rece…

Ahhhh liquid gold. Morning would not be the same without you. Coffee is loved the world over. We can't drive for long without seeing  those bright signs "Tim Horton's". Here in Canada it's our favorite stop. The Americans have Starbucks. No matter where you are, a coffee house awaits. Annual coffee consumption worldwide is estimated to be around 400 billion cups, or 12,000 cups per second. Coffee is the most popular hot beverage in Canada with an estimated  total of 14 billion cups consumed annually. It is also estimated that over 400 million cups of coffee are drunk everyday in the US. As with all things, coffee consumption has a grounds. I love my coffee and I always have coffee grounds available.

So what do we do with these coffee grounds? There are many different uses for coffee grounds, especially in the garden. Personally I save mine and mix them with the garden soil. They are beneficial to improve soil quality. They add nutrients to the soil which in turn feeds your plants. Coffee grounds even help keep certain molds and fungi out of your garden. They also help repel unwanted visitors like snails, slugs and cat.

Step 1: Recycle the Grounds

Why Recycle ?

When coffee grounds and other food wastes are sent to landfill, they decompose to produce methane. Methane(CH4) is a greenhouse gas with more than 20 times the global warming capacity of carbon dioxide. It's also a potential source of hazardous pathogens and organic leachates that can contaminate surface and ground water. It is also a loss of an intensive source of nutrients and energy as well.
With coffee being the beverage of choice of millions of people it is no wonder that so many coffee shop chains have become so popular. Coffee grounds are a large portion of waste at coffeehouses. A study by the Oregon State University Extension Service estimated that coffee shops in Lane County, Oregon produce 500 tons of grounds per year. This is only 1 community of a little over 300.000 population. Imagine the mountains of grounds being produced in large cities. The tonnage would be unimaginable. In comparison, our personal  household coffee grounds from your daily pot or single cup brewer seems inconsiderable, but this waste adds up over time.

If coffee grounds are recycled, however, valuable organic matter and nutrients can be recaptured for use as soil fertilisers, conditioners and mulch. Methane can also be captured for electricity generation but this is another topic all together.

There are many ways to recycle coffee grounds. The best way of course is to use them in your garden. However there are other uses for coffee grounds which will be mentioned later.

Yes the Keurig, Tassimo and Nespresso machines are convenient but the end products end up in landfils. So please make the effort to recycle after you enjoy your cup of deliciousness :). All those brewing cup like the K-cups, Tassimo disks, and Nespresso cups can be recycled. You can remove the lids, remove the coffee grounds and recycle the cups themselves. They are either made of plastic or aluminum, so off they go to the recycle box. Personally I not only recycle the coffee grounds in my Nesspresso cups. I repack the cups themselves...but that is another tutorial :)

Step 2: Composting

Composting is a great way to use up those grounds. Think of fresh or unused coffee grounds  as ‘hot or green manure’ that needs to be aged. When paired with "browns" like leaves, twigs,straw or even coffee filters, coffee is the perfect catalyst for healthy decomposition, which can speed up the composting process. Coffee grounds help to heat up the compost pile. This additional heat helps to speed up the decomposition of the other components such as kitchen waste, leaves, grass clippings, etc.  Composting occurs quickly in piles that reach high temperatures. Sustained heat also kills pathogens and weed seeds. During a study reported by Oregon State University Extension Service, composting specialists found that coffee grounds were more effective than manure at maintaining high core temperatures during composting These temperatures ranged from 135 to 155 F and lasted for two weeks. For backyard composters, coffee grounds provide a convenient and effective nitrogen source without the pathogen concerns of manure handling. It is said that the compost pile’s content of coffee grounds should not exceed more than 25% of the compost pile or the balance will be off and the speed of the decomposition will be affected.
The end product of composting yields a nice ‘black gold’ nutrient rich compost that will make your plants, vegetable garden or lawn very happy.

For those that don`t drink coffee, used grounds can be obtained from many coffee houses for free.

Step 3: Vermicomposting

Coffee grounds are also a preferred food of composting worms.

This is a subject i know little about. However, vermicomposting or composting with worms, is becoming more and more popular with serious gardeners all over. Vermicomposting  is the decomposing of organic waste with red worms. It is a very convenient way of composting for apartment dwellers, school staff and students, persons with disabilities, office workers, elderly persons and anyone else who would have difficulty maintaining an outdoor compost pile.
Vermicomposting creates a fine black granular compost called "castings". Worm castings are an excellent source of slow-release soil nutrients for your plants or lawn. They also act as an excellent soil additive that prevents the caking of soil in potted plants.   

Note: Redworms are not the worms that appear on roads and sidewalks after a rainfall.

Redworms are available for purchase from commercial growers, but can also be found for free in your own backyard! They are small, under four inches in length, and red, with alternating dark and light brown stripes. Redworms live in organic matter which is in contact with the ground. You will find them in decomposing leaves and decaying plant waste, manure, and the cooler decomposed parts of a compost pile. They generally live within the top four inches of soil, thus they are called the "surface feeders" of the earthworm family. Red worms eat their own weight in food every day. Coffee grounds being one of their favorite foods. However it should be mixed in as part of a balanced diet of cardboard, shredded paper, kitchen scraps, banana peels. Redworms eat almost everything that humans eat. 

Vermicomposting is done in bins made from plastic or wood. These containers are partially filled with bedding material, most commonly peat moss, shredded newspaper, shredded cardboard, straw or a combination of these materials.

You can find detailed information on how to start your own vermicomposting bin at

Step 4: Adding Coffee Grounds Directly to the Soil

Although composting is used greatly to recycle coffee grounds, adding them directly to the soil is another way to use them.
Coffee grounds contain nitrogen, calcium, magnesium, phosphorus, potassium, and trace amount of minerals including copper. These nutrients aid the plant’s growth. Our soil also loves the coffee grounds for this reason.
Many gardeners assume that coffee grounds are acidic, but this does not hold true experimentally. The pH of decomposing coffee grounds in these experiments ranged from 4.6 (mildly acidic) to 8.4 (somewhat alkaline). The pH also changes over time and you should not assume that it will always be acidic. Research indicates that the pH of the grounds tends towards neutral as it decomposes.

Old coffee grounds have been found by farmers to produce some of the biggest melons, tomatoes and carrots. Coffee grounds add minerals, vitamins and nitrogen to the soil so that the vegetables are stockier and less prone to insect infestation.

The earthworms and worms of all types love the grounds as they provide food for them. The worms derive nutrition from the grounds and this increases their production which means aeration of the soil, by breaking it up, mixing in air, and their worm droppings. This in turn improves the soil structure, water movement, nutrients in the soil, and ultimately increases the plant growth. 

As for soil-borne diseases, coffee grounds do appear to suppress some common fungal rots and wilts (Fusarium, Pythium, and Sclerotinia) as well as some bacterial pathogens (E. coli and Staphylococcus).

Gradually give your plants a dose of coffee grounds. Start out by giving your plants just a small amount of coffee grounds. Try just a teaspoon around the base of the plant, not next to its stem, but under its drip line and gently scratch in into the surface of the soil, no more than 1 inch deep. Wait a week and then try it again. After a couple of weeks increase or decrease the amount or don’t give any depending upon what your plant is doing.

Step 5: Coffee Tea?

That is correct. You can make coffee tea to use as liquid fertilizer.

Make coffee ground “tea.” Add two cups of used coffee grounds to a five-gallon bucket of water. Let the “tea” steep for a few hours or overnight. You can use this concoction as a liquid fertilizer for garden and container plants.

Step 6: Mulching With Coffee

A mulch is a layer of material applied to the surface of an area of soil. Its purpose is any or all of the following:-
to conserve moisture
to improve the fertility and health of the soil
to reduce weed growth
to enhance the visual appeal of the area

When you mulch with coffee grounds, don’t pile it on. That’s a sure-fire way to get moldy mulch. Since coffee grounds are finely textured and easily compacted, they can create a barrier to moisture and air movement, especially when applied in thick layers. A good half-inch thick layer atop your normal organic mulch in any one spot will do nicely. It will break down relatively quickly as worms and soil microbes go to work, and when it does you can add more.

Step 7: Pest Deterrent

Slugs hate coffee, cats hate coffee; it's even sometimes an effective olfactory-based repellent for picky deer. Some use the grounds as a deterrent for ants.

Ants are very particular about smells.  Sprinkle coffee grounds outdoors near garden beds you want to keep ants away from. The ants will turn around once they run into the smell of coffee. You can even sprinkle coffee grounds by doors to keep ants out of your house.

Use coffee grounds for slug and snail control. The slugs don’t like to cross the barrier of grounds as they are sharp enough to penetrate their bodies. Slugs are also sensitive to caffeine which can cause them to die. Note some areas such as European Union  have stated that using coffee grounds to deter slugs is illegal.

Kitty won’t think of your garden as a latrine anymore if you used coffee grounds around your plants. Double this effect by spread a pungent mixture of orange peels

Place a uniform unbroken ring of coffee grounds around the plants but at a good distance from their drip line. You must replace them after a rain.

Step 8: Other Uses for Coffee Grounds

Here are some other uses besides garden uses for recycling your coffee grounds.

-Before you clean the ashes out of your fireplace, sprinkle them with wet coffee grounds. They’ll be easier to remove, and the ash and dust won’t pollute the atmosphere of the room.

-Get rid of the smell of spoiled food after a freezer failure. Fill a couple of bowls with used or fresh coffee grounds and place them in the freezer overnight. For a flavoured-coffee scent, add a couple of drops of vanilla to the grounds.

-The secret ingredient in high-priced cellulite cream is caffeine. So save money and make your own. Mix 1/4 cup warm, used coffee grounds with 1 tablespoon of oil (olive, almond, walnut or massage oil will due). Stand on newspaper in the bathtub and apply the mixture over your cellulite zones. Then wrap yourself in plastic wrap and leave on for up to five minutes. Unwind the plastic wrap, then brush off the loose grounds. Remove the newspaper and take a warm shower using a exfoliating brush. Repeat twice a week.

-Soften and add shine to hair. When washing your hair, rub coffee grounds through wet hair and rinse. Coffee can also be used as a natural dye for lighter hair colors.

-Use coffee grounds as an exfoliate for skin. The course texture of ground coffee, works as a natural exfoliate. Add ground coffee to a creamy based soap, pat on skin, massage over skin, and rinse. The coffee grinds will help rub off dry dead skin and leave your skin feeling smoother.

-Coffee beans have another natural benefit for your skin. The caffeine  smooths and tighten your skin.

-  Rub whole coffee beans or grounds in your hands to get rid of tough smells like garlic and onion or to get rid of smells from chopping or cutting up pungent foods. Use this on your cutting boards as well. Note this is not an antibacterial soap, so you still need to wash up after.

-Make a used coffee grounds sachet. Fill old nylons or cheesecloth with dry used coffee grounds. Hang in closets to absorb odors.

-When you need an abrasive cleaner, coffee grounds can be used.  The course texture of the grounds make coffee a good abrasive cleaner. Use around the kitchen when wiping down countertops and such just be careful of any surfaces that might stain.

-Remove furniture scratches with wet coffee grounds. Clean off your piece of furniture then use a paintbrush dipped in brewed coffee grounds to fix the scratched area. The more times you do this, the darker the results will be.

-Dye fabric, paper or Easter eggs. Just like berries and flowers, coffee beans serve as a natural dye. Simply add used coffee grounds to warm water and let sit a bit to create a dye.

-After you give your dog a bath, rub coffee grounds through the coat of your pet. Coffee grounds are said to repel fleas. Just like ants, fleas hate the smell. Rub your dog down with a coffee mixture, and send those fleas packing.

-Keep bait worms alive by mixing coffee grounds into the soil before you add worms. Coffee grounds are a worms favorite food.
© 1996-2013, Reader's Digest Magazines Canada Limited - © 1996-2013, The Reader's Digest Association (Canada) ULC
© 2013 Homesessive

Step 9: Other Possible Benefits to Coffee

Coffee as a natural preservative:

Studies have shown that "roasted`` coffee has a natural antimicrobial effect on certain bacteria, namely Escherichisa coli ( E.coli) and Listeria innocua.

Coffee health benefits This does not use the grounds themselves but drinking the coffee does produce grounds:

-Studies suggest that enhanced coffee/caffeine intake during aging reduces risk of Alzheimer's disease (AD). Underscoring this premise, our studies in AD transgenic mice show that long-term caffeine administration protects against cognitive impairment. 

-Studies found that when people drank four to six cups of java per day, versus only two or fewer, their risk for Type 2 diabetes decreased by almost 30 percent. The number decreased by 35 percent when people drank more than six cups per day. The precise mechanism underlying the association between coffee and diabetes is not well understood.
Other studies found that a chemical called dicinnamoylquinide, which is present only after roasting, may reduced patients’ cravings for highly addictive substances like cocaine and heroine. 
Yet another study has found that caffeine causes an increase in the activity of the neurotransmitter dopamine. This in turn may have the ability to diminish feelings of depression.

Step 10: Storing Your Grounds

Many people do not have a compost bin, myself included. So what do we do with the grounds? Coffee grounds can be collected in containers, dried and stored for later use.  Your grounds can be stored in sealed containers. They can also be frozen for later use.

Thorough drying is important as damp coffee develops mold quickly. Remove them from the filters to speed up the drying process. Dry them by leaving them to dry in the sun, or bake them in the oven on low temp. Turn them over by mixing to ensure no damp areas remain.

I leave my coffee grounds on my window sill to dry. Care should be taken to ensure your grounds are fully dry before sealing as they can go moldy. This happens to me all the time as you can see in photo 2. 

Coffee tends to develop a green or blue-green fungus that looks like mold. Don’t worry - that’s good. The green fungus is really beneficial (Trichoderma species) while the blue-green one is reported to be moderately beneficial. In any case, moldy coffee is great to use directly in the garden, compost pile. I have read that these molds will not harm the coffee grounds and are not harmful to humans, but care should be taken while handling them. Molds are a natural process of decomposition. But if you still want to be certain, you can bake them in the oven before storage. Most mold die above temperatures of 175F.

Step 11: Conclusion

I hope this tutorial will inspire you to help the environment as well as your garden by recycling your coffee grounds. Enjoy your favorite coffee drink guilt free by reducing your carbon foot print.

Thank you for taking the time to read my tutorial :)


Below find a list of sites I used to collect information:
© 1996-2013 National Geographic
© · Erica Strauss / Northwest Edible Life
© 1996-2013 National Geographic
© City of Toronto 1998-2013
© 1996-2013, Reader's Digest Magazines Canada Limited - © 1996-2013, The Reader's Digest Association (Canada) ULC
© 2013 Homesessive
© Royal Society of Chemistry 2013
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National Center for Biotechnology Information, U.S. National Library of Medicine
8600 Rockville Pike, Bethesda MD, 20894 USA
© 2012 NYU Journalism

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