A Dirty Colloquy – Using Coffee Grounds in a Garden
So grab yourself a cup of coffee and let’s talk some dirt!
Many well seasoned gardeners have tested using coffee grounds in a garden and have discovered a few, rather positive benefits. From balancing the pH levels and possibly running off the pests, to other important benefits that should also be considered.
Some of the bigger benefits, and important ones include:
- Offering the extra bit of protection for the environment. Pesticides and commercial fertilizers are harmful and leave soil unhealthy while empty fertilizer and pesticide containers go from the garden into the garbage. This means not only have those products went into the garden soil, but the landfill soil as well. Think about the future of that soil.
- Also, not killing or harming the insects and animal life. With a naturally built-in ecosystem, hurting the insects could harm this complex network of life. For garden health it’s best to use organic options that will help redirect them by using the companion planting method. Most insects are good for one plant or another.
- Last, is being economically friendly. If the estimated 700 million cups of coffee are being brewed each day in the US alone, then Americans are using tons of coffee grounds. This not only makes sense economically – it literally makes CENTS!
When you make your morning coffee, stop throwing those grounds into the trash and start putting them in a nice, clean bucket or in your compost bin along with the filters.
Saving your coffee grounds is an easy, free, and organic compost material that nourishes your soil.
So, Let’s Get Diggin’!
Digging up some more dirt, I realized that the majority of people agree that used coffee grounds are neutral in pH, but some want to continue claiming they’re too acidic.
According to only one of the many studies out there, Oregon State University’s Extension Service produced a nice, to-the-point, fact sheet which dismisses the idea that coffee grounds are too acidic. The “fact” is that the acid in fresh coffee grounds are natural and water-soluble, which means that once brewed, this little troublemaker (acid) leaves the grounds and goes right into your cup .
However, not everything in a coffee bean actually makes it into your cup of jo. Along with other ingredients that remain in the coffee grounds is the aroma producing oils, and even small amounts of caffeine.
Comparing information with OSU’s Extension Service fact sheet, the Wisconsin State University Extension states:
Nitrogen-rich proteins needed for seed germination and growth comprise over 10 percent of the content in coffee grounds (Tokimoto et al. 2005). Since coffee is extracted in water, most of the hydrophobic compounds, including oils, lipids, triglycerides, and fatty acids remain in the grounds, as do insoluble carbohydrates like cellulose.
So, basically once coffee is brewed and has undergone the process, the acidic level will have decreased, leaving the grounds at a more neutral pH.
“More coffee please? – The dirt’s getting good!
Composting your leftovers…
Coffee grounds are a super source of nitrogen for your compost. If you’re a gardener, you probably already use your coffee grounds as a “must-have” in your compost mix.
You can begin composting, by first collecting coffee grounds from your morning coffee. You can also check with your local café and restaurants to see if they can save some as well. Start putting them into a clean 5 gallon bucket, or a nice 30+ gallon trash container. Park it next to your compost pile for a later, quick, and easy access.
To compost your coffee grounds, start layering your elements in equal parts, using a third of each of the following – leaves, fresh grass clippings, and used coffee grounds. You can also add your coffee filters, shredded newspaper, and other paper items that you might have laying around, as they’re all a great source of carbon.
By having your mixture outside; sitting for a period of time (several months), it allows for bacteria and fungi to break down the different chemical components that are nitrogen-rich – like proteins and caffeine.
By the end of the compost process, the carbon-to-nitrogen ratio you should look for, ideally, is 10:1.
Some people might think that during this process, their coffee grounds are going bad. Don’t worry – they’re not! Coffee grounds do not go bad, according to the “fact sheet” from OSUES.
The earthworm conundrum…
In general, a friend of the compost is the earthworm.
Although it has been a speculation that coffee grounds attract the earthworm, there is no science-based information that supports the idea that the coffee grounds actually benefits them. However, it is noted that earthworms, as well as other bio-consumers of the ground, do use coffee grounds as a source of food.
Also, because earthworms pull the coffee grounds deep into the dirt, that may be what accounts for the noted improvements in the soil structure, after the coffee grounds were applied.
Black Gold! – I’m feeling rich :o)
This rich, dark compost can be used either by tilling or working it into the soil, or simply by using it as a nutrient-providing mulch. Either way, through studies and experiments, the results have shown positive effects in the soil.
Like all good mulch, using coffee grounds in a garden help maintain the soil temperature.
When using as a mulch, only apply about one half inch of coffee grounds; topping it with about 3-4 inches of wood chips. This will prevent the coffee grounds from compacting or drying out. Dry, compacted grounds will stop the water and nutrients from getting to the plants.
In the garden
There is much documented evidence that indicates, you can combine approximately 30% coffee grounds with any type of mineral soil to improve it’s structure. With that being said, the better way to get the job done is by working the grounds into the soil with a tiller or cultivator. To get the coffee grounds thoroughly mixed in, you will need to till approximately 6 to 8 inches deep into the soil.
Combining the coffee ground compost into your garden, will help improve the phosphorous and potassium, as well as the magnesium, calcium, and copper minerals.
This 9 Step Guide can help you get started.
Plants and Pests
Plants like coffee grounds. Especially tomatoes and roses. But those aren’t the only ones that enjoy getting their share of delisciousness. Others include hydrangeas, azaleas, and even watermelons! Yes, watermelons. Watermelons love the hot rich soil. Actually, the hotter the soil, the better the melons.
Back in her elementary school days, my niece decided she wanted to grow watermelons outside her back door. A few weeks after planting them, she decided to start using coffee grounds, and began working them into the soil, around the plants, with her fingers. When it came time to harvest, they were so delicious – super sweet, and very juicy.
Also, one of the locals in my home town uses used coffee grounds in his garden. He agrees that they are beneficial in growing his vegetables and because he gets them from local coffee shops, they’re a great way to recycle.
It is important to know also, you don’t apply coffee grounds in areas where you are growing plants from seeds. This can cause reduced seed germination and in some cases, reduced plant growth.
Last, a pest can be your pal. If you plant, using a companion planting method, you will see results of pests hard at work – in a good way! Among everything, there is good and bad. As for the garden pests, that is equally true.
To sum things up, whether tilled into the soil or used as a mulch material, coffee grounds have been proven to have a positive effect on garden soil. Don’t waste a chance to feed your plants!
Please share this article with family and friend or anyone you feel might benefit! Feel free to leave a comment, sharing your thoughts about using coffee grounds in a garden.
Thanks so much. – Paula