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Can I add coffee grounds directly to my soil?
A friend of mine says that you can just toss coffee grounds out onto the soil as a way of composting but I am not so sure about this. I thought coffee was very acidic, will that not harm my plants? can they absorb the coffee through their roots?
Posted by: Stacey Cottrell
(1 point)
Posted: February 26, 2013
Answers
I've gotten bagsful of coffee grounds from coffee shops and added them to both soil and compost.
For soil, I found that the grounds will dry into a water-repellent crust if they are placed too thickly, say half an inch. To prevent that, just mix them with soil or cover them with mulch, and rake it all around a bit so that the grounds are not a separate layer.
For compost, many of the grounds I got were in lumps. I found that if I did not break down the lumps when I added them to compost, the lumps were still there a month or so later when it came time to sift the compost. So I placed a plastic nursery flat with small holes on the surface of the compost and crushed the lumps through the holes as I added them.
For soil, I found that the grounds will dry into a water-repellent crust if they are placed too thickly, say half an inch. To prevent that, just mix them with soil or cover them with mulch, and rake it all around a bit so that the grounds are not a separate layer.
For compost, many of the grounds I got were in lumps. I found that if I did not break down the lumps when I added them to compost, the lumps were still there a month or so later when it came time to sift the compost. So I placed a plastic nursery flat with small holes on the surface of the compost and crushed the lumps through the holes as I added them.
Posted by: Tanya in the Garden
(128 points)
Posted: April 4, 2013
Coffee grounds can most certainly be added to your compost and also directly to your soil. Instead of simply tossing them out though, you may wish to incorporate them a bit more thoroughly by digging them in.
Much to my amusement, I found an article from Sunset magazine where they actually sent a sample of Starbucks coffee grounds for a soil analysis and found that it was rich in nitrogen, phosphorous and potassium and all of these elements were present in a form that are easily taken up by your plants. You are also correct that coffee is acidic. Fortunately, by the time the grounds get to your soil, brewing in water has removed most of the acidity. The pH of the grounds tested was 6.2. You can read the article here:
http://www.sunset.com/garden/earth-fr...
Much to my amusement, I found an article from Sunset magazine where they actually sent a sample of Starbucks coffee grounds for a soil analysis and found that it was rich in nitrogen, phosphorous and potassium and all of these elements were present in a form that are easily taken up by your plants. You are also correct that coffee is acidic. Fortunately, by the time the grounds get to your soil, brewing in water has removed most of the acidity. The pH of the grounds tested was 6.2. You can read the article here:
http://www.sunset.com/garden/earth-fr...
Posted by: Lindsay McMenemy
(2 points)
Posted: February 27, 2013
I am merely an amateur gardener but I can tell you that after hearing the same thing you did I added coffee grounds several times to my tomatoes last year and they thrived just as much as they do every year. It's only anecdotal evidence as I lack the scientific knowledge of plants that Lindsay clearly has, but I hope it helps a bit :)
Posted by: Miriam Stein
(5 points)
Posted: March 3, 2013
Lindsay McMenemy commented,
the scientific knowledge is sometimes no substitute for getting out there and trying it! Thanks for sharing your experiences on PlantVillage Miriam
over 6 years ago.
David Hughes commented,
Have to completely agree here. We developed PlantVillage exactly for this reason. So everyone can chime in and share experience. You might be right, you might be wrong but until we can hear from your experience how can we (the crowd, plant growers) decide? So, it is all very valuable. The other thing is that very often new and interesting ways to grow food better comes from the kind of experimentation you did with your tomatoes last year. You are experiment which is what another plant villager, David Goodman does a lot https://www.plantvillage.com/posts/407
Thanks Miriam over 6 years ago.
Thanks Miriam over 6 years ago.
3 Comments