Updated 4/19/2012:
I am addicted to using coffee ground in my garden. Every week, I was a regular at the coffee ground bin at Starbucks. I felt like I am at Cheers and everyone knows my name. (Oh, come on, your remember Norm.)
Just to give you some background, my sickly roses miraculous perked up after a round of coffee grounds. And the love affair began. But, I began to worry that my new found obsession may not be the best idea for my plants. Sometimes a good thing can be too much. (How many of you saw Fatal Attraction?)
I was afraid I would have to quit cold turkey after my friend told me to be careful. She said I should not give the plant too much coffee grounds. What happens if she was right? (Gasp.) How much coffee should I be giving my plants?
Searching for the Coffee Grounds Guidelines
I started to dig (sorry about the pun) to find if there was a university study on the effects of coffee grounds on plants. At first blush, I only found articles written from gardeners or DIY’er reporting the same things I knew. No one seemed to answer the question of “how much.” The research was quite frustrating.
Gardens Alive Takes on Coffee Grounds and Plants
I stumbled upon an article on Gardens Alive answering a question from someone in New Jersey asking the effects of coffee grounds on plants. (And no, this wasn’t my question.)
Gardens Alive had coffee grounds tested by Will Brinton, founder and Director of the Wood’s End Research Laboratory in Maine. He found the grounds were too acidic, even for acidic loving plants. He also cautioned the grounds should not be added to the soil in raw form. However, he did like them for compost.
“Will liked my [Garden’s Alive] suggestion of four parts shredded leaves to one part grounds by weight, but adds that even having grounds make up 10% of a pile of otherwise shredded leaves would create great compost.”
Well, that article definitely was a damper for me. (Okay, it was a kill joy.) It seemed that I can only use the grounds for composting.
To add to the confusion, another gardening article I read called coffee grounds “brown matter.” Boy was I confused. So, if I followed Gardens Alive’s advice to add leaves to my coffee grounds, would I have to supplement with more “green” material for my compost?
This can’t be this complicated.
Rodale Institutes’ Respond to the Coffee Grounds Dilemma
I reached out for Rodale Institute since it was more likely they would have an answer for me. (If the name, Rodale Institute, sounds familiar to you, it is because many of you may know the name through the magazine, Organic Gardening, one of my favorite gardening magazines.)
Luckily I connected with Dr. Paul Hepperly, the research and training manager at the Institute, who is a well known authority in organic agriculture. Surely, he would know. (Fingers crossed.) He explained that once the coffee grounds are added to the soil, they start to decompose, and in turn, their acidity neutralizes. Ultimately, they are only adding nitrogen to the soil.
Best Practices for the Use of Coffee Grounds
His suggestion was to side dress the plant with no more than one inch at a time. He further caution to not add more grounds until the original grounds had decomposed. Coffee grounds are solely a soil amendment and not a fertilizer.
He further explained that soil should have an organic matter of five to eight percent. At some point, there is a diminishing return if you keep adding coffee grounds, and you soil has already reached the eight percent threshold of organic material. It will not hurt the soil, but may not help much at that point. It is best to take a soil sample during the year to see what your soil needs.
As for compost, he suggested one volume green material to three volumes of brown. Coffee grounds are viewed as “green” material. (Whew. I was relieved that this matter was settled.)
What about using coffee grounds for composting? Read on for my final segment on using coffee grounds for compost.
Join the Conversation:
- Have you used coffee grounds in your garden? If so, what was the result?
- Have you put coffee grounds in your composter? If so, what was the result?
- Do you think the grounds are too acidic and don’t use the grounds in your garden?
- Do you use coffee grounds for any other use such as getting rid of cellulite as espoused in DIY Maven’s post on Curbly.com?
- What common household item do you use in your garden?
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Excellent Blog! I didn’t know about coffee grounds! How about that and go “Starbucks” for being ready for you! Great blog and information!
Thanks, Melanie. Readers check out Melanie’s blog. Here’s how she describes her blog, http://thriftyme.blogspot.com/
“Be Thrifty in CREATIVE ways with my Blog!
I love saving money or finding a way NOT to WASTE!I try to figure out a way to use, sell or creatively not toss items!”
A woman and mom after my own heart. Melanie, if you find a great tip on how to save money and be creative, please contact me so I can put it on Green Talk. Welcome to the community and visit again.
Before I forget, readers, you could probably ask any coffee house or restaurant to save the coffee grounds for you and do the same thing I did with the grounds. Even use your own too!
Thank you Green Talk! I do love your blog and I will be looking for ideas for my household on your site! I truly love to find ways to save money, and the green way interests me most! I find myself speaking “green” to my students (I am an Art Teacher to Elementary kids). And I am sure you know, Art of many types can easily recycle so much, creating masterpieces rather than Landfill Trash/Waste! I am huge on that! I am always like, “think before you toss kids” Can Mrs. R use that? I ALWAYS find a use for nearly everything that a lot of people throw away. The Art Room is a great place for everyone to donate and know that it will go to good use. Items don’t have to “create” something necessarily…it could be a brush container, paint holder, storage, and of course the masterpieces as well! I could go on and on! LOL
Great blog, I will frequent! Thank you for the compliments!
Melanie-If you come up with some ideas for reusing items that would ordinarily go in the trash, I have started a category on Green Talk called Readers’ Reuse Tips. I am sure my readers would really enjoy any tips you have. Seems like you would have a lot from your art classes. Anna
So many people do not realize they are being “green” when they reuse items. All it takes is a little creativity!
What a great idea! I’m going to go do right now.
I’ve been using coffee grounds in my compost for quite awhile. I think I first read about it in a Peace Corps manual some years ago… then again it could have been a Rodale book the Peace Corps had. Anyway it’s good stuff in moderation. I have discovered that I cannot put it in my compost pile, not because it doesn’t work, but because my dogs like to eat it… go figure.
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Enjoyed this article and referenced it and your sources in my own article about coffee in the garden. Just one problem, I couldn’t find your name to give credit in the narrative, so I just linked to this – Maybe that’s what you prefer.
Margaret Woda’s last blog post..A Little Coffee for Your Garden?
Thanks so much for the mention on your site. I loved doing that article. As for starbucks, I am just waiting for them to start it up again for the spring. You should have seen my compost with the worms. I swear they did not get any sleep! My name by the way is Anna Hackman.
What an outstanding article! I’ve been loving your site here (just found in a couple months ago), and stumbled on this post today. Talk about thorough coverage of a topic! Wow.
I haven’t tried using them directly in the garden, but I have found that coffee grounds are an excellent addition to a worm composting system. That being said – moderation is definitely the key. Back when I was young and foolish I remember adding a lot at once, and ended up making my bins go sour pretty quickly.
If you see a huge abundance of tiny white worms in the immediate vicinity of the grounds these are likely white worms (aka pot worms) – while harmless in a worm composting system, they generally are indicative of acidic conditions (not necessarily a bad thing since composting worms are highly tolerant of acidic conditions).
I like mixing in egg shells (the more ground up the better) with my worm bin additions, since they can help to keep things balanced.
B.
I used about1/3 used Starbucks espresso “pucks” 1/3 worm castings and 1/3 native soil (southern Cal – clayey, high mineral, high water retention) for virtually everything I planted in my “garden of Eden”, including hydrangeas, begonias, azaleas, roses aplenty, and more. Everything grows like gang busters!
I’ve read that the acid converts to nitrogen and only about 2% of the nitrogen is continusously available because it breaks down so slowly. IOW-it’s hardly possible to overdo it. And since chemical fertilizers KILL the trillions of healthy microbes, fungi and bacteria in healthy soil, not to mention what it does to your butterflies and birds and ground water, coffee grounds and compost makes beautiful sense!
coffee grounds on your soil also tends to keep cats away from digging there, but only for a few days till the smell wears off, then you can go again.
Nice post. I never knew this. I do like to feed my tomato plants with gone flat beer – now I know about coffee too.
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I have a worm bin. I would say about 70% of what i compost is coffee grounds [worms LOVE it] 20% is crushed egg shells [glad to hear that may help balance acidity] & 10% plant material. Then i add shredded paper or cardboard to balance the green. I also recently added a big batch of spent grains from home-brewing [and worms loved that] I say ‘love’ when i see massive increase in their #’s. If food good they mate & reproduce more than if no food or bad food..[ i assume. ]
ALso, i drink beer & usually get it in re0useable growlers, so i don’t have to recycle bottles all the time- i rinse out & refill. When i rinse, i like to pour the first 2 fillings onto plant helping water them… seems to be ok. I figure it might help fungi growth?
I saw a garden tv show and a lady was explaining vermiculture. The worms loved the coffee grounds from their company coffee brewer. Maybe those worms in”Men In Black” had something going. I do , in early spring , spread some around my roses and cranberry plants. They are fine.Good luck to you and—bottoms up!
I have a ton of coffee around my roses this year but the beetles are just laughing at my coffee grounds. They are eatting my roses alive. Urg!
Wasting, good idea about stale beer. You can also use it as traps for slugs too. Slugs don’t care if it is good beer or bad beer. They like the sugar. Put it a container near your plants. I hate slugs although I know they serve a purpose (somehow.) Check out my slug post on the site and you will see why I hate them so much. Anna
Great idea. I wonder if it will work around catnip as well? Cats love that plant. Anna
Cora, Wow coffee and worm castings. The plants must love it. I guess this is like eating chocolate all day for us! Anna
Compost Guy,
I throw my egg shells in there too. I hate to admit this but I am a compost flunkee since I have been processing compost for about 2 year. I just keep throwing stuff in the composter (brown and green) and it goes down and I throw more in. My problem is I don’t keep it wet enough.
Question for you. I have a terrible fly problem I think because I get delivered 20 yard of compost and I don’t move it quickly as well as big size garden. Do you think I am creating the problem? (ie flies breeding in my garden?) Anna
By the way my friendly worm population loves, yes loves,the slug beer traps. They don’t drown in it but stretch from their holes to party.
So is this a good idea to have beer traps with worms and the slugs? Hey, worm can have a good time too. Anna
hi Green Talk,
Man, you write long posts!
But thanks. I found you on google. I’m wondering about using coffee grounds in my garden instead of tossing them. I’m still not sure, but I feel I know a lot more! Steve Booth
PS. I’ve always wondered about the Starbucks bags. I’m surprised there’s not more info out there, but it seems like you found all that there is.
Steve, I do write post because I want my readers to be able to make an informed decision about whatever I am writing about.
All you have to do is get some coffee grounds and sprinkle them around your plants or put it in the compost. It’s easy and smells great. Anna
Grounds are great for roses,compost and your worm bin.I have used grounds for a couple of years now and my roses are beautiful.I moved them a few weeks ago and added grounds to the soil as I replanted them.All of the plants are thriving……they are in a much better spot also.Roses also love banana peels.I recently read that you should dry them first,but I’m not sure why.I dry some and bury some fresh.
I compost alot of stuff and believe that everyone should at least compost as much of their food scraps as possible.Sometimes,I just dig a small hole in a flower bed and bury a small amount of food scraps.It will rot and help amend the soil.
Recycle,reduce and reuse.Three words that should be part of everyone’s vocabulary.We must do even more then we have before to slow down the absurd amount of waste in the world.
I just discovered your blog and have added it to my favs.Keep up the good work.
Roxanne, I have heard about banana peels and roses. I will be burying a few come this summer. Have you heard about egg shells and tomatoes? Anna
Coffee grounds have had a healing effect on my rose bush and they seem to repel diseases and pests: I can’t believe the difference they made to my disease-stressed and dying rose bush. The leaves are perfect as are the blooms. Coffee grounds must be the secret to growing exhibition and/or competition roses.
Re banana peels: A gardener friend of mine recommended them for repelling ants. She used to wrap the peels around the stems. I never tried it, so I personally don’t know if it works.
Halelani, I glad the grounds helped you with your roses! Anna
Great blog post! I love learning about this online as gardening/landscaping are not only hobbies of mine but I actually do a little bit of work like that during the summer months as a second job. I appreciate your content in your blog and wish that you would keep up the good work
I’ve been putting coffee grounds into a little compost pile I’m working on in my garden for the past month or so. I have to say it works remarkably well to add in other garden waste, dead plant material and organic material to the mix. My soil has gone from very clay like to moist and workable very fast. I’m even seeing tons of beneficial earth worms now.
Pat, worms love coffee grounds! Anna
I’ve also been using coffee grounds for quite awhile and find they do attract the worms which is a good thing. I also use, on everything as well as my roses, a product called “Soilsoup” an organic aerobic compost tea made by greenorganics.biz . Not only does it work well for the soil (microbial activity) but if you use it to spray the foliage it helps with the rust and other assorted fungus problems you may have.
Viki, that is good to know since my roses always get rust. I wonder if it takes away powdery mildew too? Anna
Can you use coffee grinds with house plants as well???
I have an infestation of meally bugs on one of my plants. Thank goodness it was separate from all the other plants I have.
I\’m just wondering if I could mix some coffee grinds in with fresh soil (how much should I use). I read somewhere that it kills meally bugs as well.
Jen, I just put my grounds right on top of the soil and water. Some plants love it more than others. I have a spider plant that loves coffee grounds.
I don’t put a ton in the plant but just a smattering. Spread the wealth around your plants. I also throw it outside on my garden beds even when it is freezing out. Anna
Composting is like making a salad. Variety makes it better. I wasn’t aware of coffee ground use. Thanks for the tip, I’ll have to give it a try.
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Hi Anna ,
Just saw your posting on the beetles on your roses .
Epson salts works great for roses .1/2 to part water in a gardner sprayer will do the trick. Its a good fertlizer as well.
Good Luck
Rebecca, when do you apply the epson salt? While they are infested or before?
You apply befor infested once a week .And this will help stop infestation as well.
Epson salts is good for infestation and good for tender young plants and before infestation.
Great post! I drink WAY to much coffee good way to put my addiction to good use
Don’t tomatoes like acid soil? Would coffee ground rich compost be good for the tomato plants?
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I loved all the info on coffee grounds to increase acidity in soil. Thanks. It was very helpful..
I have been tossing my morning coffee AND grounds in my roses all season long for many, many years. I have an incredibly gorgeous bed of roses every year! An elderly friend told me of her “tossing her morning coffee and grounds out every morning, as her roses needed their morning coffee.” I have never since seen roses that could hold a candle to hers…except mine
I will continue with the “morning brew” for glorious roses!
This is new idea to enhance the growth of roses in garden. You brought a light on this & now many people including me will be benefited because of this. Thanks a lot.
thyroid problems
Found your post and all the responses while researching use of coffee grounds as a soil amendment. We garden in Florida where the soil is very alkaline. and struggle to acidify it.have been using sulfur compounds, but those are only temporary. Sounds like direct application of the grounds along with my other amendments will help a lot. We read elsewhere that coffee grounds deter if not kill off slugs which are a major pest here. Have been trying that for the last year and it seems to work. Thanks Starbucks for allowing us to haul away your trash. Bill
Bill, coffee may deter slugs but if you read my slug post, it was proven that it does not kill them. Heck, if it works for you, then use it. Anna
Just wanted to chime in about coffee grounds, if you are on the west coast you can also get grounds from Peet’s Coffee and Tea most days. If it isn’t in the silver bags out front, just ask a cashier about it. They should be able to give you some or make arrangements to do so.
I have a friend with a worm bin and he gives them coffee grounds and tea leaves, apparently they love it.
About coffee on roses, I’ve heard that one needs to more careful about using the grounds on potted roses. My roses love them.
Finally about compost, I’m a lazy composter (lazy in the sense of how I do it, not in doing it) and often simply have a hole or wired off area where I put kitchen and yard waste. It works, although it takes a bit longer.
Rachel, thanks for the suggestions. I happen to be an amazingly lazy composter…. Anna
I didnt know Starbucks did that. That is a really good idea too!
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Thanks for all the tips. I am using coffee grounds on the hydrangea.
Does anyone know if tea leaves work as well? Perhaps a mixture of both coffee and tea???
Great article! My parents are religious coffee drinkers, and I’ve been trying to convince them to do something with the grounds besides chuck them in the trash and let them go to waste. Thanks for taking the time to put all of this information together!
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Great article thank you, anything that gets the message out there about coffee grounds for the garden, the better.
I am running an initiative known as Ground to Ground to make better use of the tonnes of coffee grounds that are discarded each day, and have so far made use of 1.5 tonnes in my garden alone.
I have been tracking progress in my blog, and invite you all to stop by for some practicable tips and advice in getting into it. We can all make a difference, and with many of us, make many small differences.
Cheers,
Shane Genziuk
http://shanegenziuk.wordpress.com/2010/07/03/ground-to-ground/
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Great article! I’ve been researching composting because i want to do it this year. You’re article helped a lot.
I also came across 4 other really helpful options here http://healthnutnation.com/2010/10/05/4-composting-options-that-anyone-can-do/
Martin, I read the article. I actually have the same composter. Good luck in composting. It is so fun when you actually get compost. Anna
Hey Anna. Really love this blog. I use coffee grounds on my blackberry bushes and find them very effective!
Bed Bug, tell me what the coffee ground did for the blackberries. Thinking of using them on my blueberries this year. Anna
Collecting coffee grounds and using them in the garden works out so well for everyone. It seems to create healthy soil, which in turns helps plants become productive. And the worms like it too!
Shane´s last [type] ..Collecting Used Coffee Grounds UCG
Shane, the worms do absolutely adore coffee grounds. What other household item do you use for your soil? Anna
Mostly kitchen scraps and about 100 kilos per week from the local fruit and vegetable shop. I’m also getting about 250 kilos of lawn clippings and leaves a month from the local gardener. Between all that and the coffee grounds my soil is in very good health. Check out my site if you want to learn how any normal suburban block can do the same.
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Shane, how is your yield now? Anna
Substantially improved, and repeatable with every crop.
Shane´s last [type] ..pH of Soil from Coffee Grounds
Thanks for great post, I use coffee grounds during september to give my blueberries a bit of a boost, works like a charm!
Bad, why September? Blueberries are in July. Is this for next season?
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On coffee grounds, not sure if there is a bad side.I use them alot, when i say alot I mean alot. I cover all my beds with a couple of inches in the spring and then I cover that with wood mulch. Around my trees (apple,buckeye,hickory,oak,black walnut,pear,plum) I put about 4 inches thick and about a 20 inch diameter, they are all doing great.My compost bin is 16 foot by 8 foot and I put about 8 to 10 wheel barrows full in and about the same amount of horse manure and about 12 -14 wheel barrows full of fresh cut grass and lots (6-7 pick up loads 8 foot bed) of leaves along with kitchen scrapes along with hardwood ash from the fire place and I get enough egg shells from area restraunts to fill a five gallon buckets of finely chopped (almost dust, using a blender. And to top off the mix about 5 pounds of red worms. tasty. The only thing I dont put alot of grounds around is my roses,and they are the only thing that is not doing good.
where do you get so many grounds??? You must have the most amazing compost. Anna
starbucks I stop at 4 of them every night and if someone else has not got them then I do. I start in dec in the snow and backoff in may so that everyone else can get them. I sort the trash and filters out in the winter and throw away and save the filters for a worm box in the early spring , and I am putting them in my compost. I am thinking of putting in a mushroom bed in my woods and useing the filters for that also.
Bill, maybe it is you who keeps taking all my coffee grounds!
I hope not. where are you from lol….? one of my customers went to her local starbucks and they told her no, not till may. I cant understand why they would rather drag them to the dumpster than let some one else carry them out.
I am in NJ. Where are you? What do you do for a living?
I live in Ohio outside cleveland, I work for a company called lkq,we sell new and used car parts.
Love your thinking Bill!
Shane´s last [type] ..Collecting Used Coffee Grounds UCG
Took BedBugs advice and started sprinkling coffee grounds on my blackberry plant. I could swear that it is more effective than buying Amonium Sulphate from the nursery which is what I usually do!
hi everyone just to let you know you can throw coffee grounds straight around the plant just inoculate the area with mycorrhizae and it will fight and eat the mold bloom. Tested and proved in my vegatable garden and dahlia pots. But worms do love the stuff i think the caffine helps
Jonathan, sorry for being dumb, but what is “mycorrhizae?” Is mold bloom the awful stuff that blooms in mulch? Anna
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Thanks, Anna. Sorry I didn’t find this post sooner! I’ve only recently become aware of all the productive, sustainable ways we can use spent coffee grounds. Nice post
Sonailpgi, glad you found the site! Do you use coffee grounds now for your garden? Anna
Anna,
Though I don’t drink coffee very often, my gf does. And we compost everything
But some of the ideas I’ve found recently for viable uses of spent grounds have been enlightening — especially one about using them to make a flea dip. Clever.
I’ve heard that coffee grounds are effective with growing blueberries. Anyone care to comment on that?
Yes they are, and seem to go even better with Blueberries when added as a mulch with pine needles.
Shane, I have been trying to lower my PH on my blueberries, It is good to know about the pine mulch. Anna
Hey Shane, regarding your above comment to Natural Remedies.. you are so right! I set up my own little blueberry plant with mulched pine needles and it is very happy indeed! Haven’t tried the coffee grounds yet though…
This is a really new idea to enhance the growth of roses in garden. Very good post with useful information. I really appreciate the fact that you approach these topics from a stand point of knowledge and information. Please keep on posting.
This blog entry contained more than enough useful information. I want to thank you for your time and research. I just started my blog and I can tell that I have some learning to do. Keep up the great work!
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The following has worked absolute wonders.
Coffee grounds are only good for a limited time and purposes. The true and time tested way to really take advantage of coffee grounds are for worms. Worms absolutely will love you when you add coffee grounds and the worms. The worms will feed off that for ages and at the same time they will give oxygen, fertilizer to your yard, soil, etc.
In addition, you will not be wasting water because the water will sink into the roots of grass, plants, etc. without rolling off the top soil and bypassing the roots. The worms, through the use of coffee worms soften the soil and fertlize it at the same time.
Also, it help a huge amount if you do the following:
1. add leaves of the trees or grass into your soil, it will decompose greatly.
2. the paper board from egg cartons are awesome for retain moisture hence in the soil and for the worms.
3. till the soil, leaves, egg shells, lettuce for worms.
If you had not already gathered it by now the key are worms. All the rest is to feed and maintain “happy” worms. Worms do not sleep or rest. All they do is eat and pour out casting, fertilizer. This is a year round work-horse for your yard and garden.
I’ve used this method for ages and it works absolutely wonders. Now, the coffee grounds you can place in a large container with water let it sit there for a day or two and than spray that around. It’s more bang for your buck!
Continue to add worms, worms, worms, and more worms. You will not regret it. Research what I’ve expressed here and in the end you’ll come to the same conclusion. It’s also great for the environment.
I just found you! Thanks for the info. My mother’s roses have gone to the way side since she isn’t here to take care of them anymore. I got some coffee grounds and egg shells to see if I could bring them back to health. Now I know what to do. Thanks!
Ricia, let me know about her roses. I hope the coffee helps! Anna
Anna, “side dress the plant with no more than one inch at a time” is a quote from your article (loved it by the way…had been wondering since my brother brought me 2 bags of Starbucks grounds). I feel like a gomer for asking, but what does that mean? Please clarify? I don’t know if that means sprinkle an inch worth of grounds or and inch deep covering around the roses. I am guessing appx a cubic inch worth sprinkled around. I’m no gardener, so will you help me out here? duh
Suzanne, I typically just sprinkle it around. It isn’t that deep. So it wouldn’t be more than an 1 inch by 1 inch deep. I am glad you asked. Anna
I’m glad Suzanne asked that question b/c I was wondering the same thing myself!
Are you adding dry, unused coffee grounds or the “wet” ones leftover in the filter after brewing?
Caryn, I used the wet ones. Anna
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