Coffee grinds for plants in your garden

Grounds For Your Garden

Coffee grounds make great compost additives, soil enhancers and pest deterrents. It's an inexpensive way to fertilize your garden, build a richer compost yield and promote worm activity.

As Compost and Worm Promoter

Spent coffee grinds make a great additive to a compost pile as they have a very high carbon to nitrogen level. Initially, the coffee will provide a good level of acidity and add a great texture to your compost, though over time it will not make the compost generally more acidic, as microbes in the composting process will turn the grinds from acidic to neutral pH levels. A common complement to coffee grinds in a compost pile is egg shells. Worms love coffee grounds too; adding coffee grounds to compost piles (or worm bins) will promote their activity as they feed on them. Because worms love to feed on coffee grounds, you can also toss the grounds in your garden soil to promote their activity in general areas.

 

Garden Soil Additive

As you would expect, coffee grinds are acidic with a pH level of about 4.0. So for plants that prefer more acidic soil content, like azaleas and tomatoes, coffee grounds make a great additive to the soil. Obviously, be careful to not add large concentrations of coffee grounds to plants that are highly sensitive to acidic levels. In general, mixing coffee grounds with garden soil for a topping layer in gardens is an excellent way to add organic matter to your fertilizer mix. Mixing the coffee grounds with soil allows for a diffused, even concentration as well as prevents mold which may occur if coffee grounds are spread as clumps. Other plants that like the acidic taste of coffee grinds include: hydrangeas, blueberries and rhododendrons.  Homemade organic fertilizers are rewarding and satisfying - adding coffee grinds to the mix helps you to control the pH levels.


Slug control

Your average household spent-coffee grounds contains roughly .05% concentration of caffeine. Though this is not enough to kill slugs (i have read that you need about a 2-3% caffeine concentration to achieve this effect), it is a great slug and snail deterrent. Sprinkle the grounds around the tender plants and veggies that you want to discourage slugs from addressing.

Managing and Collecting

Keeping wet, spent coffee grounds in a can or a bag can turn into a moldy smelly mess, so it is good practice to deploy your grinds on a frequent (a few times a week, if not daily) basis.

If you do not have a lot of coffee grounds at home, the office is a great place to collect them; place an empty coffee can with a sign on it next to the coffee maker at work and soon you will have your fill of this lovely garden additive. Local cafes usually have a spent coffee grounds program; Starbucks' Grounds For Your Garden program is a good example. So if you want bulk, go ask your local coffee shop! (you'd be surprised at how many folks have Starbucks coffee grinds in their flower beds!)

Here are some other suggestions for managing your coffee grounds project:

  • Go ahead and toss your coffee filters into the mix along with the spent grinds. All the filters that I have ever come across are biodegradable and are fine to add to a compost pile (and makes it easier and more convenient to recycle your grinds).
  • Mix your grinds with equal amount of organic potting soil and add water to create a fast acting liquid fertilizer (in a big five-gallon bucket mix 1 lbs coffee grounds with 1lbs soil and the balance with water).
  • Ring your plants with coffee grounds just before watering them or before it starts to rain; this will provide a great slow-release source of nitrogen. As mentioned above, this also serves as a great slug and pest deterrent.


example of coffee grinds in the garden

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Comments 44 comments

moonlake profile image

moonlake 7 years ago from America

I use to do this for my garden all the time and have forgotten to do it. Will have to start using those grounds.

Good hub.


Mardi profile image

Mardi 7 years ago from Western Canada and Texas

Thanks, I knew they worked but didn't understand how much coffee grounds could help!


mikethegardener profile image

mikethegardener 7 years ago from New Jersey

add coffee grounds to your vermicompost pile also....worms love the stuff and vermicompost is far better for your soil then straight coffee grounds....great article!


Peggy W profile image

Peggy W 7 years ago from Houston, Texas

We are adding them to our new compost bin. I had no idea that they could repel snails and slugs. Great news as we have plenty of them in Houston. Thanks for the information.


Byronthegardener 6 years ago

I have always been getting some from parents and friends. I recently found out about the Starbucks grinds for gardens program and have been picking up a 20 pound bag every couple of days. During the fall, I started to top dress the lawn, and it greened up as if I put down turf builder. Hope no one else finds out ;-)


Dondro Gardens 6 years ago

Love doing the natural in the yard and garden.

Thank you for the tips!

Donna


Allison 6 years ago

They are also a very good (and harmless) deterrent to cats who will use your freshly dug garden as a toilet


Mike Chronos 6 years ago

I love the idea of using grounds in the garden. I especially enjoyed Allison's comment about coffee repelling cats who enjoy using the garden as an outdoor litterbox. I'm going to add a bit to my garden this year. Nice hub.


globalcoffeegrind profile image

globalcoffeegrind 6 years ago

I've heard about recycling coffee grinds in gardens from Starbucks, but this is the first time I hear about the slug thing. Cool! Thanks for sharing.


myawn profile image

myawn 6 years ago from Florida

I knew they worked but didn't know why. My mom told me about them she put them around her roses.


GreenGoodsGuide profile image

GreenGoodsGuide 6 years ago from Lehigh Valley PA

When I add coffee grounds around my hydrangea bushes the blooms turn from pink to blue! Less coffee grounds and they're in-between, a pale lavender hue.

Beer cup traps also work for slugs. Bury the cup so that only around a half inch is above ground, and fill it partway with beer. Empty periodically, and yes, it will contain formerly drunk and now dead slugs.


toothache pain relief 6 years ago

there was a time when my mother n i used to do this, however with time things changed. Anyway, I am gonna start doing this again. Thanks


OrganicMay 6 years ago

Hhmmm, not sure about it, i tried and it hasn't worked very well as a slug repellent atleast. I think caffeine is the secret ingredient, a few years back there was something in the news about caffeine killing and repulsing snails and slugs. Brewed coffee has most of the caffeine taken out doesn't it?

I absolutely hate and do not use chemicals on the garden, anyone have any real experience of deterring slugs with coffee?

Found this link about the science behind it, also found coffee only has 0.8% caffeine, not enough I Guess..


Nikko 6 years ago

I did a 5 minute experiment early this morning. I made a ring of coffee grounds on the soil in my veggie patch.

Then I caught three slugs and two snails and placed them inside the ring. Without exception and without hesitation, all five of the critters marched straight over the grounds and continued on their merry way until my boot stopped them permanently.

I suppose I could design a more definitive experiment but I don't think I need to.

Please stop spreading the coffee grounds, snail and slug deterrent myth. That's all it is.


Lady Guinevere profile image

Lady Guinevere 6 years ago from West Virginia

These are great ideas and suggestions. Thanks for the Hub!! I didn't know worms like the grounds. I will definitely put them in my worm bins and around my Tomatoes. I voted it up and useful.

@Nikko, try the pie pan full of beer. It DOES work.


Ren Chin profile image

Ren Chin 6 years ago Author

thanks guinevere. glad you like the hub.


elise 6 years ago

This is a killer article. Thanks for all the info. I learned so much more than I knew. I had no idea coffee filters were something I could put in with compost. San Francisco is really pushing composting. The building we live in now has compost bins and I hear they will be mandating it citywide soon. We have already started but there is always more to learn. Ours is full of coffee grinds!


Shane 6 years ago

Thanks for the article. I also have an interest in coffee grounds for the garden and have started an initiative called Ground to Ground to get more people into it.

My blog has become dedicated to the topic of coffee grounds in the garden, and you are welcome to share in the growing body of knowledge I am assembling there.

http://shanegenziuk.wordpress.com/2010/07/03/groun...


how to get rid of eczema 6 years ago

never knew all of this stuff about coffee. All I knew was that I like drinking it.. Guess there is a lot to learn.


best way to lose belly fat 6 years ago

nice to know coffee has a lot more uses than just drinking it!


Terrylee5151 profile image

Terrylee5151 6 years ago from Pennsylvania

I have been doing this. I can remember as a kid that my Mom and Dad threw their coffee grounds in the garden.

I am your new follower


MyWebs profile image

MyWebs 5 years ago from Sheridan, WY

Great hub. I have a quick question. Would it hurt the compost if it was mostly full of coffee grounds, like is it possible to have too much in your compost?

I drink a lot of coffee but I have not been composting it all because I thought too much of it might not be so good. My compost consists of practically all greens. After reading a few of these articles I see I need to add some more browns to it.


Ren Chin profile image

Ren Chin 5 years ago Author

good question MyWebs. A higher concentration of coffee grounds in your compost mix will accelerate the process a bit, and definitely will increase the acidity level of the compost. SO if you plan to use the compost with plants that like that more acidic pH level, then it is ok to have a mostly coffee ground mix...obviously, if you are going to use the compost for general purpose, then you want to be careful not to have the coffee grounds exceed 30% of the compost mix.


compellingcarl profile image

compellingcarl 5 years ago from small town upstate New York

A large part of my compost pile is composed of coffee grinds and I have always had a feeling that they were very beneficial to the integrity of that compost, but in this hub you spelled it out for me in a wonderful way!


Chris 5 years ago

I've been using coffee grounds for a couple of months on my plants. I haven't really noticed any difference, although I have to admit the plants smell really good for a couple of days.

Now I just put the grounds in my worm bin. It's just the vermicompost that I'll spread over my plants.


gs 5 years ago

a snail and slug problem is really a lack of birds problem, try diatomaceous earth


Writing_Wine profile image

Writing_Wine 5 years ago from San Francisco Bay Area

Did you know that some starbucks actually give their used coffee grounds away for exactly this purpose? Very cool hub. Oh and to your readers who are having snail/slug problems - try putting smashed egg shells in and around your plants.


Ren Chin profile image

Ren Chin 5 years ago Author

Thanks @writing_wine, and yes! that's a good point - both Starbucks and Peet's coffee often will have used coffee grounds ready to give away for their gardening customers.


D Gardener 5 years ago

Can i use the coffee grinds for a grapes plant?


Surfraz profile image

Surfraz 5 years ago from India

this is very useful. Here in India people use coffee grinds and used tea powder too but i had a very bad experience as lot of ants came in for the taste of tea and milk in it.could you tell me what ph leave will happen to my soil if i use used tea powder to it.


s.carver profile image

s.carver 5 years ago from San Francisco

I have heard coffee grinds are very good to use for rhododendrons and azaleas, too, which like a lot of acid in the soil. I plan to give it a try! Thanks.


Ren Chin profile image

Ren Chin 5 years ago Author

thanks s.carver. Yes, add it to hydrangeas and watch its effect on the color!


Annette 5 years ago

Good article, also remember to keep the banana peels. I dig them in with the dirt around my roses and the roses love them.


MaMaKat 5 years ago

I go to groups to talk about the "new" "old" ways of gardening, and I always start with "Plant a rose, plant a banana" It gets a lot of laughs, but starts the group out thinking of the simple ways to enhance your soil.


Brian 5 years ago

How does Fig Ivy react to coffee grinds ?


Dolores Monet profile image

Dolores Monet 4 years ago from East Coast, United States

It's great to have something to do with those old coffee grounds instead of just throwing them away. I've been mixing some into the soil by my hydrangeas in order to make the flowers more blue. Hope it works! I love blue hydrangeas and mine are too wishy washy colored.


sgbrown profile image

sgbrown 4 years ago from Southern Oklahoma

Really great advise! I have been mixing my coffee grounds with my soil for some time now. It does help break up the soil, add nutrients and I have no slugs or snails. Voted up, useful and sharing! Have a great day! :)


RTalloni profile image

RTalloni 4 years ago from the short journey

Thanks for sharing interesting info on using coffee grounds in the garden. Have been putting them into our compost bin for years. I've been using coffee grounds on a small hydrangea for over a year now. The first spring the blooms were a pretty pink. This year I am enjoying an amazing bush of bright pink hydrangea blooms. Thanks to the coffee it is making quite a show out there with its blue sisters.


TrahnTheMan profile image

TrahnTheMan 4 years ago from Asia, Oceania & between

Wow! Timeless hub! Thanks for the tips. I've heard people talk of using coffee grinds but never got the science on it. Great info in here.


Riviera Rose profile image

Riviera Rose 3 years ago from South of France

This is something entirely new to me, and I can't believe that for years I've been tossing coffee grains out into the messy bit of my garden while totally ignorning the acid-loving plants I have just outside the kitchen! From now on I'll spoon them carefully into the pots and watch my camellias and azaleas thrive! Great hub, thanks.


Futamarka 3 years ago

КАКИХ ПОДВОХОВ ПУДРЫ СТОИТ ОПАСАТЬСЯ? Лучше не экспериментировать с цветными пудрами (если, конечно, вы не собираетесь на карнавал). Сиреневые, зеленые, ярко-розовые и желто-оранжевые оттенки используются профессиональными визажистами для созавивания специального эффекта и требуют особого мастерства в обращении. Осторожно следует обращаться и с пудрой, содержащей золотые и серебряные блестки, нельзя наносить ее на середину лица. Глянец может быть уместен на висках, скулах, в области декольте и на руках, причем только в вечернем освещении. Особую внимательность нужно проявить и при использовании темной пудры. Не рекомендуется припудривать ею область вокруг глаз, где могут быть гусиные лапки.


Mom Thoughts 3 years ago

I have been ringing my tomato plants with coffee grounds and it is good to know I am actually doing something beneficial! I heard about coffee grounds helping plants from a friend and had been skeptical but trying it. I will definitely continue.


annieangel1 profile image

annieangel1 22 months ago from Yorkshire, England

I used a mix of coffee grounds and compost to grow mushrooms - great result


gepeTooRs 8 months ago

I’d like to write like this too

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