Need Coffee Grounds for your Compost?

Kidbruv

Well-Known Member
I just discovered on another gardening forum that Starbucks has a "Grounds for your Garden" program where they give out complimentary 5lb bags of coffee grounds upon request.

I just called up a Starbucks that I will be passing by on my way home today and asked about it. A really nice lady named Madeleine told me "yeah sure! I'll make sure we put some together for you and will have it for you to pick up" . That easy.

So I'll report back when I get it a bit later, but it seems I may have just found a cheaper than cheap and easy source for the N content in my compost.

Anyone else been making use of this?
 

indican3

Well-Known Member
I remember seeing said bags at a local Starbucks, probably 2 years ago and was pretty surprised they were free, wasn't interested in gardening at the time but thought it was cool.

I don't think you need much though, 5lbs would really increase the amount of N in mixture, maybe too much for a single bin. It's a good deal nonetheless, I make enough coffee myself that I could probably self sustain my composting needs though :)
 

Kidbruv

Well-Known Member
I was thinking the same thing. Too much coffee grounds might skew the ratio too far toward the N side of things. Nevertheless, carbon materials are so easy to come by that it's a nice problem to have.

So when I got to the Starbucks and spoke to 'Elaine' who was the one that would be holding it for me, she asked if I minded that there would be paper filters in with the grounds. I said not at all since they will break down. She brings out a massive bag for me that had somewhere between 10 and 20 lbs of grounds in it! I asked her out of curiosity if they give away a lot of grounds or if most get thrown out. She tells me that this was the first she'd ever heard of the program and that they throw out all their grounds. And she was a supervisor.

When I got home and opened it up, not only were there filters, but also lots of foil-type coffee packages in it. I picked them out no problem, but it tells me that they don't even put their grounds in a green bin for municipal composting. What a waste. Literally.

So anyways I put the whole big bag full into my two composers. I added some wood ash and sawdust to compensate for all the N-rich grounds. Once I get leaves in there, I think it's gonna be great.

Here's what I got...IMG_20160820_1736535.jpg
 

Kidbruv

Well-Known Member
You may need 20 pounds of Browns.
Both you an Indican3 mentioned this and I thought the same thing. But getting brown materials never seems to be an issue - it's the green I tend to be short on.

Then I started doing some reading today and now I'm really confused. I have found a couple sources that list the C:N ration of coffee grounds as around 25:1. Since the ideal compost ratio is approx 30:1, wouldn't that make coffee grounds a fairly evenly balanced Brown:Green material on their own?

Considering their huge surface area, high calcium content, and near ideal C:N ratio, coffee grounds seem to be a decent stand-alone compost material (provided they are able to be adequate aerated). Now granted they may be missing P and some other desired macros & micros, but what am I missing here?

Edit to add that I am not using coffee grounds alone - just making clear why I am confused at apparently needing to add gobs of browns to them.

Edit #2 to correct myself - coffee grounds apparently do not have a high calcium content (thanks to the link from Indican3)
 
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indican3

Well-Known Member
I haven't read through it all but my go to garden source, You Bet Your Garden, will give you some info on that http://www.gardensalive.com/product/using-coffee-grounds-correctly

Main point is: "samples of raw coffee grounds they've tested over the years all had a pH below 5, too acidic for even some of the so-called acid loving plants." furthermore "the grounds are even more acidic than those numbers imply as there is a very high residual acidity".

Aside from that "There's no life in those grounds; its all been boiled or perked away." you need organic material to break down the coffee grinds, if your medium was mostly grinds it couldn't support life and plants would need to be fed with synthetic nutes, assuming that could even work with a highly acidic medium
 
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Kidbruv

Well-Known Member
Seems to be a lot of conflicting info out there. Your article states that coffee grounds are very acidic while others say it is PH neutral. In any case I'm ok with acidic since I'm probably balancing that with the alkalinity of my wood ash.
 

indican3

Well-Known Member
Seems to be a lot of conflicting info out there. Your article states that coffee grounds are very acidic while others say it is PH neutral. In any case I'm ok with acidic since I'm probably balancing that with the alkalinity of my wood ash.
Was somewhat addressed in the article

When we first started doing this show, we warned people to only spread coffee grounds around acid-loving plants......
........But then we were sent some test results that showed grounds to be neutral on the pH scale! To find out what gives, I called Will Brinton, founder and Director of the Wood's End Research Laboratory in Maine, the definitive testers of soils, composts, and raw ingredients used in large-scale composting. Will solved the mystery instantly. Woods End, it turned out, was the source of that neutral test! Ah, but some follow-up investigation later revealed that it hadn'tbeen coffee grounds alone, as the person submitting the material for testing had stated, but grounds mixed with raw yard waste, the classic 'dry brown' material that is the heart of a good compost pile.
 

Kidbruv

Well-Known Member
Yeah I saw that, but:

From https://ag.arizona.edu/yavapai/anr/hort/byg/archive/coffeegrounds.html

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.

And from http://web.extension.illinois.edu/dmp/palette/110109.html

While coffee grounds have been shown to have a nearly neutral pH around 6.5- 6.8 (neutral is 7), coffee reportedly has a pH of anywhere from 5.2 to 6.9 depending on the type of coffee and how it is prepared. The lower the pH, the more acid, and a drop in one full pH unit is equal to a factor of 10. So if brewed coffee is a pH of 5.5 and the grounds are 6.5, the brewed coffee is 10 times as acidic as the grounds.
 

Kidbruv

Well-Known Member
While we're talking about composting, figured I'd share my brilliant stoner idea I just came up with: The Compost Muddler!

My partner has been pickling all day and leaving me with all kinds of kitchen scraps. Problem is they are in fairly big chunks and I'd like them a little more mashed up to speed up decomposition. So as im standing there with a bowl of pepper parts, carrot peels, and bean bits, I came up with this:


IMG_20160821_1427213.jpg
IMG_20160821_1430542.jpg
IMG_20160821_1431235.jpg

Voila.
 

indican3

Well-Known Member
I guess the type of beans and roast to will make it difficult to accurately predict acidity levels, too variable
 

GreenSanta

Well-Known Member
worms love the coffee grounds, in fact, I generally pile all together somewhere on my worm farm and every once in a while the coffee grounds are where I find the most worms. They also love the paper filters they use! I personally source mine from small local organic coffee shop ... who knows what starbucks put in their coffee!!
 

hillbill

Well-Known Member
Used grounds are not acidic having given that up to the brewing but they do have significant nitrogen and require drainage as they can make compost or mix soggy. I do like a little in my mix and compost most for outdoors and containers. Side/top dressing with it since gardens growing up in the '60's.
 

Beemo

Well-Known Member
check out alpaca farms. got a recipe from a reputable alpaca farms compost seller....
got it writin down somewhere in my notes... but its something like 4 to 1 or 5 to 1 alpaca shit to coffee grounds...
use to fill up huge 55gal smart pots with alpaca shit and coffee grounds with amendments like kelp, alfalfa, etc....
after a couple weeks of composting(after cooling), i throw in worms.
worms love that shit... explosion of worms EVERYWHERE... harvesting is a bitch tho...

alpaca shit is usually free... you just have to scoop it up yourself...
check craigslist or local ads....

EDIT: do not use fresh shit... let it sit for awhile
 

VTMi'kmaq

Well-Known Member
I was thinking the same thing. Too much coffee grounds might skew the ratio too far toward the N side of things. Nevertheless, carbon materials are so easy to come by that it's a nice problem to have.

So when I got to the Starbucks and spoke to 'Elaine' who was the one that would be holding it for me, she asked if I minded that there would be paper filters in with the grounds. I said not at all since they will break down. She brings out a massive bag for me that had somewhere between 10 and 20 lbs of grounds in it! I asked her out of curiosity if they give away a lot of grounds or if most get thrown out. She tells me that this was the first she'd ever heard of the program and that they throw out all their grounds. And she was a supervisor.

When I got home and opened it up, not only were there filters, but also lots of foil-type coffee packages in it. I picked them out no problem, but it tells me that they don't even put their grounds in a green bin for municipal composting. What a waste. Literally.

So anyways I put the whole big bag full into my two composers. I added some wood ash and sawdust to compensate for all the N-rich grounds. Once I get leaves in there, I think it's gonna be great.

Here's what I got...View attachment 3762317
why can't we stockpile grounds?
 

Beemo

Well-Known Member
coffee grounds can also be used for water retention.
i put coffee grounds in the fert spreading on my lawns... it helps out during the drought/heat.,.,
smells wonderful in the mornings :)

coffee grounds can also be used for organic pesticides... ants dont like coffee grounds...
 
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