Friday, March 20, 2009

Coffee in the Compost

I would really like to thank Starbucks and all the caffeine addicted Portlanders that help my compost smell wonderful. Yesterday I picked up two bags of spent grinds from the local shop. Portland is one one of those places where a lot of people garden and the bins that hold these grounds are often empty. So needless to say I was quite happy to discover a Starbucks location that I guess isn't frequented by many gardeners because it seems they always have a bag or two for the taking.

I've been reading a bit on the merits of coffee grinds vs. manure and have discovered the following.... (Please keep in mind this is from reading other blogs so I'm not sure the scientific verification of any of these - please take with a grain of salt.)
* Coffee is better because it lacks the pathogens that can be found in manure.
* Manure adds more salts to the compost.
* A well managed compost pile will get hotter with coffee then with manure.
* Coffee grinds attract more worms then manure. (Guess worms are little coffee junkies too!)
* Caffeine found in coffee is in fact the coffee plants natural insecticide and while most of it is leached out into the coffee during the brewing process, some remains and helps ward off garden pests. (This one I have to question - not sure that enough caffeine survives the brewing and composting process to make a difference.)
* Coffee beans are in fact a seed. Seeds are ounce for ounce more densely packed with nutrients and minerals then other plant materials, (they have to start a whole new plant from "scratch"!) therefore putting them in the compost makes your compost more "nutritionally" dense as well. (or something like that - heh)

All that being said, I do love coffee in my compost. However gardeners have been using manure for millennia with much success and coffee's only been "around" for about 500 years. As long as you get your pile hot enough to kill the pathogens that might lurk there I'm all for manure in the pile too.


Randy Emmitt said...


Real good article and nice compost! Myself I don't drink Starbucks coffee, they don't serve shade grown coffee that is better for our song birds while wintering in coffee lands. But I'd certainly take their grinds. We consume about 3 lbs a month so we have lots of coffee in the compost.

Just Jenn said...

I actually buy from a local roaster (Stumptown Coffee) for all my personal at home coffee needs. ;^) Their coffee is all either organic, shade grown, fair trade or a combo thereof. Plus they were voted best small roaster in the US a few years ago.

However Starbucks does have the free grinds and they are everywhere so when I occasionally go out for coffee it's usually where I wind up.

engineeredgarden said...

I like the UCG's too! As a matter of fact...I've got a 5 gallon bucket full to the rim on hand, that will be used for the next batch of compost. I'm going for some fresh hose manure, too! Good luck with your pile.