Acidity of Coffee Grounds
Posted: Mar-03-2004 at 12:47pm
I have heard many times that coffee grounds are highly acidic. In fact many times I will put grounds around my blueberries and rhodys.
Last year I topped my compost pile off with buckets and buckets of coffee grounds. I had pumpkins volunteer in the pile and grow like gangbusters so if the pile was acidic it didn't seem to slow the pumpkins down.
It would be interesting to know just how much acid coffee grounds add to our already acidic soils. Is it enough to worry about or as the grounds break down do they neutralize?
Posted: Mar-03-2004 at 6:34pm
Now what time of year are you asking about? Our 10+" of rain in Oly last October, our 3" in Feb., or our 2+ months of dry weather last summer when you went environazi and only watered twice a month with a can?
Before you get too mad at me, remember in the PNW, it all depends! Do you have sandy soil that holds less than 0.5" of water per foot of depth or clay that can hold 3" of water per foot.
Sandy in (normal) winters I would not worry much about. Clay in dry summers might be a problem if you drip irrigate because your city water costs so much. If you overhead water, remember that clay also holds onto the calcium that washes right out of my sand so you may end up near neutral. Do a soil test now and then to see your results.
As in most diets (but mine), all in eration. My diet philosophy is slightly different. It seems that too much of something is bad for you. Therefore, large quantities of everything give me a balanced diet. Maybe I am a "sandy old man" instead of a "dirty" one?
Posted: Mar-04-2004 at 12:39am
LOL, Gary. My diet philosophy is that no diet is balanced unless it contains chocolate!
Interesting question, Debbie. I have a bag of grounds from Starbucks to add to the garden. Maybe I'll test them in the bag first and then later in the garden and see what results I get. Remind me, though, I'm liable to forget!
Posted: Mar-04-2004 at 4:00pm
I've used coffee grounds in my worm bin, in the compost pile (large quantities with leaves) and dumped right in the garden. So far I've had nothing but good results. Deb, since you've been using coffee grounds for quite some time, have you had anything fail to thrive? Especially something that would have not been so much an acid lover? It sure brings in the worms. I did get asked once when I was picking up some grounds from a coffee shop if it made the worms "wired". I don't know but they sure seem to love them grounds! Are we creating worms with coffee 'habits' oh no, the guilt!
Posted: Mar-05-2004 at 12:39am
Wired Worms. Worms with coffee habits. LOL, very funny. I do potatoes in one of my piles. They grow great in the compost bin. I thought maybe they would get all bug eaten and wormy or something> but they are better spuds than we ever grew at home when I was a kid! I keep more than one pile at different mulch stages. It's the best dirt in my yard 'cept for one lone vegi garden bed that I worked real hard at amending. All our coffee ground go in the mulch piles.
Posted: Mar-11-2004 at 5:02am
Now we have solid info from the source. In his PI column today, Chris Smith, gets a message from another Olympia resident, "just read the Starbucks label!"
On their grounds bags they have printed:
"Coffee grounds are a nutritional additive for your soil. During the brewing process, most of the acidity is removed, leaving used grounds with an average pH of 6.9 and a carbon-nitrogen ratio of 20-1. Directions: Add grounds directly to your garden. ... Apply this 'green' material as a side-dressing to nitrogen-loving plants, including most perennials and allium plants. Balance the nutrition of your soil with 'brown' materials such as leaves or dried grass.
"Or to your compost ... Combine with 'brown' materials in your compost pile. Use grounds within 2-3 weeks of brewing to capture the most nutritive value.
"For more information visit Starbucks.com/aboutus/compost.asp."
Gardeners who soil test will remember that 7.0 is neutral.
Posted: Mar-11-2004 at 10:54am
Great info, Gary, thanks for sharing. I've got a bag from Starbucks ready to go to the garden and now I'll know what to do with it instead of just guessing.
LOL, Theresa, I just read your post about worms with a caffeine habit! Hey, what else should we expect from worms who live in the biggest coffee loving region in the states?
Posted: Mar-11-2004 at 11:47am
I am laughing just thinking that Starbucks is giving gardening advice.
Thanks Gary for the information that answers a lot of questions. Next thing you know there will be a Master Gardener at every Starbucks on every corner. . .
Posted: Mar-11-2004 at 4:54pm
I'm sure they pulled a consultant in to give that advice.
Gary, thanks for reminding me! My mind is going...BIG TIME. I read that, oh, not more than a month or two ago and promptly forgot!!! Good grief I'm only 41, what will the next few decades bring.
Posted: Mar-12-2004 at 9:23am
Be nice to Starbucks! Beside that their CEO was a college classmate of mine at Centralia and UW, just think how easy it is to get a birthday present for your future son-in-law in two minutes as I did last Sunday.
Seriously, beyond encouraging gardeners to come into the stores (& smell if not buy coffee), they get free waste collection services. At today's municipal garbage rates, that is a considerable savings compared to researching and printing some labels on the waste bags.
Posted: Mar-12-2004 at 9:40am
I didn't mean disrespect them. I like Starbucks! I patronize their stores and am happy they make the effort to make grounds available. I also have a generally good impression of them being a good corporate citizen--just a healthy cynacism of large corporations.
Posted: Mar-12-2004 at 1:09pm
I think joking about them won't harm their image. I don't go to them to often because we don't have one near us. I know surprising eh?
I have a local espresso stand that gives me ALL their grounds. I ended up buying 5 gallon paint buckets with tight lids on them and gave it to them as it made hauling the grounds better in my open truck bed then the open buckets they used.
Speaking of which today is go get grounds day.
Posted: Mar-12-2004 at 2:03pm
Hmmmm - sounds like Grounds Hog Day! :)
Posted: Mar-13-2004 at 9:12am
Great information I can't wait to see my friend that works at a coffee shop. We have starbucks and about 50 zillion other shops. I have buckets with lids hanging around here. Thanks to Gary for the info. And screaming eagle... I am 48 I think, LOL I have a hard time remembering. These days I write EVERYTHING down if its important!!!! Don't worry- it won't get better- but you'll adjust. Happy Gardening!
Posted: Mar-15-2004 at 10:22am
Another note about coffee grounds: I notice some batches will be very brown colored and some will be quite black. I use the brown ones more in my compost pile to mix with high carbon materials like leaves and the blacker ones in my beds. I got large batch recently that was quite black and had an especially nice texture. I spread these around a bed that has bulbs getting ready to bloom and it really made the green stand out and I bet the blooms will look twice as lovely!
Posted: Mar-23-2004 at 12:42am
OK OK I made a good deal !!!! A friend who works at a local coffee shop is saving me grounds. I am making her nascar rusty wallace gifs and sigs in trade. Easy for me. So- cool!! She wanted to know how much I wanted. LOL. (I thought saying truckloads would scare her.) I told her I would take all she wanted to get- just not to put herself out. She said I didn't have to go scrounge through their garbage. Yaaaaaa for friends!! Guess we will have a bunch of worms doing their work wired on coffee. LOL. I am eyeing another coffee shop where my son knows the owners. LOL. Good info page from starbucks!
Posted: Mar-27-2004 at 2:52pm
Wired worms or no, clay soil or no, I use coffee grounds to deter root weevils from the Rhodys. I read that a ring of coffee grounds on top of the soil prevents root weevils from climbing the trunk of the Rhody. I haven't had a munch line on a Rhody leaf ever since...two years going on three. No scientist here, just a morning coffee drinker who likes Rhody flowers and foliage. I did ask a scientific question once though - Do the coffee grounds give the Rhodys that little extra boost in its gross stage or after the grounds break down. I was told 'after.' When I was growing up in northern MN, we used to keep our night crawlers for fishing in fresh coffee grounds, before they were used to make coffee. The worms love coffee, so maybe the used coffee grounds are really for the worms who do so much silent work in our soils that the list is just plain endless.
Posted: Mar-31-2004 at 8:12am
(crosses her heart and spits in her hat and repeats this mantra....) "I will NEVER throw away coffee grounds again!"..........LOL
Looking thru the yellow pages for coffee shops as we speak!