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m_lorne

Compost - coffee grounds good enough?

18 years ago

Hello all,

I have been doing a great deal of reading about composting over the last few months, but still have some questions. I have constructed a 3x3x3 box and I have lots of brown carbon material (dried leaves, old plants, etc.). However, I am pretty skimpy on the greens. My kitchen does produce a good deal of greens, but it is not nearly enough to fill the space. By my calculations based on layering 5 inches of green, 1 inch of soil, 1 inch of manure, and 5 inches of brown, then I will require around 11 cubic feet of both brown and green.

So far, my best source of greens is the local Starbucks (boo on Tim Horton's for just throwing the grounds in the landfill). They can give me about 6 cubic feet per day if I want. However, after reading in the Square Foot book about compost diversity, I'm wondering if a single source compost like coffee grounds will have a balanced range of nutrients.

Then, I contacted a local grocery store to ask about their greens. They can give me some leafy greens and such, but I'm wondering about the pesticides on the vegetables. It is a pretty sad comment on our food system when I am hesitant to put the same food in my compost that I serve to my family. Obviously I wash my veggies before serving. So should I wash the greens before dumping them in the bin?

Thanks for all of the help.

Michael

Comments (11)

  • 18 years ago

    It's better to use a variety of sources to make compost, but if coffee grounds are what you've got, they'll make good compost (maybe not ideal, but good).

    I think most pesticides are destroyed by the composting process, at least if you get a hot compost. I'm not sure of this, but I seem to recall somebody posting some links to studies on this.

  • 18 years ago

    Michael said:

    "By my calculations based on layering 5 inches of green, 1 inch of soil, 1 inch of manure, and 5 inches of brown, then I will require around 11 cubic feet of both brown and green."

    I would do it a little different were it my pile. Based on a 3:1 ratio, I would put three (3) inches of browns then one (1) inch of greens until complete, then wait for the smoke to start coming out. If it doesn't get hot I would add more greens. And too, it is my understanding that manure (animal) is a green as well. Then there is the issue of one (1) inch of coffee grounds; that is a awful lot of coffee grounds in that size bin. I just sprinkle my grounds throughout the pile as I build it; but one could layer them, just remember the grounds are a green too.

    There are many ways to construct a compost pile, I speak of how I construct mine. Experimentation is the best teacher, just remember how you did it and in time you will have a formula (technique) that works best for you...

    Blutranes

  • 18 years ago

    Your mixture includes manure, which is also a green.

    If you are looking for other sources of greens, there is another thread on this forum about pee. A controversial, but very strong green that everyone has available for free.

    Another free green is lawn clippings. Though I usually mulch my grass clippings, if I was hurting for greens, I might consider putting the bagger on the mower and adding a bag or two of grass clippings to the compost. Lawn clippings are another great source of free greens, that most people have access to.

    Some people steal the bags of grass clippings that are left on the curb by neighbors. But again, if your concerned about chems that may not be the best option for you.

    BTW, I would skip the soil layer.

  • 18 years ago

    I just completed buidling a 3 bin system as well. Our lawn pickup is on Monday nights, so my son and I drove around the neighborhood and got about 50 bags of leaves and grass clippings. Took us all of an hour. Its amazing what people throw out, although we did get quite a few strange looks as we proudly shouted, "leaves!!! yes! more browns!!!" We filled up 3 bins and have about 20 bags of leaves and clippings left over. We are trying to stock pile the browns as people are still raking up their winter leaves. All of this we got within 1/2 mile of the house.

  • 18 years ago

    In your calculations do not forget that even your "browns" will contribute some Nitrogen, although I do find that I need to supplement with a good N source, manure, blood meal, or something else, to get good bacterial activity. If I were to leave the material to just get digested, in a couple of years, I'd not concern myself with added N.

  • 18 years ago

    Blood meal, alfalfa pellets, rabbit food sold in the pet department, grass clippings, grocery store throw away greens like lettuce etc.

  • 18 years ago

    There was a analysis of coffee grounds a few years back. Probably still out on the Net somewhere.

    WOW! That is the first time I got what I wanted from Google listed #1.

    Sunset.com
    But not the analysis I had seen before.

    Bob

  • 18 years ago

    I'm not a huge fan of using coffee grounds as a green. A true green IMO quickly becomes a hot gooey stinky mess if left in a pile on its own (well, maybe not gooey if it;s manure).

    My big pile of coffee grounds is just sitting there at ambient air temperature, patiently waiting for me to use it.

    I'd take the grocery store greens, and/or pee on it...

    Cheers,

    Tim

  • 18 years ago

    Used coffee grounds are my favorite 'green'. Fresh cut grass is my other favorite green, but it is not available year-round as the grounds are.

    Starbucks can provide a 100 pounds a week, if you collect them properly. That means you get on good enough terms with the employees to have them understand you will be glad to take ALL the grounds they can provide. Otherwise they will give you one bag a visit. I have not been in the store in three years. My hatchback contains a couple of Rubbermaids and a long-forked tool to grasp the knot in the grounds bag. It takes practice to get the bag out without ripping it open, even with two bags used. The bag is lifted out of the dumpster into the Rubbermaid container. If any grounds or trash are spilled on the ground, they are cleaned up with a brush and tray. Starbucks does not directly encourage gardeners to collect out of the dumpster, and one has the responsibility to leave the dumpster as one finds it. On one visit to the store, no grounds were available and I asked if I could look in the dumpster. Five bags were in it, and on future visits I never went back in the store for fear that some legal-minded employee would tell me differently.

    Interestingly, the grounds in the dumpster are more to my liking than the bags the employees give you. The higher moisture content means they do not clump up the way the espresso grounds do. On the other hand, the bags of loose grounds and filters found in the dumpster also have trash in them.

    The average person who goes into Starbucks and is given a bag of grounds (some of the new fancy silver bags only hold about seven pounds of used grounds) probably is not aware that Starbucks trashes 70-90% of used grounds (my estimate)

    Seven-bin Bob

  • 18 years ago

    Coffee gounds are super. I've been filling a raised bed and I throw coffee grounds straight in there. I also mix it with potting soil in crazy amounts because my husband drinks coffee like there's no tomorrow.

    I use leftover coffee to water the plants.

  • 18 years ago

    This is called paralysis by analysis. All these months and you don't have compost yet?

    Coffee grounds can be used DIRECTLY in the garden as a fertilizer. They have the same protein content as corn meal. I would not waste them in a compost bin. The application rate in the garden is one heaping handful under the canopy of every small bush, once a month. For the lawn you can apply at 10-20 dry pounds per 1,000 square feet. If you don't dry it then apply at 20-40 pounds per 1,000 square feet.

    You should not have to buy new stuff just to dump it into the compost. Compost is supposed to be made from waste materials. It is recycling. If you need greens, find someone who bags their grass clippings and don't worry about whether or not they used herbicides on it. Just do it. Or find a stable where they will let you take away their freshest manure. If you claim you can't find a horse stable, give me the county and I'll make one phone call to the sheriff and get a dozen phone numbers for horse stables. The sheriff always has a mounted posse on call for search and rescue.

    I collect horse manure using a roll of 9-gallon plastic trash bags, one 5-gallon bucket, and a shovel. I line the bucket with one or two bags (depends on how much I trust the bag), then I fill the bag with 2 to 3 gallons. Any more and you can't carry it. Tie off that bag and reline the bucket. Continue until you fill your trunk. This goes a lot faster with more people, more buckets, and more shovels. But you want the stuff that is still steaming to really heat up your pile.