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  • Farmer Vin

Compost and Coffee

In case you didn't read about it, the biggest addition to the garden this year was Pete's Composter. Yes, that's what I'm calling it now. The big, round, black, plastic vessel is our new repository for all garden waste — stuff which had previously been tossed into a crap pile next to the fence on the garden's north side. This composter so far is doing a nice job in providing a hot and moist atmosphere for the waste to rot. And rot it does. I've thrown all types of weeds, leaves, crab grass, garden clippings into it. The garden clippings are the best part because much of it includes clips from several fragrant plants including the large lavender plants, the insanely resilient mint, oregano, flowered thyme, some basil leaves that got chomped through by some bug or another, and tomato plant clippings. All these things are individually pungent, but when you toss them all into the composter, you get a scent that reminds one of a seaside candle shop or perhaps the incense-filled air in the woods around King Richard's Faire up in Carver, MA.

I learned the dos and don'ts of composting not from watching YouTube videos or endlessly reading up on it, but from my own horrid experiences, some of which I will recount here. I am by no means an expert, but I am a person who had made more mistakes than he'd usually admit to and I have learned much from those many mistakes. What follows is a little personal history followed by a number of illustrative tangents.

My Smelly Bins

I have three compost bins at home. They're nothing fancy, just two of plastic trash barrels with lids, and a storage bin, all with aeration holes on the sides, tops, and bottoms that I made using my drill. The first one I made was a plastic trash barrel. I got for like $15. Once I had it it all drilled and ready, I began filling it with as many vegetable kitchen scraps as I could. Corn cobs were my particular favorite. Then I started getting crazy throwing in melon rinds and fruit leftovers. Every night after preparing dinner, I would add more scraps like potato peels, wilted lettuce, egg shells. It was lovely to not be putting all that into the trash! I was feeling happy and all environmentally friendly, but that feeling passed quickly.

These are my backyard compost bins. Ignore the weeds, long grass, and mold on the shed.

For those of you who know even a tiny bit about composting, I can feel your disapproving nods and cringes. Yes I learned the hard way that my method or lack thereof was a recipe for some smelly trash that was not about to break down into lovely compost in a timely manner. Seriously, when I took the lid off one hot July day after having spent the past month tossing scraps in, the smell emanating from it was combination of death, aged cheese, and foot odor. It was also oozing a weird jelly substance from its lower holes onto our back deck, which attracted a species of mutant wasp indigenous to nowhere else but my backyard.

I moved the bin onto the grass at the far end of our backyard and put it up on two planks so that there was air flowing underneath and so the drippings could fall onto the ground.

No, that was not the way to compost. Although it's not exactly not the way to compost either, that is if you're willing to put up with the initial grossness and don't mind a much much much longer composting process. Fast-forward to today, and my three containers are well-balanced and smell like fine All-American dirt.

So what changed? Well for one thing I got less stupid. For another, I got to know my greens and browns.

More Brown Than Green

The mistake I made was to not use enough "brown" materials to counterbalance my "green" materials. These brown materials include dead leaves, dirt from the ground, chopped up cardboard (without printing or ink on it), torn up paper, corn stalks, wood chips, straw, pretty much anything from a tree that has fallen off it and dried up. The green materials include vegetable and fruit scraps, animal poo, eggshells, weeds, grass clippings. (Avoid using animal fats and meats. Those don't rot nicely, and they can make your compost smell like an unlicensed morgue.)

Here's the inside of one of my backyard bins. There are a few twigs in it and a couple bits of paper that could do with a little more breaking down, but overall this compost is ready to be put into the ground.

I won't get into the chemistry too much, partly because I don't know it enough to be able to write about it, but know that green compost has a lot of nitrogen and it is because of this nitrogen that the compost needs to be counterbalanced or else you end up with rancid compost that takes longer to break down. In general you want a brown to green ratio 3 to 4 parts brown to 1 part green.

To fix my initial smelly compost, I simply added more brown materials and used a garden fork to mix it in. In a few weeks time, it became less offensive. In a few more weeks time, it began to take on the dark-chocolate brown color of decent compost.

After some more tries at composting, I finally got my routine down. I start by filling my barrels/bins about 3/4 full with dead leaves in the fall. Then in the spring, I start adding to the compost whatever vegetable scraps I want to and not think about my green to brown ratio. The only maintenance I perform is to maybe give it a five-second spray of water every now and then and to run a garden fork through it every so often. If it seems to get smelly, which it rarely does, I may toss in some dirt or any dead leaves from around the yard I was too lazy to rake up (usually found between bushes). By the end of the summer I have a nice pile of dirt to spread over my garden that will enrich the soil in the next season.

Keep in mind, that's how I do it. I'm not recommending anyone do the same, I'm just sharing my experiences with you. There are plenty of bloggers, gardeners, and YouTubers who have much more click-inducing things to say on the subject.

A Visit and a Memory

So there I was in the garden week or so back, doing my thing — weeding, watering, being Farmer Vin — when from Gramatan Avenue I saw a dude running up to the fence from his car. Usually people don't run to see me or the garden but instead try to walk by quickly avoiding eye contact. This guy didn't do that.

As is my way, I gave him a hearty "Hello!".

He said, "Hey listen, I run a cafe not far from here, do you want our coffee grounds?"

Coffee grounds! My brain did about a million calculations at once, and I remembered that coffee grounds make great compost!

"Why yes I do!" I replied happily. And then from the back of my mind came a long dormant memory.

Flashback time...

Waaaaay back in the early days of my career when landlines were commonplace, Y2K was a thing, and well before I realized that a person with my writing talents was probably better off programming internet applications, I was a young associate editor working at a consultancy that was developing a new magazine for Scientific American called Explorations. It was a family-science magazine that was sort of a science-light publication for the not-so-sciency set that they could read along with their kiddies. Don't bother trying to find it, we popped out four issues, before they moved the publication to Boston and then abandoned the whole idea I think two issues later.

My main job was to keep a calendar of events for various science museums around the country, which is why to this day 22 some-odd years later, no matter where I am in the U.S., I always know where the nearest science museum is and what's worth seeing there. Anywho, one of the other editors was a very talented individual named Jake.

Jake is a ridiculously intelligent guy of much depth whose qualities and quirks are far too numerous to list here. Just know that he is a fun guy to do science experiments with and is a great editor to boot. Come to think of it, he's also a gardening enthusiast. Every now and then we got to write articles on various topics or little blurbs here and there. Jake being the more senior of us, and frankly the more capable and experienced, got to write more than a few good ones. A particular article I remember Jake writing was one called "How to Make Dirt". It was, as the title implies, an article teaching families how they could go about making their own dirt, or rather compost.

One of Jake's quirks was that he didn't just write and research articles as he more or less method-acted his way through them. For this particular article Jake attended compost classes, stored a large plastic bag full of god-knows-what in his drawer, and kept a large wriggling worm bin under his desk. Far less disturbing, he also kept a ziplock bag in which he was doing some quickie composting that kids could do easily at home without having to take classes or have dirtboxes with invertebrates under their desks. This plastic ziplock bag contained coffee grounds as its main base compost material, and then later came to include other bits of plant matter. But the coffee was the most interesting part because after only a week, it really smelled like dirt! Like, waaaay more so than I ever would have thought. To this day, that bit with the coffee info stuck with me as does the scent of what was inside of that long-lost ziplock bag.

Scott and the Never-Ending Brew

So that's what came to mind after that garden visitor offered the coffee grounds to me through his masked visage as he stood by the garden fence. Turns out his name is Scott, and he owns Booskerdoo over at 76 Craft Ave, near the corner where it meets Park Place. Our conversation was brisk and truncated as he was parked illegally, but before he departed I gave him my "Farmer Vin" card and kindly requested he get in touch. A day later I got a call from a woman named Michaela who works for Scott. She told me they had some grounds ready. The next day, a Saturday, I went to collect them.

Here's Pete's Compost bin with a container of used coffee grounds from Booskerdoo.

If you thought the BGG compost smelled good before, you ain't smelled nothing until you've smelled BGG compost spiked with Booskerdoo cold brew. I mean the coffee itself was exceptional, but the grounds made for a nice, aromatic, full-bodied addition to the compost.

Scott told me that we could have all his coffee grounds, which is great but also a little problematic. By my calculations, if I kept getting twice weekly doses of his grounds, our compost bins would be overflowing before August. So I will have to limit the takings to every other week or less to let what we have break down before overwhelming it again with what I think is a coarse-ground South American blend (I should really ask). The overall benefit to this hopefully long-term arrangement is that we may end up creating enough compost of our own to feed our future crops, which will push us further toward full carbon neutrality for the garden, while at the same time making the garden more locally sustained. How cool would that be? Then we could all feel better about our collective caffeine addiction and not have to rely completely on horse poo from Bedford.

Almost Too Much of a Good Thing

Coffee grounds are considered "green" compost, which can be a problem since you usually want less of them and more of the brown. Luckily, Pete's Composter is big, and we happen to have a ready supply of "brown" material from the dirt from the pile we previously cleared, along with enough dead leaves to carpet a modest two-bedroom apartment. However, if we were to go by conventional ratios and practice, it wouldn't be enough to deal with the onslaught of coffee grounds over time. Fortunately, I am not ruled by convention.

This image makes me happy. It's our BGG compost with the coffee grounds. After I dumped it in, I mixed it up a bit with a garden fork. The next day I added some leaves and crushed up twigs to it.

As of now, I'd say our BGG garden compost ratio within Peter's Composter is close to 1 green to 2 brown because of the coffee, that is, if we were to go by traditional ideas of greens and browns. Here's where I differ from most other gardeners, I put used coffee grounds in a sort of sub-category of green compost materials with its own properties, and not just because it actually looks like dirt. To begin with it's roasted, so the breaking down process has already progressed past the initial cell-wall breaking stage. Most of the oils have been removed in the brewing process and were happily consumed by the drinkers, so there's a slightly less chance of oils going rancid in the pile. If you keep it moist, it fuzzies up pretty quickly with fungus, which is what you want to happen. Also, it binds to brown materials better than most other green additives, which in my experience seems to speed its breakdown.

Ground Exposure

If our BGG compost was not exposed to the ground, I would probably be a little more reluctant to add so many grounds. If these were my home-made compost bins, I would probably aim to make the ratio more in favor of the brown material that it currently is. But Pete's Composter is open at the bottom which allows microbes and bugs present in the garden dirt to come up into the pile while allowing it to drain out easily. So I feel as if I can get away with adding more coffee to the BGG compost than I'd otherwise use. To be safe, I have a backup plan in case I'm completely wrong and the coffee doesn't break down the way I think it will. If worse comes to worst, I'll just flood the bin with brown material and get a more traditional mix, and mix thoroughly any leftover grounds in our open bin with our old pile of dirt.


Some people claim the opposite of what I'm advocating and that used coffee is terrible for gardens. I've also read a lot of articles stating categorically that earthworms, which you generally want in your compost, hate coffee grounds and will avoid them at all costs. Lastly there are many who say you need to tread carefully when using coffee because it naturally contains complex chemicals that can play havoc with a compost pile.

Well, anti-coffee opinions I'm going to ignore because I've had nothing but good times with coffee in compost. As for the worms, let me just say that I've not noticed a lack of wormage in our BGG compost bin. In fact just this past Thursday morning, when I turned over the compost, I found several gigantic worms happily munching through the highly coffee-fied pile. Not a word of a lie here, I thought one of them was a baby snake before I realized it was just a really well-fed earthworm.

My new friends in Bronxville.

Finally, for the ones who say to tread carefully, I say that I couldn't agree more! The key to composting no matter the ratios or science is to pay attention to the compost, and adjust as needed. There's no magic formula for having stuff rot in a bin, just be sensible and balanced and maybe try to remember some of the high school biology you thought you'd never use. If it smells bad, add more brown materials. If it smells like dirt, you're doing it correctly. If your neighbors complain, you should probably move your bin to the other side of the yard. Don't get bogged down with trying to get ratios absolutely correct. Leave that level of detail to the professionals who have big composting operations and as a matter of economics need to worry about this stuff. For folks like us, our noses will tell us what to do.

Again, that's just my experience and opinion. I take no responsibility for anyone who decides to go full Maxwell House all over their yard. Common sense and a willingness to spend time is what's needed, not some guy's words in a blog. If you'd like a decent resource for composting with coffee grounds, give a click to this link here. They do a good job of summing up the general facts.

Thanks to Scott over at Booskerdoo for giving us his used coffee grounds. It's a great example of a small business turning their waste into something useful, and another reason why Bronxville is the bees knees when it comes to Giving Gardens. Finally, thanks to my friend and former co-worker Jake for showing me that compost experimentation is a good thing and that office worms are not to be feared.

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