Bentley’s “Ultimate” Backyard Worm Bin

Things have settled down a little on various fronts, so I’ve found myself with a bit more time to “play” (i.e. time to start fun projects that I can write about here). The first thing I’ve been working on is a continuation of last year’s “Cardboard ‘n’ Coffee Vermicomposting” project. As some of you may recall, last July I basically just tossed stacks of cardboard drink trays into my big wooden backyard bin – along with other materials, including a large quantity of coffee grounds – in an effort to see how long it might take Red Worms (and other critters) to process the cardboard. OK, I also just generally needed some place to put all those stacks of trays! lol.

As is often the case with my fun projects, I basically forgot about the bin and moved on to other things – at least until later in the fall, when I needed a spot to dump a surplus supply of coffee grounds (I was continuing to pick them up from a local coffee shop, but my winter bed was well stocked by that point).

See a pattern emerging here?

As things started warming up this spring, I finally started treating the bin more like a vermicomposting system than a garbage can (lol), adding deposits of food waste along with more coffee grounds, and the level of material seemed to drop a fair bit. That’s not to say it was remotely close to an optimized worm bin though – as per usual (when working with lots of coffee grounds) everything overheated and I ended up with lots of grayish, dried-out grounds, and barely a worm in sight!

A short time ago I decided that enough was enough – it was time to finally get the bin working properly! Thus began the creation of “Bentley’s ‘ultimate’ backyard worm bin”!

In spite of the difficulties I was encountering with the coffee grounds, I knew the contents of the bin would actually provide me with a great starting place for creating a top notch worm bed. I figured all I’d need to do – at least initially – was to mix in LOTS and LOTS of shredded cardboard/paper, and to add LOTS of water. No “food” of any kind – just bedding and water.

I must say the strategy has actually worked out quite well so far! The contents have continued to heat up, but not quite as much as before, and when I turn everything over it actually looks (and smells) quite good.

Today, I decided to take things one step further by lining the inner walls of the bin with sheets of cardboard. Normally it’s just slats of wood sitting between the contents and the outer environment, so everything stays pretty dry around the outer perimeter of the composting zone – especially when there are lots of coffee grounds. With the inner cardboard walls, the bin should still be able to “breathe”, yet retain a lot more moisture (another advantage of mixing in so much shredded cardboard as well).

Once my inner wall was in place, I felt inspired to mix in even more shredded cardboard (and water down yet again).

My original plan was to continue mixing in bedding until the bin was essentially full. I’m starting to think this might end up taking longer than expected, though! As the system becomes more and more optimized it seems to be composting more and more effectively – so the level of materials has continued to go down.

Nevertheless, I’m already having a LOT of fun with the project (feels like the “good ol’ days” – haha), and can’t wait to see how the system turns out. It seems as though the worms are already starting to move into the bin again, so I don’t think it will be too long before the bin is crawling with them.

Will keep everyone posted on my progress!

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    • Liz
    • April 26, 2012

    I have a bin I am doing the same thing with, bedding only. Well, I do use some grains occasionally. I started it to see if I could minimize bugs this way. I am anxious to see your results.

    • Steve L.
    • April 27, 2012

    Nice Bentley! This bin sounds like the perfect place to take some of the compost and feed to your herd. I often grab a handful or two of my mostly to completely finished compost and dump it in a spot in a worm bin, and spritz with water. 2-3 days later when I pull back the bedding this area is undulating as the worms chow down. You’re creating ultimate worm chow in your ultimate worm bin! Very cool.

    Thanks for sharing a good idea of what to do with excess materials.

    • John Duffy
    • April 29, 2012

    How long do the coffe grounds continue to heat-up?

    • John Ski
    • May 2, 2012

    Here is an idea to be the ultimate. There is a guy on youtube that sells plans for a worm bin that rolls over so that he can scrape the good vermicompost from beneath the removable bottom. It seems like a brilliant idea when you watch the video. You could easily modify your bin to do the same function by screwing some circular cut 2x12s to the front and making a removable bottom.

    My ultimate worm bin is a Bio-Orb Composter – 36″ Dia. This holds 97 gallons of material. It will never rot and holds the moisture in nicely. I thought this was the world’s worst regular composter because it is impossible to move with finished compost. I started using it only to age or hold compost from some tumblers. After being lazy and dumping some wormfactory trays in there I notice an explosion in worm population and the look of the material. I have been able to worm compost outdoors all winter for the last 3 years by filling it to the top with compost, cardboard and small amounts of food scraps in the Philadelphia PA area. Each spring I have a huge amount of finished vermicompost to top dress some raised beds. I allow sun exposure in the winter only.

    • Steve K
    • May 8, 2012

    I am glad to hear that things have “mellowed” in your life, and that you are up to your usual hijinx! Keep it up, Bentley. You inspire us all.

    • Bentley
    • May 8, 2012

    LIZ – this definitely won’t be bedding-only, but there certainly WILL be a high proportion of bedding materials!
    STEVE L – yeah, I think this stuff will be pretty tasty for the worms. Will have to test it out as a food in other systems.
    JOHN D – good question! It seems like it’s a LONG time! haha
    This system seems to finally be settling down a bit in terms of heating (and more worms are moving in), but I’m always surprised by just how much heating potential coffee grounds seem to have.
    JOHN S – I have never tried a Bio-Orb. Sounds like a great way to make yummy worm food though!
    STEVE K – it never fails – whenever I say things like that, a whole mess of new craziness seems to fall in my lap! LoL
    Oh well – slowly but surely, progress is being made!

    • Gina W.
    • February 21, 2013

    Hi Bentley, I’ve got an outdoor wooden bin question.
    I’ve read your concern with cedar wood oils but I have 6 year old outdoor cedar fencing slats that are quite weathered and structurally sound. Do you suppose this aged wood can be used to make an outdoor bin? I would line the inside with cardboard. Then surround the entire box again with wood in order to stuff it with an insulating-material barrier. Your thoughts?
    Thank you!
    Gina W.

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