Laidback Gardener Tip of the Day

The Cadillac of Composters

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This looks just like my old tumbler (why didn’t I ever take a photo of it?).

I’ve had all sorts of composters over my long gardening career, but the best was my compost tumbler (rotating composter). I actually won it as a draw prize at a garden club meeting about 20 years ago. It finally died 2 years back, a victim of rust. I know I could make a new one out of a recycled plastic or metal barrel, but… I haven’t gotten around to it yet. But I really should, as a compost tumbler simply is the best way to make compost.

A Word About Compost

The first thing to understand about composting is that plant material will decompose no matter how you treat it. (The second thing is that it will decompose best if you chop it up ahead of time, but I digress.) In no time flat, millions of microscopic organisms (bacteria, fungi) will take up residence inside your compost pile, devouring and recycling it. But they work fastest when oxygen is widely available. If you just pile it up and wait, they’ll soon use up all the oxygen that is available and then the composting process slows down. Way down. In fact, it can take years to completely decompose a compost pile that is left on its own. So theoretically, you’re supposed to mix the material frequently, as this action will add plenty of oxygen to the pile.

I suppose if you’re composting on a grand scale, you could simply dump your compost in a big pile and use a front end loader or a tractor with a compost turner to mix it: then it would be done in no time. But the average home gardener doesn’t have that kind of space and has to make do a modestly sized compost bin that no automated compost mixer will fit into. That means turning your compost regularly yourself, with a shovel or garden fork: not an easy or comfortable task. So most people rarely do it… and certainly not weekly, as recommended. And thus the composting process slows to a near halt.

Giving Compost a Tumble

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A homemade model. Note there is room to put a wheelbarrow underneath when you empty it. There are plenty of DIY plans on the Internet: here’s one.

That’s why compost tumblers are so remarkable. You can give them a spin in seconds, so they quickly and easily mix your compost materials. The result is that they heat up considerably and composting proceeds at lightning speed… well, for compost that is. Experts claim to have a finished product in 2 to 3 weeks! I usually figure 4 to 6 weeks… in mid summer. (Composting slows down considerably in the fall, when temperatures drop.)

The neat thing about a compost tumbler, at well-designed one at least, is that it is simply sooo easy to turn. Every time you walk by, give it spin. Maybe daily, but certainly at least two or three times a week: you choose.

But how do you know when the compost is ready? First of all, you’re getting close when the barrel no longer gives off much heat, even in the hours after you rotate it. By the time its contents are brown and uniform and you can no longer recognize its original components, you have compost!

Two Bins Are a Must!

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You still need an accumulation bin.

Even when you have a compost tumbler, you’ll still need a second compost bin, just for accumulating compostable materials. In fact, however you compost, you always need two bins. I don’t know why no one ever seems to explain this to beginning composters, but you just can’t keep adding fresh material to a working composter or it will never finish: it will always contain fresh material that is not ready for the garden.

Instead, you need a working bin, one you actively turn over, but to which you never add new material, and an accumulation bin, where you put the fresh stuff. You don’t need to turn the material in the accumulation bin: you’re just stocking material there and it will only be composting at a minimal level. But this is where you build up your compostable material so that, when you empty your compost tumbler, there’ll be enough new material to start a fresh batch.

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This commercial bin has two compartments. One for accumulation and the other for composting. The bins are awfully small, though.

So here’s the routine. Fill your compost tumbler two thirds full of material (never much more than that or air won’t circulate well), then turn it regularly, but add nothing new. Instead, add all fresh kitchen scraps, fall leaves, garden refuse, etc. to the accumulation bin. Keep turning the tumbler until the compost is ready, then empty it (the best compost tumblers are raised off the garden so you can simply dump the finished compost directly into a wheelbarrow) and use the compost in your garden. Then fill it to two thirds full again, using material from the accumulation bin. It couldn’t be simpler!

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, laidbackgardener.blog will continue its mission of demystifying gardening and making it more accessible to all.

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