The Urban Compost Tumber

– Posted in: Tools and Equipment

Readers of this blog know I tend to get absorbed in the details of garden projects. But somehow the making of compost has been immune to such obsessions. To my mind, compost just happens. I don’t really give it much thought. It might occur to me in the spring that the piles should really be turned and moved to the next bin, or, it might not. Consequently, our composting “system” looks like this:

Image of overgrown compost bins

The only decent compost here came from the municipal land fill where they compost tree trimmings and such. Since our compost piles don’t build up enough heat, the seeds from last year’s vegetables survive the winter and grow to take over the bins.

Am I competent to review this?

So when Chris contacted me and asked me to review the Urban Compost Tumbler, I was hesitant. It looked like a well thought-out design, but would a laid-back–all right–lazy composter such as myself, really be the best person to do such a review? I don’t stockpile green and brown ingredients, and carefully layer them to the ideal height and depth. I don’t chop anything up. Grass cuttings get left on the lawn. And leaves? Well, we don’t have many big trees, so my kids go over to the neighbor’s, get her leaves and bring them back here so they can have a decent pile of leaves to jump in. I kid you not. In a good year I will eventually snag some of those leaves to mulch around my hydrangeas and native woodland plants. In a bad year the snow flies before anyone does anything, and we rake soggy leaves off the lawn in the spring.

Image of compost tumbler designBut Chris insisted he just wanted an honest review. Well, I never made clear to him the depths of my compost depravity, so perhaps he didn’t have enough facts to make a fully informed insistence. I was flattered to be asked, I like getting stuff for free, I was certain I would be honest, and I told myself I would try really, really hard to scrupulously follow the directions and give the tumbler my best efforts. So I agreed and sent him my shipping address.

The tumbler arrived on March 20th, but there was still snow on the ground and it was cold, so the two big boxes were parked on the porch, waiting for a good time to assemble the tumbler. My fifth oldest child, let’s call the young man the Martlet, does not readily tolerate excessive clutter, and took it upon himself to put the thing together about ten days later. Unfortunately, I wasn’t home at the time, so there are no photos of the assembly process.

Clear, well-illustrated directions

The directions are well-illustrated with clear photographs. I suspect the Martlet didn’t even read the words, but just followed the illustrations. The directions included with the tumbler state that the two halves of the barrel fit snugly, and that it may take some time to get them securely fastened together. My son professed to have no trouble with it, but upon closer questioning did confess to needing to put all his weight on it at one point. This is a clue that if strength is not one of your-er, strong points, you might want to line up some help when it comes time to assemble one yourself.

One thing that did concern me was finding a level place where it could be rotated on a daily basis without becoming unstable. Since we live on the side of the hill, level spots are few and far between. I spent some time wandering around, and finally decided there was a suitable sunny spot right next to the other compost bins. In the photo above, the tumbler is just out of sight on the left.

Time to fill it

April 2nd was the moment of truth: time to fill it. Personally, I thought it was a bit on the early side, but Chris wanted me to do the review by the end of May. (Um, yes, I do realize it’s quite a bit past May.) I thought he was being overly optimistic, and told him so, but he emailed back, “Well if you place the composter in full sun, and put a little finished compost in it as seed material, it should still go fast even in the cooler temperatures, especially if you remember to turn it daily and use a good mix of green and brown materials.” I read the instructions carefully, because I didn’t want this composter to be handicapped by my incompetence.

Uniform particle size a plus

For ideal composting results, prepare the material so the particles are approximately 1/2″ to 2″ inches in size. Well, I knew that wasn’t going to happen. I don’t own a chipper/shredder, and the lawn mower was still in the shed, emptied of oil and awaiting its spring tune-up. So I’ve already got one ding against me for improperly sized particles. You should start by leaving a little compost (seasoning) in the barrel from the time before. Since this was the first time, I couldn’t literally comply, but I hacked off a frozen chunk of last year’s most rotted compost and tossed it in, hoping it would somehow compensate for the lack of proper particle size.

Equal amounts of brown and green desirable

Begin by putting in equal amounts of ‘brown’ and ‘green’ material. Brown was easy to come by; there were the remains of last year’s perennials all over the garden. I quickly amassed a wheel barrow full. Green was much more difficult. The ground was still frozen and the grass hadn’t greened up. The few weeds that had greened up were difficult to pull from the still frozen soil. In the end I decided to use the most recent food scraps that had been tossed on the traditional compost pile.

Dampen if needed

About every 3″ to 5″ add a handful of a natural compost starter, alfalfa pellets, or manure, then dampen if needed. Eureka! I actually had alfalfa pellets, left over from a previous attempt to amend my soil. I wasn’t sure if I needed water or not. That chunk of frozen compost would have moisture when it thawed, and the food scraps certainly did. I can’t remember if I added water or not. I continued layering, mindful that I should leave some room at the top and wondering how I would know when I was getting close to the 130 lb. limit. In the end I was chipping food scraps off the compost pile, because although it was a mild day, the compost piles were still pretty frozen and I had used up the most recent food scraps.

Daily rotation is ideal

Children turning the compost pileAt least weekly, rotate the tumbler 2 or 3 times in each direction–daily rotation is even better. Daily rotation was easy to achieve in the beginning; my younger children were eager to turn it . . . too eager. I finally asked them how they were turning it, and they enthusiastically described their method. Using the slats of the adjacent compost bin, they climbed to the top of the tumbler, sat on the lid, and let it tip them to the ground. Then they rotated it the rest of the way around. KIDS, DON’T TRY THIS AT HOME! Once I put an end to that innovative method of turning, rotation was much more erratic, and I have to confess I forgot that I was supposed to turn it a few times in each direction. I thought one tumble in one direction was sufficient.

Don’t pack it too tightly

Check to be sure that the material [is] not packed so tight that it is not mixing when tumbled. If the material can’t move around enough to allow fresh oxygen into the mix, composting will be slower. Here is where I really blew it.

June 28, 2007: contents of tumbler

This is what the contents of the tumbler looked like at the end of June.

I emailed the photo above to Chris, and this is what he said:

That does look fairly done, but it looks like there is a lot of woody material in there and that takes longer to compost. Generally what many do is sift it at this point through a wire mesh or screen to get the finished bits out and then toss the larger unfinished bits back in.

The 14 day thing is really under ideal circumstances, it is never the first batch, because you need to get all the organisms established in living inside the tumbler, but then also weather & sun exposure matters, moisture content, and yes the amount of green to brown stuff.

We had a warm late winter, but a really cold spring, and so the first 6-8 weeks if you started in March probably didn’t do much. Then often people tuck it away in a corner to keep it out of sight, which means it tends to be stuck in the shade, and you really need the sun beating down on that black plastic to make it go really fast.

One thing you may want to try is feeding it a bunch of soft green material like grass clippings, that usually heats mine up pretty good, and it adds a good deal of moisture as well.

Still, the main thing is that even if it isn’t done in 14 days, it is faster than just tossing everything in a pile. Also, you can use it when it isn’t fully done as a top dressing either above or below wood mulch.

Did you fill it up to the top originally? If so then you can readily tell that 50% of it has composted or more (since its looking less than half full now).

It was one of those dry spells where the lawn didn’t need mowing, but I pulled some grass out of my flower beds and threw it in. Of course, it wasn’t chopped up like mowed grass would be, so almost three months later, it still looked like this:

September 23, 2007: contents of tumbler

Almost three months later, the stuff at the top of the tumbler hasn’t changed much. I did just about everything wrong.

I did also sprinkle some water in, but I don’t think it was enough. I also fault my less than ambitious tumbling schedule, and perhaps I packed it too full. In hindsight, I would have been better off sifting it as Chris suggested, and calling the rest of it done. (And gotten this review written almost three months sooner.)

The moment of truth: the tumbler is emptied

When I finally did empty the tumbler on September 23rd, the contents on the top looked like this:

The contents at the top of the tumbler were scarcely rotted at all.

Because I didn’t follow directions, the stuff at the top of the tumbler was scarcely rotted at all.

However, the stuff at the bottom was as composted as I ever get it, and I would have had to wait a whole year for it, sifting it from unfinished compost in the spring:

Image of almost finished compost

The contents at the bottom of the tumbler were as rotted as the compost I would get from traditional methods the following spring. I bet if I had followed the directions more faithfully the whole tumbler would have looked like this.

I learned from my mistakes

I learned a lot from working with the tumbler, and I’m going to try again. I left some of the more finished compost in the bottom, and instead of stockpiling materials, I’m just going to throw things in there until it’s about three-quarters full. As Chris explained,

Stockpiling isn’t really necessary, you can just keep loading it in, but the timer for it to be “done” doesn’t really start until you stop loading and just keep spinning it for like 2 weeks. And again, 2 weeks is under ideal circumstances with the right mix of green & brown.

I think it will actually work better if I stop obsessing and just do it my way.

Chris is a good sport–and a dedicated gardener

One reason why I was willing to review the compost tumbler is because I knew Chris was a dedicated gardener from reading his blog, and so I believed this statement on his website:

We don’t manufacture this tumbler, we didn’t design it. I just went out and researched all the different varieties of tumbler and this is the one I chose, because I honestly believe it is the best compost tumbler you can buy.

And yes, he wanted this review to be published in May, at the height of the season to sell garden products of all kinds. I was determined to give the tumbler a fair trial, even if it took longer. Chris was a good sport about it. He only nagged me once every two months. I thought that was fair. And then I promised I would have the review out before I left on my trip, and I broke my promise. I don’t like to do that, but I had no idea how swamped by travel minutiae I would be prior to leaving. I try not to make promises I can’t keep.

About the Author

Kathy Purdy is a colchicum evangelist, converting unsuspecting gardeners into colchicophiles. She would be delighted to speak to your group about colchicums or other gardening topics. Kathy’s been writing since 4th grade, gardening since high school, and blogging since 2002.

Now, the digging and dividing of perennials, the general autumn cleanup and the planting of spring bulbs are all an act of faith. One carries on before the altar of delayed gratification, until the ground freezes and you can’t do any more other than refill the bird feeder and gaze through the window, waiting for the snow. . . . Meanwhile, it helps to think of yourself as a pear tree or a tulip. You will blossom spectacularly in the spring, but only after the required period of chilling.

~Adrian Higgins in The Washington Post, November 6, 2013

Comments on this entry are closed.

Neil Moran June 20, 2009, 6:58 am

Stopped by to find some information on compost bins for an ebook and booklet I’m writing. I enjoyed the thorough review above and would appreciate any other comments on compost bins for my ebook. My book is a review of garden products for the novice and serious gardener. It aims to help save folks time and money and have more success with their gardens.

Author: North Country Gardening: Simple Secrets to Successful Northern Gardening.

Katie January 16, 2009, 2:45 pm

That is a FANTASTIC tutorial! Thanks for sharing! It will help me make up my mind!

Mary Soderstrom October 30, 2007, 9:04 am

Must add that I had a bad experience with the “compost tea” that collects in the lower part of this composter. I didn’t dilute it and burned my roses. After consulting with a local garden expert–the CBC’s Stuart Robertson–I learned it should be cut 1 part “tea” to 10 parts water. That I did this summer with very good results.


Mary Soderstrom October 29, 2007, 3:47 pm

A closed compost maker is essential if you live in squirrel-invested parts, as I do, only I didn’t realize it for a long time. My husband made me a chicken wire frame for composting when we moved in the house 31 years ago, and each spring I was able to harvest quite a bit to put on my small, city-centre garden (attached house on a 25 by 100 foot lot). But then my two pear trees got big enough to bear well, and I discovered that the squirrels were using all those bruised, windfall fruit I’d chucked on the compost as the salad bar in a fast food restaurant.

Since then I’ve acquired a rolliing composter which works quite well, and which is squirrel-proof. Doesn’t keep them from eating the pears off the tree though. But perhaps there are fewer of them, since the completely free lunch is gone. The composter I use is available several places:,33140

Kymber October 25, 2007, 6:48 pm

Thanks for posting this product review. I’m a first time home owner/gardener/composter and I’m really enthusiastic about getting started on a compost method of some variation.

I’ve been reseraching different gardeners’ methods, and this one seems to make the most sense for me, as a single person living in northeast saskatchewan. (You said it should retain enough heat, even in colder climates)

How can I get my hands on a cheap, small version??

Chris Beasley October 15, 2007, 6:12 pm

Thanks for posting the review, very honest.

By the way, the reason you had that big “nest” of grass at the top IS directly because it wasn’t chopped up. It was basically a tangle of grass and no amount of spinning was going to separate that tangle and mix it in, so it never got the chance to integrate with the rest of the stuff or stay sufficiently moist. I have the same model in my backyard and I put in grass clippings 2 mowings ago and just pulled out mostly finished compost yesterday, it was still a little clumpy, but you couldn’t tell it had once been grass.

Another thing you can try is toss some worms in the composter every once in awhile.

You might have also benefited more from the smaller size, I wanted to be generous to bloggers and give them the larger premium size to use but it is bigger and harder to turn than the smaller size.

Robin October 12, 2007, 11:09 pm

Great review! I’d love to have the Compost Tumbler. I tried regular garbage cans to compost in this year and it hasn’t worked for me. I don’t think I did it correctly though. Maybe some straw and keeping it watered would have helped.

Peter Hoh October 12, 2007, 9:43 am

I’m not sure that composter would be big enough for me. I have two bins, and while I sometimes get a lot of heat from a pile, it’s not sustained. And I’m content to let the stuff break down for a year before I use it.

What I want is a compost finisher, something that would heat up my almost finished compost so that the seeds would germinate. If it could sift out the larger pieces, that would also be nice.

OSoNY October 11, 2007, 11:23 am

This is a handy site for someone from upstate NY trying to garden. This year was a waste for us tho’. A lot ofpeople in this are gave up on their gardens. I would like to link my new blog and my older farm and family blog to yours as it’s a handy one to have and I’d like to share it. Please stop by my blogs sometime. The other one is :

Jessica Madden October 9, 2007, 10:54 am

Wow Kathy, you really gave this tumbler a thorough testing. Congratulations on your excellent, detailed review!


Jane October 9, 2007, 10:16 am

I have a traditional 3 bin system and built new bins last year. It lives out by the alley behind the garage and I generally get finished compost in a year. More turning and additional water would speed things up and discourage mouse nests. I only turned it about twice this year, which was clearly insufficient, but I still had some decent compost at the bottom.

My innovation this year was a rain barrel right beside the bins, collecting water off the garage roof to add into the compost. This means I actually DO add water, because now I don’t have to make the trek from the house rainbarrel or drag the hose over.

Stuart October 8, 2007, 7:45 pm

Have you heard of Colloidal Humus Compost? According to Rod Turner, author of ‘The World’s Best Compost’, it is the best and most natural way to feed plants, with no need for turning or tumblers and no odour. The article is featured on my Gardening SOS Blog.

Carol October 8, 2007, 3:48 pm

I thoroughly enjoyed this review, an honest look at the product and the process, and the results. I could probably not replicate your kids method of turning the tumbler, so I think I’d be safe. I’ve always wanted a compost tumbler…

Carol at May Dreams Gardens

David Perry October 8, 2007, 10:52 am

Kathy, great review! I feel as if I really know something about this tumbler now, and how it might work for a person like myself. The pics and the anecdotal glimpses of your kids’ method of turning it are priceless. Thanks for such a thorough journey…

Mr. McGregor's Daughter October 8, 2007, 8:55 am

Hmmm, a composter that the squirrels can’t get into, which does eventually yield finished compost out of an unbalanced mix of not-very-well-chopped stuff. I might have to put it on my Christmas wish list.

Robin (Bumblebee) October 8, 2007, 8:01 am

Compost DOES happen. It just takes a bit longer if you don’t ease it along with turning and watering during drought.

As for this composter, I don’t believe it could deal with the sheer quantity of organic matter that needs to be composted around here.

–Robin (Bumblebee)

Mel Rimmer October 8, 2007, 7:19 am

I’ve had spuds come up on my compost heap but never anything this bad. A friend of mine once left her Halloween pumpkin on her porch until it rotted down. In the spring the seeds germinated in the heap of rotten pumpkin and the plant went on to take over her whole porch. I can be quite a lazy gardener (and housekeeper) but I thought that was extreme!

Muum October 7, 2007, 9:37 pm

I have the same thing happen with my compost, sometimes I also get walnut trees because the squirrels bury their treasures in the compost pile!