April 7th, 2009
Organic Compost Tumbler

compost tumbler
The finished product from the Organic Compost Tumbler: sifted and unsifted compost.

Chris from Organic Compost Tumbler sent me a UCT-9 compost tumbler to review.

April 3, 2009: The Results

About 2 1/2 months has passed since I loaded up the “World’s Best” Organic Compost Tumbler. At first the material in the tumbler was quite light and the tumbler was easy to turn. In the last couple of weeks, the material has become denser, reduced in mass to just the bottom half of the tumbler and so the tumbler has become more awkward to turn. I took these as signs that the compost was ready.

When I looked inside it looked very similar to my own open-pile compost. There were still some sticks in it but the oak leaves, kitchen scraps, and pine needles had broken down.
compost tumbler
In the case of compost tumblers, half empty is definitely half full.

I decided that the compost was ready. If I waited for the big sticks to break down that the other smaller stuff would rot away to almost nothing. Also, I needed compost for my vegetable garden and I needed the compost tumbler for all the trimmings from the spring garden cleanup.

My first question was how do I get the compost out? I wanted to dump it into a wheel barrow or bucket, not just on the ground but it’s impossible to put anything under the compost tumbler and turn the stuff out. I ended up dumping it on the ground but now I realized that if I’d found some plastic sheeting, that would have solved my problem.
compost tumbler
The compost filled the bottom half of the tumbler or two of these galvanized tubs…sorry that I don’t have a better way to measure the amount.

The compost apparently had not heated up as much as was expecting because avocado and mango pits had not broken down (and some were sprouting), nor did section of Turk’s cap stems (which I had cut into 3 to 4 inch pieces). However, there was no evidence of smaller seeds or garlic sprouting–which I have a problem with in my open pile. I do not interpret this as a fault of the Organic Compost Tumbler because (see below) successful composting depends a great deal on the mix of materials. Although I had chopped the larger pieces down and turned the tumbler almost every day, the mix was a bit on the brown side and initially too dry.

compost tumbler
A mix of fine compost and some larger chunks that I think need to break down more.

The result, then, was very similar to what I get out of my open compost pile–with one important exception. It wasn’t crawling with roaches, pill bugs, or earwigs. This made sifting it so much more pleasant. I use the fine compost on my vegetables when planting them or as top-dressing. I use the coarse compost as a mulch or throw it back on the pile as “starter” for the next batch.

Bottom Line

Do I like the Organic Compost Tumbler?
Yes. I don’t think the end product is much different than my open pile. But making the compost is a much more convenient. It’s so much easier to tumble the composter than it is to turn an open pile. And it looks nicer and it doesn’t attract pests (not only roaches, earwigs, and pillbugs but raccoons, rats, and opossums.)

Would I recommend it?
Yes. I think a compost tumbler is useful for people in urban or suburban neighborhoods who don’t have room or which there are restrictions on compost piles. It won’t produce all the compost you need nor will it be able to consume all the kitchen scraps and garden clippings that you produce. But it is a start.

Since receiving the Organic Compost Tumbler for review I’ve kept an eye out for other types. The prices are about the same but this is the sturdiest one I’ve seen. And it’s made out of recycled plastic.

Would I buy it myself?
I am considering buying one or two more…as budget permits. One is simply not enough to handle my composting needs. I used up the entire contents of my first batch in about two hours and wanted more. I have already filled the compost tumbler up: this time with chinaberry and hackberry tree sprouts. I’m looking forward to seeing whether a different mix will compost hotter and faster. I’ve learned my lesson about making sure it is damp (but not too wet). And I will probably “harvest” the mix as soon as the tumbler feels heavy and awkward to turn.

The original post, written January 19, 2009 when we put together the compost tumbler, is below.

The Problems with Composting

I don’t have to be convinced of the benefits of composting. I’ve always done it although not in any focused or scientific way. I have an open pile out back and throw kitchen (plant) waste and leaves and garden trimmings on it. When it gets to certain height, I turn it over. Usually there is some composted material at the bottom of the pile which I sift, throwing the larger pieces back on the pile.

So you’d be right if you guessed I’m predisposed to like a compost tumbler–not because someone sent me one to try but because I already love composting and recognize my current approach is inefficient.

These are the problems I’m hoping a compost tumbler will solve.

  • My compost pile never heats up properly. I learned long ago not to put any weed seed in it.
  • In the humid south, compost breaks down quickly. On the plus side this means my pile breaks down pretty quickly; it also means that compost added to the garden disappears quickly and constantly needs to be replenished. I never have enough compost. (Does anyone?) I’d like more compost faster.
  • An open pile attracts pests. Faithful readers already know about my raccoons, possums, and armadillos. I’ve never seen rats (although everyone in Austin apparently has rats–maybe my open compost pile is why my yard is a cat magnet). There is a feast of cockroaches, beetles and grubs at the bottom of the compost pile. I could live without them but they keep the lizards fat and happy.
  • My open compost pile is a pain to turn. Not only have I permanently injured my right shoulder from turning the pile over with a pitch fork, but I suspect that one reason I caught pneumonia 7 years ago was from mold spores or other microbes I inhaled when turning and sifting a pile.

compost tumbler
An open compost pile is an eyesore!

Other problems with an open compost pile that you might have:

  • smell: If a compost pile is too wet, or if it has too high a percentage of green (nitrogen) material in it, it will become anaerobic and smell ammoniacal (like stale urine). It’s so dry in Austin and I have such a high percentage of brown (carbon) material in my pile that smell is not a big problem for me.
  • eyesore: A pile of rot is not always viewed with the same ecstacy by non-gardeners. Even garden designers might interpret an open compost pile as a problem spot.
  • neighbors: In certain towns or communities, open compost piles are banned. See above: pests, smell, eyesores.

Setting up the Compost Tumbler

The hardest thing about setting up the compost tumbler was finding a flat surface on our sloping lot. It tumbles. It’s heavy. A flat surface for stability is a must.

Setting up the compost tumbler was straightforward. The barrel itself came in two pieces so even I (a 52-year old, non-athletic woman) was able to lift it and assemble it. However, AJM was kind enough to help. Bottom line: I could have put it together completely on my own but it was much easier with help.

compost tumbler
The trickiest part of the assembly was putting together the stand. I could have done it alone but I was happier taking photographs of AJM doing all the work.

Filling the Compost Tumbler

Pages of instructions came with the compost tumbler explaining how to figure the right mix of green to brown material. I read over it and then did what I always do. I used the materials I had on hand. I didn’t measure anything. I did try to keep a balance in mind; that is, I did a little brown, then a little green. I didn’t pack in the material.

Here’s what went in: one pail of vegetative kitchen scraps (potato and onion peels, fruit rinds and cores, coffee grounds); brown oak leaves; fresh pine needles; green softwood stems of perennials that need cutting back (mostly Turk’s cap and just frozen basil and pepper plants); and semi-hardwood stems (oregano, ruellia). I cut up the stem of plants to about 4-inch lengths–which is what I do anyway for my open compost pile. I also put in a shovel-full of almost finished compost from my old pile as a “starter”.

The UCT-9 is the larger model and has a capacity of 9.5 cubic feet. Even so, I filled it up quickly and looking around my garden immediately thought, “Hmmm. I could easily fill half a dozen of these.”


compost tumbler
The hole-punched tube is supposed to bring oxygen into the mix so that the contents will break down more effectively.

There’s certainly nothing rickety about this compost tumbler. It’s made entirely of heavy plastic. The parts snapped together; there’s no metal anywhere. The plastic is recycled (a big plus in my book) and the compost tumbler is manufactured in the USA. Overall, it is sturdy and stable and I don’t have any uneasiness that it might break away or fall on me while I’m turning it.

I’ve read elsewhere that some people find it hard to turn the compost tumbler. I’m amazed how easy it is. It’s sort of like pushing someone on a swing. With each gentle push, momentum takes it further.

I’m definitely not the strongest, youngest, or most athletic person in our family but I didn’t have any problem tumbling the compost.At this point, the contents are fairly dry and light. If they were too green, too wet, or too packed in, they’d be heavier and more difficult to turn.

After my first batch of compost has “cooked”, I’ll update this post and let you know what happened. Never known for my patience, I’m already waiting with bated breath. How long will it take? Chris says,

One thing I always stress in regards to speed is that composting is an inexact science, and speed of the process depends on
1. Oxygen
2. Heat
3. Moisture
4. Surface area of compostables
5. Mix of compostables.

I think my mix is good except that it might be a little dry. I’m going to go check it right now and see if it needs to be moistened. It’s quite warm in Austin (it’ll be in the sunny 70s all week).

by M Sinclair Stevens

22 Responses to post “Organic Compost Tumbler”

  1. From Rachel from Austin:

    Very nice, MSS! I look forward to seeing how your new tumbler works. I keep thinking I should get one for myself, given the universal composting challenges that you delineate so clearly above.

  2. From Mary Beth:

    I have been lusting after a compost tumbler – and an end to turning the pile, which can be tough in a square plastic bin. Can’t wait to hear how long it takes to cook up a batch. Keep us posted!

  3. From Dee/reddirtramblings:

    This was wonderfully helpful. I’ve always wanted a tumbler, but haven’t done so yet. I’d like to own one myself, and your review set me straight on a few questions I had. Thanks.~~Dee

    If you have any other specific questions, let me know. Austin garden bloggers, if you want to give it a whirl, give me a call and come for a visit. — mss

  4. From Diana - Austin:

    That’s cool, MSS. I had an unsuccessful composting experience before and have been reluctant to try again. Seems like your tumbler there might be a good answer. I’ll keep up with your progress and see how it goes. P.S. I thought we couldn’t put oak leaves in our piles becuase they don’t break down for, say, about 10 years or something outrageous?! Thought I’d heard that somewhere. Let me know.

    Live oak leaves break down very slowly. Mine are red oak and other large-leaved variety. (You can see them on the ground in the photos.) They break down more slowly than cedar elm leaves but within a few months even on my open compost pile. Generally, I grind them up with the mulching mower and just leave them in the beds. — mss

  5. From Bonnie:

    I had a tumbler but didn’t like it because it is hard to keep the pile moist. Maybe I need to give it another try. I thought about switching to an open air composting container so rain water (what little we get) would add moisture or I at least wouldn’t have to screw off a top to spray it.

    What did you do with your old tumbler? If you still have it but someday decide you don’t want it, give me a head’s up. — mss

  6. From Carol, May Dreams Gardens:

    I also reviewed a compost tumbler, the smaller size, and was very happy with the results. I have noticed that here in the winter, I don’t think it is heating up all that much, and I’m not as likely to go out in the cold to turn it. I’m just going to sit tight until spring and then go out and see what’s happened. I could also use more tumblers; even with the compost tumbler, I have three 3 x 3 wire bins full, too.

    Very helpful information!

  7. From Gail:

    I’ve been eyeing one of these tumblers for a while. If it makes compost quickly and turns out to be easy to use…I might let myself get one. All eyes are on this experiment MSS. gail

  8. From Lori, Austin TX:

    I’ll be waiting for the results of your compost tumbler with bated breath. This whole battle with the ROUS in my backyard probably started because I’d throw coffee grounds and old fruit cores on the top of the flower bed since I don’t have room for a compost pile per se. The Natural Gardener carries more compost tumblers these days, but the one that looks easiest to use, the Tumbleweed, has a stand that doesn’t look sturdy enough to be durable. Yours looks like it might have solved that problem.

    The next time you come over, come on back and give it a tumble to see whether you think it is more sturdy and stable than the models at the Natural Gardener. — mss

  9. From Pam/Digging:

    I’ll be watching with interest. We just removed a large, open compost pile in our new yard, which was unsightly to us. It was composed mostly of live oak leaves, and only at the very bottom had they broken down. (What in the heck are you supposed to do with all the live oak leaves if you garden beneath?) I might be willing to try a tumbler, which has a tidy look.

    The live oak leaves probably didn’t break down this year because it’s been so dry. The fact that they are slow to break down makes them a more useful mulch than compost ingredient. Try this. Mow over them with a mulching mower. Wet down perennial beds and then add the ground up live oak leaves. Wet those down and cover with decorative mulch to keep them from blowing away and to look tidier. You can really reduce the amount of decorative mulch you need to buy if you put the live oak leaves underneath it. — mss

  10. From ESP, Austin:

    Hi MSS.
    I have one tumbler and one rotary composter on a base. Both have worked extremily well for me over the last seven years. The rotary one, although being harder to rotate is fantastic as it catches all the “juices” as the “goodness” breaks down in a catch tank that it sits on. In the tumbler bin all this goodness just drains out onto the surrounding ground. I bet the ground below it is now amazing though. It is amazing how much compost tea I get out of that catch bin each year. I am interested to hear how you like your tumbler. I bet you will get another, one is just never enough!!

    This model comes with an optional catch tray to catch the “juices”. I don’t have that option piece to test but also, at this point, no juices. Maybe my mix is too dry. — mss

  11. From Cindy, MCOK:

    Ever since Carol of May Dreams Gardens posted about her tumbler, I’ve been coveting one of my own. I’ll hold myself back until I hear your review of the compost itself, though. It sounds promising!

  12. From Jenny Austin:

    Lucky you! Can’t wit to hear of your success and then I might be tempted.D built compost bins for me and they are piled over the top with dry stuff. It is just too much effort to water the pile so I just keep piling it in there. Someone was talking the other day about worm composting. I wouldn’t mind giving that a try for the stuff from the kitchen.

  13. From Jan:

    This looks interesting. I’ll be waiting to read how it turns out, and if it is worth the expense. I have two wire bins for composting that works fine, but this would be easier.

    Always Growing

  14. From Robin Wedewer:

    I was fascinated to read this because I have many of the same problems composting that you described. Although I have 3 biostack compost bins, they always seem to get “fuller” and I haven’t coordinated a proper system to finish the compost. I have been contemplating a tumbler just for this reason.

    I’ll be looking forward to your follow-up. The tumbler you’re trying looks like a good-sized hefty one. Boy do I need a big one!

    Robin Wedewer

  15. From angelina:

    Hey! Is that the first time you’ve ever posted a picture of yourself on your blog?

    I am interested to see the results on this one. This kind always seemed the most promising to me. I am going to have to do my composting the traditional way for now as there’s no room in the budget for these. But maybe if your results are good I’ll save up for next year!

    No, it’s not the first photo I’ve posted…but I don’t do it very often. — mss

  16. From Steve Mudge(Fort Worth):

    We have a compost pile the size of an SUV so while the tumbler looks like a great solution its just too small for our needs…right now its just an open pile but I’m going to try making a couple 6 foot tall wire towers to contain it.
    One thing that is enjoyable about turning a compost pile by hand is that you can see what plants you grew the year before and on cold January days its kind of nice to reminisce about the Okra and Peppers…(“think roses in December”…)

  17. From Doug Green:

    I reviewed one of those last summer with mixed results – but mostly my fault as I was trying to turn it into a continuous composting process rather than a batch process. And yes, when you keep filling it, it gets heavy. But the trick is to get the right proportions and stop filling when it starts to work away. Both things I obviously will have to do better at this year (call it a learning curve).

    I read your review with interest. Progress seems a bit slow here but I think the mix was too dry. I’ve added leftover tea and coffee and it seems to be breaking down better now. My mix might have had too much brown matter, too. As you say, experimentation is the key. — mss

  18. From Jenn:

    Keep us posted on your progress with the tumbler.

    I’ve one of this model – it brags of 100% recycled material, yes?

    But I’m such a lackadasical gardener these days that I’ve not done anything with whatever is in there.

    And I’ve 5 gallon bins of ‘wet’ and bunches of dry to start up the next batch. Maybe this is telling me I need to do this tomorrow.

    After I scuffle hoe the dang weeds in the gravel. My neighbors must think I’m nuts, out there scratching in the gravel every weekend. They simply hiring the day laborers to come in once a month and poison everything away. I think THEY are crazy.

  19. From our friend Ben in Pennsylvania:

    Loved this post, MSS! Last year, a friend gave us a really nice compost tumbler, but we have a three-bin pallet compost system so we haven’t gotten around to using the tumbler yet. I’m astounded that any compost system will break down avocado and mango seeds, though! I don’t suppose they’d grow for you if you just planted them?! And oh dear, composting garlic cloves. I’d be planting those out for sure!

    My husband is the cook so I can’t always monitor what goes in the compost pail. However, I do plant any wizened garlic cloves that he decides aren’t nice enough to cook with. As for the mango and avocado pits, I have sometimes planted those that sprouted but–despite Austin’s scorching summers–it’s just too cold here for them to grow outside. — mss

  20. From mga, Austin:

    I’ve had a Tumblebug for several years — a 20-sided thing that looks like a mine. The bolts that hold it together are extra long and extend a few inches into the compost to help chop it up. You’re supposed to roll it around regularly but it requires some space, and if you don’t leave it in a different place every single day it kills the grass. Other than that, it sounds like your experience — it gets hard to roll when the compost is progressing, it’s hard to get the compost out, and some stuff never breaks down. The door cover has cracked, now, and apparently the company (or the guy) has gone out of business, so I can’t get a replacement. Right now it mainly serves as a winter cat bed for the neighborhood cats. We also have an ordinary compost heap but I guess I don’t do enough with it because every time I want some compost the oak tree has filled it with a tangle of threadlike roots. I would LOVE to have a stationary, off-the-ground, tumbling composter!

  21. From Jenny Austin:

    It’s nice to read about how these tumblers work but Im afraid it would not be able to cope with what I produce in my garden. We had a shredder for some years but it was a rotten job. A combination of both would probably brings faster results. Maybe when I have a smaller garden.

    Oh! MSS Where the heck are those gloves or are you saving them for very special occasions?

    Yes. I was going to make a remark about my missing gloves. As you can see, my nails are “gardener’s nails”. I do wear them. Sometimes. When I remember. — mss

  22. From Anne Roanoke,VA:

    I have the large model of tumbler displayed. Unfortunately, I didn’t have help putting it together but got the job done without problems. I use my compost for square foot gardening and it works pretty good. I had an abundant crop last year but it’s been extremely hot & dry this year. I don’t have a problem with enough moisture, I think the heat and plastic takes care of that and it sure is easier to turn then using a pitchfork and fighting bees. I’ve moved the tumbler twice trying to find the best place for it and a more level spot. Oh yeah, I definately use gloves when working in the garden.