Monday, June 15, 2009

Crowson's Low-cost Compost Tumbler

These are the basic directions for building my low-cost Compost Tumbler.

Here are the basic materials you will need:

a) 16 @ 1/2" Lag Screws (a few dollars for all of them),

b) 4 @ Sturdy non-Swivel casters ($2.99 each),

c) a 55 gallon barrel with a sturdy sealable, vented lid ($15),

d) 16 @ coated deck screws 3 - 3.5" long,
e) some scrap wood (2 pieces at least 2' long and 2 at least 3' long, preferably pressure treated).

Step 1
Cut two of your scrap 2x4s 2' long.
For the other two, the two that will be sitting on the ground, I recommend treated lumber; I used some treated 2x10s that I had left over from building some steps. You will need to cut these two boards about as long as your barrel is tall (In my case these boards were around 36" long so I just left them that length).

Step 2
You will need to decide, based on your barrel diameter a proper spacing for how to affix the support boards to the base boards. Assuming your 55 gallon barrel is about the same size as mine, I set the two support boards 3.5" from the ends of the baseboards and about half way from the sides (5 or 6"). Then you use your deck screws and fasten the boards together squarely. I used a speed square (the orange thing in the picture above) to make sure all my cuts and placements were kept square.

Step 3
You will need a ratchet and drill bit or a socket drill bit for installing the casters. Assuming your barrel is about the same size as mine, you should place the casters centered on the support boards about 3.5" from the ends of the boards with your wheels parallel with the support boards. If you don't have the socket drill bit then you will need to take a pencil and mark where to drill pilot holes for the lag screws because they can be hard to start if you don't have a hole going already (you might want to do this even if you have the drill bit since it does make it easier). Tighten down all your screws and make sure all your wheels are in line.

Step 4
Your tumbler base should look like an upside down dolly, and it is pretty much done. Put the base on level ground wherever you want to keep your new compost tumbler and put your barrel on top evenly spaced on the wheels. Give it a whirl!

One thing to account for is that if you don't want to have to set your barrel up straight to take the lid off and put compost in then you might want to figure out a good way of making a little door on the side in between the wheels. I didn't do this because I don't mind sitting the barrel upright and filling it with materials then putting it back on the stand. I realize that some people might have a hard time moving the barrel around, especially when it is heavy with compost materials, and in that situation I guess you'd need a door or something on the side...

One of the good things about mine is that I can take the barrel off the stand and roll it across the yard to wherever I want to put the compost without having to scoop it out into a wheelbarrow first and then scoop it out again. Also an important thing to mention is that AIR is a key component in making compost so you need to vent your tumbler somehow. My barrel has two screw on caps in the lid and I just removed the smaller of the two. After turning it a number of times there was no noticeable leak of compost from the hole...

I realize that the design is fairly simple, but that is one of the good things about it; building it took less than an hour including the time it took to get everything together and take pictures.

And there you have it! The simple Crowson Compost Tumbler; built for about $30. Planet natural sells a little fancier version for only $285 if you would prefer... Or Clean Air Gardening has one with a few less features than that one for $149.

Mother Earth News even did a test article about the various compost tumblers for sale and whether or not they were worth the hassle (and price tag). Seems they pretty much make compost at the same rate as a well-managed compost pile. The reason tumblers seem to work better is because we gardeners are more likely to turn them than we are to get out and turn the compost pile. They also say that you should make sure you add plenty of browns to the tumbler because if you get too many greens in there you might end up with a "slimy mess"...

I know how likely I am to get out and turn a compost pile (unlikely) so I think this is the way to go for me. One good way to do it would be to have a barrel sitting upright that you add fresh stuff to and one on the tumbler that is mostly full and composting. When one is done you switch them out, use the compost, and start all over again.

I hope this helps somebody out there, and that somebody tries it. Good luck!


  1. Haha! You are so clever.
    It looks like you had a good helper.

  2. That's an ingenious design, Jason. People always seem to be wowed by bells and whistles, but the simplest solution to a problem is usually best.

    Personally, I don't turn my pile, just let it rot a long time while I build a new pile. :)

    Sorry to hear about your goat. It isn't fun being the one to decide when to resort to culling.


  3. Anonymous6:09 PM CST

    We've had an upright compost bin, but thought this was an excellent idea.

    Since we had a plastic barrell already, John filled it up the next day. He hasn't got the roller platform done yet, but is rolling it back and forth in the yard.

    Romona (2nd cousin in Australia, Remember?)

  4. Anonymous12:50 AM CDT

    There is one thing you can add to this if you are using a steel barrel. We put two rows of 6 inch x 1/4 inch zinc plated bolts thru the sides of the barrel. They are placed about 6 inches apart in two rows on opposide sides. This helps to break-up and stir the contents. For more support of these bolt/spike "agitators", brace the bolts with a 1x4 strip on the inside of the barrel. Just make sure you don't have the bolt heads in the path of the caster wheels.

  5. Anonymous12:09 AM CST

    Several questions.

    1. When your barrel is full of material, about how much does it weigh?

    2. When your barrel is full of material, is it difficult to spin / rotate / turn?

    3. Please give details about the casters:
    a. what diameter?
    b. what width?
    c. galvanized?
    d. manufacturer / supplier?

    All other horizontal tumblers I've seen on the web have little bitty casters which I think are inferior to these big casters you use.

    (My barrel is thin-walled -- a used pickle barrel -- and I believe using the wrong size casters will ultimately damage / wear it out.)

    If you had to do it all over, would you use these same casters, or try to get even larger casters -- or perhaps wheels (the lawn-mower type, which only cost about $5)??

  6. Honestly it is pretty heavy when full, and as such i wouldn't recommend filling it over half-way or so. when i fill one of these barrels with grain for feed they weight around 350 pounds. they hold up to beating and dropping and rolling even when full of grain, so they are pretty dang sturdy. I picked the castors up at a Harbor Freight store, and would have to go out and measure them for exact size. The barrel I used was a feed storage type barrel that could have had olive oil or something in it, but not sure honestly. They are pretty thick though; thicker than the terra cotta barrel i bought recently that for sure had olives in it. I am super cheap. If I had to do it over again I'd probably do it similar, but one problem i encountered with this setup is after you tumble it and stand it up to sit for a while you have to leave the caps off the lid so it can breath a little, and if you have it sitting out next to a shed or something it will collect rain water and screw up the compost making more of a tea that is hard to pour out of such a big barrel. I would recommend storing it under a shed roof or setting some kind of lid over it that wouldnt obstruct the holes from breathing.

    as it is now i rarely use the compost tumbler since I throw any waste i have to my pigs, and just disc in any organic material I have to the garden plot if the animals can't use it. if you don't have pigs though I think this is a decent setup if you get a few extra barrels so you can rotate them often without having to fill them all the way up.

    and thanks for the questions. lawn mower wheels would probably work better, but they cost more, so if you don't mind springing for the little extra I'd give it a try as long as they are not made out of plastic or something. check out a harbor freight if you have one within driving distance, they have all kinds of useful stuff for much cheaper than standard hardware stores. some times you get what you pay for there, but most of the time their stuff is pretty good. i recommend their pneumatic nails and staples, but not the pneumatic nailers themselves. they might work well if taken care of diligently, but the one I had from there had been somewhat neglected and worked like crap. finally just junked it. their pneumatic hoses are good and a good deal too.

    one other improvement might be to raise the base up on a couple of concrete blocks if you have them and have a good semi-permanent spot to sit it. it would probably make it easier to use. if you have a barrel similar to mine you could add water and let it sit for a while then put the lid on and spin it a little and add the caps back to block the air flow and set it back on the stand, unscrew a cap and have a little compost tea dispenser...

    just some thoughts. :)


Thanks for taking the time to comment! I really appreciate the input and will do my best to respond quickly if need be. Thanks again for reading!

Yours Truly,
The Crowsons