There was a lot of scrap wood in my back yard, so I used what was available (in this case, lots of 2x4s and posts) and built this compost bin to get me started.  I have it about 1/3 full with leaves, grass clippings, and starbucks grounds. Notice I attached spacer 2×4′s in the front so I can add containment as it fills up. I also have constructed a worm pit and some raised garden areas so I can at least get some winter greens going. Stay tuned as I have a lot of pics and plans coming!

As mentioned, there are many sites that discuss the science and “mechanics” of composting so I won’t review everything here. Basically, after the pile has sat for a couple of weeks, anaerobic fermentation will take place in the center of the pile and so it is time to mix things up. As pictured, all that you do is lay down a few bricks (or what have you) as a new foundation and then just start moving the stacks and compost onto the new pile (the top of the existing stack and pile becomes the new bottom etc.). I am pictured here using a shovel but it is only because I couldn’t find my pitch fork. Now having said all of that, if you only have up to four sections, just take one of those hot pokers used for the fireplace, work it down deep, and pull it up to the surface at an angle. In this way you can ”upend” and aerate the pile very easily. They make special tools for this, but the poker worked well for me, and is of course, “cheaper.”

Also, because worm compost (castings etc.) make better soil than tradional compost, I only need to partially break down the pile, because it’s destination is the worm bins. This is because what the worms actually utilize is the bacteria and fungi from the foods that go into their bins. Therefore, we are short cutting this process by hot composting first, and it is easier to just dump your kitchen scraps and other yard wastes into the hot composter than it is to store this stuff until the worms have consumed their existing food etc. In summary, this partially broken down stuff is a more bioavailable form than foods added straight to their bins etc. (and they will love you for it LOL!).  To get to the finished compost, I think that I will just shovel out an area underneath the stack.

Of course, if your intent is to not setup worm composting, then you can just take the compost all the way using the hot method above. How often (and how many times) you will need to move the pile depends on the many factors like temperature, components of the pile, etc. I estimate that I will only need to move this pile this one time before it is “prime” for the worm bins. In this manner, the worms will break down this material into the final “vermipost” and castings in record time. This system of hot composting prior to vermiculure composting is being used very successfully in other countries (India for one).

I thought of this idea because a few years ago I found a ready source for free short pieces of wood (both cypress and pressure treated). That source happens to be the many fence makers found in many cities.  As it turns out, they have stacks of this wood lying around, and they will usually give you all you want if you ask them. Here is a picture of the common “trimmed” pieces that are usually available. They are a couple or so feet long, about 8″ wide, and 3/4″ thick. These are nice pieces of wood and can also be used for many other projects or crafts (I will be posting plans for a “worm tower” made of these soon).

Basically, you just want to take a saw and trim the chamfered ends off and cut all pieces to the same length. Following this, just butt the edges of four pieces together and assemble with exterior screws or nails (I got lazy and used a air brad gun).   The next step is to rip some thinner strips of this same wood (about 2″ wide) that will be used as both a stabilizer for the wood “box” we just assembled, and also will serve as “breathing” seperators for the different layers of compost tower (see pic on right). Note that I have a framing square placed inside the box as I fasten the stabalizers (be sure to get square before fastering etc). Also note that I have painted the outside of the boxes black. I just used cheap exterior black paint and a brush, and the idea was to absorb the maximum heat from the sun in order to spead up the breaking down of compost materials.

Here is the completed bin loaded with compost and “cooking away” in the sun. Note that I made four stackable layers and have set in on bricks.  Also, if the black color is objectionable, I am sure that a dark green or brown would produce similar results without compromising much on solar heating. Of course, you can only use the amount of sections needed to accomodate your compost materials and you just keep stacking sections as it fills. Mix in nitrogen by adding manure or coffee grinds to help heat the pile, and if you are so inclined, add a little diluted urine to really speed it up! This complete project only took me about 2.5 hours! Next time I will be outlining the ease of operation in loading and moving the pile.