Sunday, November 1, 2015

Compost Cage

As I've discussed elsewhere, composting is the process of speed-rotting organic material to make the perfect garden nourishment. And while you can follow formulas and build lidded wooden bins and fuss and fret over your compost, the truth is that it's very hard to screw up. Still, even with a regular-old rotpile, you'll probably need to turn it on occasion if you have lots of grass clippings.*  The compost cage eliminates even that little bit of work.

My compost cage is made of:
One 20' x 6' section of chicken fencing 
One fence post

Drive the fence post in the ground, zip tie one end of the fence to the post, then attach the other end of the fence to the first end by wrapping the loose end wires around it**.  What you end up with is a round, vertical 'cage' about 6' tall and 4' across.

I set mine up last spring and put exactly two ingredients into it, grass clippings and shredded paper. Both can be problematic, because when wet they tend to pack, making an oxygen-proof mat that can force a slower, anaerobic rot in your pile.  But the tall, slender cage keeps the whole inside oxygenated without mixing. 

The clippings I just raked up from around the cage after mowing and tossed them in. It takes surprisingly little to fill 6' of cage.  It does settle pretty quickly, so there's room for more every time you mow.

The shredded paper took a little preparation.  I shred everything I can: newspapers, junk mail other than the little plastic envelope windows, Taco Bell boxes.  Once I get a 5-gallon bucket-full, I fill it up with water and let the mix soak overnight. The water gets soaked up by the paper, which helps break down the fibers. It also helps the pile stay moist.  I don't add any other water to the pile.

All through the summer, the cage looked like a greenish-brown pillar at the back of the yard. It was even taken over for a month or so by red-flowered trumpet vines. But worms and rolly-pollys were working the whole time.  When I removed the cage this morning and knocked it over I got about 20 cubic feet of compost, enough to fill one brand new 4'x4' bed and to cover the 4'x10' bed I'll be planting with garlic this week. What you see in the picture is all that had not rotted, plus a new bucket of paper.

The compost cage is a slow-rot, also known as "cold composting." It's not going to steam in winter.  It's not going to drop noticeably over the course of a few days. But if you have lots of materials and lots of time to wait for them it's the easiest way to get wheelbarrow loads of good compost with almost no work at all.

* Composting works best when you have a mix of "browns" (like leaves) for carbon and "greens" (like grass clippings) for nitrogen. One problem you might face is that it's hard to have both at the same time.
** You could use zipties here, but I don't because I want it easy to disassemble.


  1. I pick a spot in my garden and dig a deep hole. The current one, taking all the fall leaves, is a 4-foot cube. Everything goes in there. I toss a layer of material in, stomp it down, put a cap of dirt on top about an inch deep, then keep adding layers until it gets to level ground, and I mound a thicker layer on top.
    I don't worry about it past that. If it is spring or summer, I plant right into that last layer. The soil here is really poor, heavy clay, and it needs organic matter down deep. All the fireplace ash, kitchen scraps, paper and everything goes in. It's all gone by the next time I dig it up.
    In late fall I dig a big one, and all winter kitchen waste goes in. As soon as it thaws, I put the dirt cap on and plant over it.

  2. Have you ever had problems related to too much fireplace ash in one place? I haven't, except the occasional time that I'll burn up a whole compost pile because the coals weren't dead. But some folks swear it off. Thoughts?

  3. Not that I have noticed. I suppose it could make your soil too alkaline. This summer I burned my stick pile, it was about 8 feet high, mostly brush and raspberry canes. After a few months I scattered lettuce seeds all over the ashes and now have a great late-season lettuce patch.
    I think it is an overblown fear.
    I burn for a few hours every night all winter long, so it is quite a lot of ashes, but it is mixed with a lot of other stuff.