Sunday, August 24, 2008

Compost Bin-anza!

As you RFC readers may know, I have been maintaining a small garden in the median of the road where I live. Now, as I am starting to think about the end of growing season '08, I have begun to make plans for garden expansions and forays into sustainability. I want to go beyond growing a few vegetables to throw in with dinner or salads. I decided the next step was to start making my own compost for use in future garden beds. Composting is a great way of 'greening' your day-to-day life, since kitchen waste can be used to feed the soil. It also helps you to close your system of food production and consumption by eliminating the need to bring in soil amendments from external sources.

Since I was also interested in learning more about woodworking, I decided to build a three-section compost bin, which allows for a high degree of productivity (you can have multiple piles going at once) and involves some detailed woodcutting and mathematical planning. RFC friend and neighbor Ron Wood volunteered his backyard for the ultimate location of the composter, and helped me find plans for the design. You can check out the plan we used here.

We set aside a free weekend and headed out to Lowe's. The plans for the composter told us what materials we needed. We decided to modify the design a bit and abandoned the idea of creating a top. Most people, it seems, are able to successfully create compost without covering it. My dad, always helpful, assisted in math calculations and also cut the wood for us. We assembled some parts of the bin with his help, then took everything home, where we would do most of the major construction. Other materials we used besides wood included 'hardware cloth' -- the wire mesh for the sides -- paint and decking screws.

Ron cleared out a likely corner of his yard in preparation, and we started the next step: painting. We were told to use untreated wood, because having chemicals up against your compost is unwise and potentially dangerous since you'll ultimately be spreading it on the ground where you're growing food. So, instead, we had to paint, which seals off the wood and prevents it from rotting as it weathers. Yes, paint also has its share of toxic chemicals, so there's no ideal solution here for preserving wood.

After painting (two coats!) we began putting together the bin. I confess we became a bit lax about taking pictures at this point, because we were focused on finishing. We assembled the 'sides' of the bin first, then attached them to long runners, creating the sectional structure you see in the picture below.

A key aspect of this compost bin is the slatted front -- you can gradually slide slats of wood along guides we built along the front as you build up a bigger and bigger pile of compost.

Making the slats fit right was by far the hardest part of building this composter. When we were almost finished putting it together, it turned out we had made an error when we attached one of the sides. One section was too wide for the slats and one was too narrow. We did some taking-apart and putting-back-together and ended up having to cut .25 inches off most of the slats before we could slide them in. A caution to those who attempt this project: make sure the slats fit before you attach the sides to the crosspieces!

At last, it was time to begin building our compost pile. We laid down a layer of sticks for good air flow at the bottom of the pile.

Then I forked in a good amount of 'mature' compost: old leaves and dried out grass clippings. Ron has a good pile of leaves to draw on in his backyard. Our reference book (How to Grow More Vegetables by John Jeavons) recommended that the pile be composed of 45% mature compost (organic matter further along in the process of decomposition like fallen leaves or straw), 45% immature compost (green matter like fresh grass clippings or pulled weeds) and 10% soil (which already contains some of the microbes you're trying to encourage as you make the pile).

Next I added some bamboo clippings and weeds -- green or 'immature' material.

We created a soil mixture using good compost and some topsoil from elsewhere in the yard and sprinkled it on the top.

The last step: watering! Now it's time to let the compost cook. My dad keeps a big thermometer in his pile so he can track the temperature. You want your compost to get as hot as possible, because this means the compost process is working. We plan to add small layers of kitchen waste and dead leaves as needed, then create another big section of brown, green and soil when we have enough green material to do so. I think the hardest part of building lots of compost is finding enough green. Grass clippings could be great for this.

I highly recommend How to Grow More Vegetables as a reference if you're interested in getting into composting. Jeavons explains how composting works and why you should be doing it in your own backyard. Also, check out for lots of good online info about composting. You don't have to go to the extremes we did to create a compost pile. Just build something that works for you, and go from there. In my opinion, there is no excuse not to compost. Once the pile is set up, maintenance requires only a little time. The results afford huge benefits to the environment, building healthy soil from food and yard refuse that might have gone to waste. Also, we all know industrial agriculture is essentially murdering the soil at an incredible rate, using pesticides and fertilizer that deplete soil health and neglecting to rotate crops. I believe we should do what we can to make new, fresh soil and give back to the earth what we have taken as we grow food to keep ourselves alive.

As an aside, if you would like advice on building the compost bin design we used, feel free to shoot the RFC an email. And don't forget, big gardening and sustainability plans are in the works, so check back soon for more updates!

1 comment:

  1. nice post, i'm gonna build one this weekend too!