By Cat DiStasio
Composting food scraps from your kitchen is an easy way to reduce landfill waste and create nutrient-rich potting soil for your garden. You probably already knew that. Did you also know you can build your own composter for the cost of a movie ticket and less than 30 minutes of your time?
There are many, many different types of composters available for sale at hardware stores and garden markets (and online, of course), but they are often quite expensive. While there’s nothing wrong with buying one if that’s your jam, making your own is just so easy, cheap, and fast. It’s tough to come up with a reason not to build your own.
Using an inexpensive plastic trash can and supplies you may already have on hand, you can easily build your own composter. Some commercial tumbler-style composters sit horizontally, often on a large metal frame, and can be turned with a crank handle. This DIY version uses the same principles, but is designed to sit upright – which takes up less garden square footage and makes it easier to add scraps. You’ll be able to turn your round trash can on its side and roll it on the ground to mix the contents, replicating the handle-driven turning of a tumbler composter.
Here’s what you’ll need to begin. As you’ll see, it isn’t much.
- 1 round 32-gallon plastic trash can with a tight-fitting lid
- Drill and 1-inch spade bit
- 3-4 bricks or cinder blocks
- Organic refuse (uncooked kitchen scraps, leaves, grass clippings, undyed paper)
- 2 bungee cords (optional, but recommended)
A note on trash cans: You can repurpose an old or damaged trash can, if you have one around, but you’ll have to scrub it very clean first to remove all traces of inorganic materials. A new plastic trash can of this style (lid included) typically runs around $10, though. If you prefer, consider spending a little more for a wheeled trash can, which may be easier for some people to tip on its side for turning.
1. Drill air holes.
In order to decompose properly, organic material needs some oxygen to help the process along. This is why commercial composters have ventilation, and why many compost bins are slatted or perforated. To create a similar effect on your DIY composter, use a 1-inch spade bit to drill holes all around the walls of the trash can.
It’s best to create several vertical lines of holes, with 6 inches between each hole. Space the lines 6-8 inches apart so you do not compromise the structural integrity of the trash can. Drill several holes in the bottom of the trash can as well.
2. Add food and yard waste scraps.
To use your new composter, set your composter atop the cinder blocks to allow for drainage. Place equal amounts of brown and green materials in the trash can and mix them together. Green materials include vegetable and fruit scraps, egg shells, grass clippings, and used coffee grounds. Examples of brown materials would be dead leaves, twigs, newspaper, sawdust, and cardboard. For best results, keep composting materials damp—like a wrung-out sponge—but not wet or dripping. Typically, the moisture in your green scraps will be plenty, but if you live in a very dry climate, you may need to spray it with a bit of water as well.
Do not put cooked food, oil, meat, or pet waste in your composter, nor anything treated with pesticides.
You can add refuse to the bin whenever you like (because nobody really loves a full scrap bin in their kitchen!) but be sure the close the lid tightly after adding new materials, and use the bungee cords to keep it closed. This will protect against scavenging critters, like raccoons and rats, who can be deluded into thinking a composter is a breakfast buffet.
3. Turn your compost regularly.
At least once a week and always after adding new scraps, turn your composter by laying it on its side on the ground and rolling it around several times. This will mix up the contents and make for a more efficient composting process.
In most climates, it takes between two and four months to turn scraps into usable compost. Many people are concerned about how a compost bin might smell. The good news is that, done correctly, composting should smell more like fresh dirt than like a back alley dumpster. If an unpleasant aroma develops, there is a chance your ratio of brown to green materials is off, or the compost mixture is either too wet or too dry. Although it may take a little troubleshooting to find the sweet spot for your area, rest assured, it will be a worthwhile effort.
Be sure to check in with us regularly for more composting tips! We’ll be sharing an article soon about how to transform an old nightstand into a vermicomposter (worm composting system), and how to use compost tea to nourish your growing plants.