Use Concrete Blocks For A Durable Alternative To A Compost Bin

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Making compost in your backyard will keep organic waste out of landfills, plus yield a rich (and free!) soil amendment that your plants will love. Though there are some things you cannot put in your compost, usually the trickiest part of backyard composting is getting a make it. That's why many handy gardeners DIY their own compost bins using everything from wood pallets and cardboard to plastic buckets and bags.

But if you want something that's sturdier than cardboard, easier to put together than wood and wire, and more durable than most other DIY compost bins, you'll just need some concrete blocks, also known as cinder blocks. These hollow blocks create airflow that aerobic bacteria need, which speeds up the decomposition process and supercharges your compost pile. Here's how you can build a durable compost bin using simple concrete blocks, no mortar required.

In less than a day, you can DIY a concrete block compost bin and have a tidy spot for your compost for many years to come. First, to complete a single enclosure, you'll need about 30 to 35 concrete blocks. Start by building the back wall by laying a row of four to five blocks, keeping the hollow sides parallel to the ground to improve airflow. Alternatively, you can set the hollow sides perpendicular to the ground, as seen in this video from Jim Bob's Garden, but if you do, make sure to keep some space between the blocks to preserve airflow. Then, build out the two side walls using another four to five blocks, depending on how big you want the enclosure to be. Leave the fourth wall open so you can later add, turn, and check your compost's temperature.

Once you have all your rows in place, it's time to play Tetris! Just stack more blocks to build up the walls until you're done. You should have about four rows on the back wall, while the side walls can taper off toward the front. Try to stagger your blocks so they're not lined up exactly for added stability. Remember to either keep the hollow sides of the blocks facing inward or leave some space between the blocks so that air can get in and speed up the composting process. You can always add extra sections later to accommodate more compost piles, as long as you've got the blocks for it.

Putting together your own DIY concrete block compost bin is easy — finding enough free blocks to get the project done on the cheap is another story. Start by checking Facebook and Craigslist in your area. You may find someone giving away concrete blocks in exchange for simply picking them up. You can also check around local construction sites or call junk haulers to see if they have any up for grabs. 

If there's a Habitat ReStore near you, give them a call, as they sometimes have used blocks for sale at below-average prices. If you haven't found any concrete blocks for free or on the cheap after pounding the pavement and holding up the phone line, you can always break down and buy some brand-new, like these 8-by-8-by-16-inch concrete blocks from Home Depot for less than $3 each. But if, by some miracle, you end up with even more than you need for your DIY compost bin, rest assured there are plenty of other ways you can transform concrete blocks into home and garden treasures.