So That's Why We Shouldn't Put Yard Waste In The Trash

Your local trash pickup might have a yard waste option, but why are they separate? I'm shocked how long it took me to learn the reason.

• Compost
• Fermentation
• Gardening

When you create a compost pile, you’re layering various types of organic material, typically referred to as “greens” (nitrogen-rich material like food scraps) and browns (carbon-rich material like dried leaves). Subsequently, the wild bacteria and other microbes from your soil (and from the greens and browns) start to break down the organic matter into soil. Depending on the conditions, one of two processes can occur: composting (what we want) and fermentation (what we don’t want).

Even though this is a site that is very pro-fermentation, the type of fermentation that can happen in your compost pile can actually cause it to smell, as the organic matter gets converted into byproducts that not only won’t result in the compost we’re after (at least not without an additional composting phase) but can also release methane into the air (which traps more heat in the atmosphere than carbon dioxide). This is the result of anaerobic (without the presence of oxygen) activity, commonly due to compaction (lack of turning) or excessive moisture filling the spaces and forcing the oxygen out. This can also occur if there are too many “greens”, meaning the aerobic bacteria don’t have enough carbon to work with and allowing the anaerobic bacteria to take over.

It stands to reason, then, that in a landfill, as load upon load of trash is heaped on top, the lower layers get compacted, rain waters get trapped, and oxygen gets forced out. Landfills don’t get aerated, and there’s certainly no control over the ratio of nitrogen to carbon, so anaerobic fermentation takes over and releases methane into the atmosphere.

With your backyard compost pile, this is easy to control. Just aerate it. Take a pitchfork, dig into the center of the compost pile (where active decomposition is occurring), and expose that to oxygen. If it smells bad, all the more reason to keep turning the compost. Thankfully, any bad smells should be short-lived as long as it’s due to a lack of oxygen (if it’s due to lack of carbon, add some “browns” and mix them in). Continue aerating and mixing the pile together every couple of days and before you know it you’ll have high- quality compost ready for your garden (I’ve seen people say that it can take as little as 14 days, but I have yet to see it happen that quickly).

And this is why it’s bad to put yard waste in your trash bin (and might even be an argument that you should be composting as much as possible). Everything compostable that ends up in the trash goes to the landfill to be compacted and left to decompose anaerobically, releasing harmful methane into the atmosphere where it can’t be utilized and instead contributes to the warming of our atmosphere.