Ask Mom Detective: How Do I Compost?

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SHELLY IN PENNSYLVANIA ASKS:

My son learned about composting in fourth grade science class and now wants to compost at home. I always try to support his interests, but I don’t know anything about composting. How complicated is it, and is there more than one way to compost? I’m concerned about wildlife coming to a compost pile in our yard.

MOM DETECTIVE ANSWERS:

You got this, Shelly! Compost is such a great system: you take food scraps and yard trimmings that would otherwise be hauled off to become waste in a landfill and instead help them decompose locally into nutrient-filled matter that you can use to amend and boost soil. Compost helps grow more plants, including edible ones that then make more scraps and … more compost. What an amazing loop!

This is such a useful outcome for food scraps. When you place them and other organic waste in plastic trash bags in a landfill, they decompose slowly—and without adequate oxygen. This produces methane, a potent greenhouse gas. Landfills across the U.S. account for more than 14% of U.S. methane pollution, releasing as much greenhouse gases as 66 million gasoline-powered vehicles driving for a year. The Environmental Protection Agency says wasted food is responsible for 58% of landfill methane emissions. So your son’s simple request to compost will help your family reduce greenhouse gases in a very real way. Here’s how.

Tell EPA: Keep Families Safe From Landfill Methane Pollution

It’s OK to be lazy

I think composting is part science, part art. There are trained master composters out there. Hats off to them. They’re meticulous humans doing it the best way. Maybe you will even become one! But it’s useful to know, especially when you’re just starting out, that it’s OK to be a lazy composter. I am. Mostly I divert organic matter from the landfill by putting it in a pile in my yard. This is a very worthy endeavor and can even be done in cold weather and snow.

Here are the basics: Some people use bins or tumblers, others build fences around open areas, still others sink buckets into the soil. What you then place in your bin or compost pile should contain a mix of:

• Carbon-rich materials (a.k.a. browns)
• Nitrogen-rich materials (a.k.a. greens)
• Water (moisture)
• Air (oxygen)

This is probably what your son learned about in school. I’m busy and my pile—which we started by simply tossing stuff in one spot in the yard without a bin or a fence 11 years ago—is mostly greens. We have a very large stainless steel bowl in the kitchen where we collect scraps. (We fight about who should empty this constantly.) I know that if the pile is too wet, I should add browns, and if it’s too dry, I should water it. And you’re supposed to turn this stuff over to mix it up from time to time.

Guess what? I don’t do any of these things. Sometimes, when I garden, the pile gets some leaves. It hasn’t rained much lately, but eventually it will. That’s the only water our pile gets. I don’t turn it over. And yet when we dig into the middle of this poorly tended pile, there’s rich compost and telltale happy worms! We use this on our plants both decorative and edible. Is it the best compost around? No. Does it reduce landfill waste and also fertilize our yard somewhat? Yes. One day, I hope to make a more legit version of compost. For now, this method does not feel like an insurmountable chore, so it works for us. If we had tried to compost perfectly, I suspect we wouldn’t be diverting as much waste from the dump.

What you can and can’t compost

Not everything should go in a backyard compost set up. Some careful composters cut allowable items into small bits before adding to their piles to speed the process along. I don’t. But even lazy composters must follow these guidelines:

Yes

• Fruits and veggie scraps (take off the plastic produce stickers)
• Cooked veggies—but only small amounts
• Paper tea bags (take out the staples, and keep in mind a lot of tea bags are plastic)
• Eggshells
• Yard stuff like grass clippings, dry leaves, twigs, plant cuttings
• Paper, brown bags, and shredded cardboard—but only if not glossy, waterproof, or colored
• Hair and nail clippings

No

• Fatty stuff: meat, fish, bones, cheese, dairy products
• Compostable bags and packaging—despite their name, these won’t decompose in a yard pile
• Yard clippings that have been treated with conventional pesticides or herbicides
• Diseased or pest-infested plants
• Pet waste, including cat litter
• Dryer lint (some people disagree, but it can contain a lot of microplastics!)
• Any glossy paper products
• Produce stickers
• Diapers or period products

There are many ways to compost

Before we started our lazy pile, we lived without a yard in New York City. There, we tried other compost options, including:

1. Community drop-off. Save scraps either in the fridge or the freezer and bring them to a compost collection site weekly. These are common in densely populated places like cities and are often found at farmers’ markets and community gardens.
2. Home compost machines. Electric composters can be great for apartment dwellers. We tried one after friends raved about theirs. We struggled to make it work—our abundant scraps got wet and smelly. We did enjoy our escapades trying to give away the compost, though, including “feeding” the tree beds in front of our building in the dark of night.
3. Household pickup. Some municipalities offer curbside composting or pickup, plus there are private companies that haul scraps for a fee. Bonus: Some pickup operations can take fats and meats, which most backyard piles are not big enough or hot enough to handle.
4. Worm bins. This is exactly what it sounds like: you procure specific worms (red wigglers are said to be the best), place them in a bin, and make sure the mix of bedding and scraps is the proper ratio. Then the worms eat the scraps and leave you with vermicompost, which has even higher nutrients than regular compost. A worm bin can provide kids with many lessons in microbiology, and yet my family banned me from placing one under my bed knowing I was too lazy to prevent fruit flies. Meanies!

Wildlife

While most people concerned about compost and wildlife are thinking about rodents, those in my neck of the deep woods are also worried about bears. Either way, the main solution is to not be lazy. My pile regularly feeds birds, two groundhogs we have affectionately named Jeremiah and Jupison, foxes, and more. I love our wild animal menagerie, but if we had rats or bears, I would feel differently. A well set up bin with the correct mix of browns and greens that has a lid and no gaps or holes should not attract wildlife. Another anti-wildlife tip is to bury food scraps in the pile, rather than just tossing them on top. Even I think this is doable.

I hope you and your son have a blast learning how to compost—and fighting methane pollution and the climate crisis—together.

Learn more about Moms’ work on methane.

Tell EPA: Keep Families Safe From Landfill Methane Pollution