What Can You Compost? The Complete Guide

Honestly, “can I compost this?” is probably the question I get asked more than anything else. And the answer really does depend on your setup — backyard pile, worm bin, or Bokashi bucket all have their own rules. So I put together the most complete guide I could, broken down by category, because I got tired of Googling the same stuff over and over.

Kitchen Scraps: Yes to All of These

Good news — your everyday kitchen scraps are pretty much all fair game. Vegetable peels and scraps, fruit skins and cores, coffee grounds and paper filters (I go through so many of these), loose leaf tea and plastic-free tea bags, eggshells, bread and crackers in small amounts, cooked rice and pasta in small amounts, nutshells (walnuts are the one exception), herbs and spices, and expired flour or cornmeal all compost just fine in any composting system. Pretty much your whole cutting board can go in the bin.

Kitchen Items: It Depends

This is where it gets a little nuanced. Citrus peels are totally fine in an outdoor pile, but dump a ton of orange rinds into a worm bin and your worms will basically go on strike — they hate the acidity. Same story with onion skins. Dairy and meat are the big ones people always ask about. They’re actually compostable in a Bokashi system, which is designed for that kind of stuff, but in a regular backyard pile? Skip them. They’ll have every raccoon in the neighborhood showing up for dinner.

Paper and Cardboard: Yes

This one surprised me when I first started composting — so much of your paper waste can go straight into the pile. Newspaper, paper bags, plain cardboard, paper towels and napkins, paper coffee cups without a plastic lining, toilet paper and paper towel rolls, egg cartons — all of it breaks down really well. Just tear or shred your cardboard first. I learned that the hard way after tossing in a whole cereal box and finding it still mostly intact three months later. Paper is actually one of the best “brown” materials you can use for balancing out all those wet kitchen scraps.

Garden Waste: Yes

Your yard is basically a compost goldmine. Grass clippings, fallen leaves, plant trimmings, spent flowers, weeds that haven’t gone to seed, straw, hay, wood chips — all great. Two things to watch out for, though. Diseased plants should go in the trash, not the pile, because most home setups don’t get hot enough to kill off the pathogens. And thick branches need to be chopped or chipped down small first, otherwise you’ll be waiting a very, very long time.

What Never to Compost at Home

Some things just don’t belong in a home compost pile, full stop. Pet waste can carry parasites you really don’t want anywhere near your garden. Treated wood, glossy or coated paper, synthetic fabrics, and personal hygiene products either don’t break down or leave behind stuff you don’t want in your soil. Large amounts of cooking oil will mess with your pile’s moisture balance and can attract pests. And anything that’s been treated with pesticides — just bag it and toss it. Not worth the risk.

Final Thoughts

My husband actually uses a little mental shortcut I told him about: was this once alive, and is it free of synthetic chemicals and coatings? If the answer to both is yes, it almost certainly composts. The longer you do this, the more it just becomes second nature — you stop even having to think about it. Bookmark this page for when you’re standing at the bin with something weird in your hand wondering if it belongs in there. We’ve all been there.