Composting Onions: Yes, But Chop Them and Bury Deep

Onions can be composted, but whole onions may sprout. Chop into halves/quarters first. Onion skins and scraps don’t sprout but can smell strongly and attract pests/dogs. Bury at least 10 inches deep. Larger pieces decompose slower. Crushed oyster shells, newsprint, or cardboard help control odor.

Important Exception: Vermicomposting

Do not add onions to worm bins. Worms dislike odorous, acidic scraps—onions, garlic, broccoli, potatoes. High acidity upsets their digestion.

In regular compost, onions don’t harm microbes—just your nose occasionally.