Can You Compost Onions and Garlic?
Yes. Onion and garlic scraps compost well in a backyard pile. The two catches: whole bulbs may sprout, and worms dislike them. Chop them up and keep them out of the worm bin.
At a glance
| Home compost pile | Yes |
|---|---|
| Green or brown | Green (nitrogen-rich) |
| Moisture | Wet |
| Prep | Chop into small pieces |
| Worm bin | No |
| Bokashi | Yes |
How to compost onions and garlic
Chop ends, skins and spoiled bulbs before adding them so nothing sprouts. Dry, papery skins act like a brown and can go in freely. Mix fleshy scraps into the center of the pile with the rest of your kitchen waste.
Save onion skins for stock or natural fabric dye before they go on the pile.
What goes wrong
A whole onion or garlic clove tossed on top can sprout and root into the pile. Cut them up or bury them deep. Rotting onions smell strongly, so cover them with browns straight away.
Worm bins and bokashi
Worm bin: Keep onions and garlic out of worm bins; worms avoid them and the smell builds up.
Bokashi: Onions and garlic ferment fine in bokashi, which makes it a good home for them if your only other option is a worm bin.
This counts as a green. Adding a lot of it? Check the balance with the compost mix calculator.
From hopcompost.com/can-you-compost/onions-and-garlic/ · General guidance, not professional advice.
Frequently asked questions
Why do people say not to compost onions?
The advice comes mostly from worm composting, where onions and garlic are unwelcome. In a regular backyard pile they break down normally.
Will onions sprout in my compost?
Whole bulbs and cloves can. Chopping them, or burying them in the warm center of the pile, stops that.
Do onion skins count as greens or browns?
Dry, papery skins behave more like a brown. Fleshy scraps and spoiled bulbs are greens.