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Can You Compost Onions? Info-Packed Primer on Onion Composting

Onions in a compost that turned to rich soil

Can you or should you compost onions?

Yes, you can but it’s best to chop them up to prevent them from sprouting. You’re composting, not planting a garden, right?

We do without any problems but we follow the few simple steps and tips below.

Does that mean all types of onions?

Yes, it does. You can compost all types of onions.

Can you include onion skins/peels?

Yes, you can put onion skins / peel in your compost bin.

More onion composting tips to keep in mind:

  • The finer you chop up the onions, the faster they break down.
  • Don’t forget about the magical composting formula: Two parts carbon (leaves, grass clippings and straw and similar) to one part nitrogen (fruit and veggie scraps). 
  • Keep you compost moist but not soggy.  Too much moisture will get you one big pile of rotting onions instead of properly composting (breaking down) onions.  Rotting onions reek.  They really do.
  • Onions take longer than other fruits and veggies to compost so be patient.
  • Mix up the compost regularly to speed up the process.

What does including onions in your compost do for the soil you create?

A few benefits for your soil (so it’s worth composting onions).

  • They help improve soil drainage and aeration.
  • They help suppress plant disease.
  • As a mulch made in part with onions, it can help deter pests from attacking and munching your plants.

Once you have your new, rich soil from your compost, you can grow more onions.

I told you this would be short n’ sweet.