Can You Compost Corn Cobs?

Updated

On this page
  1. At a glance
  2. How to compost corn cobs
  3. What goes wrong
  4. Worm bins and bokashi
  5. FAQ
Yes

Yes. Corn cobs and husks compost well, but whole cobs are dense and can take a year or more in a cold pile. Split or chop them, and they help keep the pile airy while they work.

At a glance

Home compost pileYes
Green or brownBrown (carbon-rich)
MoistureDry
PrepChop into small pieces
Worm binWith care
BokashiWith care

How to compost corn cobs

Split cobs lengthwise or cut them into 2–3 in (5–8 cm) rounds before adding them. Husks and silk go in as they are and act as a brown once dry. Chop garden stalks or run them over with a mower first.

A few whole cobs at the base of a new pile help air move under the heap while they slowly break down.

What goes wrong

Whole cobs survive a long time and show up in finished compost. Sift them out and toss them into a new pile, where they keep breaking down. Buttered or salted cobs are fine in small numbers, but bury them so animals don't dig.

Worm bins and bokashi

Worm bin: Worms nibble cobs slowly; husks and chopped cobs are fine in small amounts, but whole cobs linger.

Bokashi: Cobs come out of bokashi mostly intact, so they're better off in the regular pile.

This counts as a brown. Adding a lot of it? Check the balance with the compost mix calculator.

Frequently asked questions

Are corn cobs green or brown?

Brown. They're dry and carbon-rich. Fresh husks are a little greener but dry out quickly.

How long do corn cobs take to compost?

Whole cobs can take a year or more in a cold pile. Chopped cobs in a hot, turned pile break down in a few months.

Can you compost corn husks and stalks?

Yes. Husks break down quickly. Stalks are tough, so chop or shred them first, as with straw.