Can You Compost Fish?

Updated

On this page
  1. At a glance
  2. What to do with fish instead
  3. What goes wrong
  4. Worm bins and bokashi
  5. FAQ
No

No, not in a backyard pile. Fish scraps smell strongly as they rot and attract cats, raccoons and rats. Bokashi or municipal food-scrap collection handles them better.

At a glance

Home compost pileNo
Green or brownNeither (not a green or brown input)
MoistureWet
PrepNone needed
Worm binNo
BokashiYes

What to do with fish instead

Municipal organics programs usually accept fish. Bottled fish emulsion gives your garden fish-based nutrients without the smell.

Keep fish, skins, heads, bones and shrimp shells out of home piles. Freeze scraps until your food-scrap collection day, or ferment them in bokashi and bury the result deep. Cleaned oyster and clam shells are a separate case: they're harmless but take years to break down.

What goes wrong

Fish in an open pile tends to get dug up within days and smells for weeks. Bury it deep under browns or remove it. If the smell lingers, add plenty of dry browns and turn the pile.

Worm bins and bokashi

Worm bin: Keep fish out of worm bins; it rots faster than worms can eat it and smells badly.

Bokashi: Bokashi handles fish scraps; expect a stronger smell when you open the bucket, and bury the contents deep.

Balancing the rest of your pile? Check the balance with the compost mix calculator.

Frequently asked questions

Can you compost shrimp shells?

Treat them like fish: keep them out of open backyard piles. Use bokashi or municipal collection.

Can you compost fish bones?

Not in a backyard pile. Bones break down slowly and attract animals. Bokashi or municipal collection is the better route.

Can you compost oyster and clam shells?

Clean shells can go in, but they take years to break down. Crush them first, or put them out with municipal organics if accepted.