Not Eggshells, Not Coffee Grounds: An Overlooked Food Scrap Worth Adding To Compost

Composting is undoubtedly awesome for the environment and great for your garden. While many beginner composters know how to save their coffee grounds, banana peels, and eggshells for the compost bin, there's another great material you should be tossing in there, too: avocado peels. They might look too tough to break down easily — and that instinct is partially correct. But with a little extra help from your kitchen scissors, they can play an essential role in helping your compost break down beautifully.

To understand the role of avocado skins in your bin, it helps to distinguish between the two types of compost material: green matter and brown matter. Green matter refers to the wet, squishy bits of material in your bin, like leftover veggie scraps or coffee grounds. Brown matter is the tougher, drier material, like dead plants or newspaper. Brown matter in particular is what prevents your compost from turning into a slimy soup of rotten goop.

While the tasty green parts of an avocado are green matter, the skin and pit are brown matter. This means they're incredibly important to the composition of your compost! But because the peels and pits are tough, you'll have to cut them up first before tossing them in. This is generally good practice for all your composting material; smaller chunks mean faster decomposition. 

If you're branching out into vermicomposting (composting with worms), avocado shells should definitely be on your radar. Worms love them – especially red wigglers. Avocado shells actually act as a kind of aphrodisiac for worms; they like to huddle and mate inside the shells. And just when we thought millennials were the biggest avocado fans!

Beyond the bin, you can upcycle avocado shells around the house in other ways, like using them as biodegradable plant holders. They're a great size for herb or veggie seedlings, and when they're ready to be planted, you can bury the avocado shell along with it as instant compost. 

Or you can use them one last time in the kitchen. After making a big batch of guac for a summer party, hang onto those shells. Some people swear that rubbing avocado skins on corn yields a richer result — kind of like a healthier, plant-based butter. Or use the shells as mini serving dishes for your guacamole. Now you have plenty of uses for your avocado shells before tossing them in the compost!