As proponents of composting (or at least using kitchen scraps as plant food) we’re always on the lookout for tips and tricks that could improve the process, or (better yet) make it easier. This includes knowing what should—and, just as importantly, what shouldn’t—end up in the compost pile or bin.
Fortunately, Maki Yazawa at Well+Good wrote an article outlining the best and worst foods to compost. Here’s what to know.
The best foods to compost
According to Yazawa’s research—including expert interviews—there are some of the best foods to compost:
Coffee and tea
This one’s well-known, but a classic for a reason: Coffee grounds contain nitrogen, which helps with the composting process. Plus, if you use unbleached coffee filters, those can be composted too. Same goes for tea: As long as the teabag is biodegradable and made from compostable materials, go ahead and throw the whole thing in.
Fruits
Fruits, in general, are popular additions to compost piles, thanks to all the nutrients they provide. However, some parts take longer to break down, like pits from avocados or stone fruits (like peaches and nectarines), or tough rinds (like some types of melon). It’s also a good idea to keep an eye on the amount of acidic fruits—like tomatoes and citrus fruits—you add to the compost pile, as they can throw off its pH.
Vegetables
Meanwhile, vegetables are much easier to compost, primarily because they can go in whole, as scraps, rotten, cooked, or raw.
Leftovers
Leftovers, including “undressed vegetables, grains, and pasta, as well as boneless pieces of lean meat and protein” can all be composted, Yazawa writes.
The worst foods to compost
While technically, most foods can be added to a compost pile, the Environmental Protection Agency (EPA) advises against including the following items—primarily because they can cause foul odors, or attract pests:
Dairy products, like butter, milk, sour cream, yogurt
Eggs (although eggshells are fine)
Fats, grease, lard, or oils
Meat or fish bones
Lastly, the EPA says to avoid composting black walnut tree leaves or twigs, because they release substances that might be harmful to plants.