Why you should pee on your compost

And other gross things you can add to your pile, because it's fun and we all embrace being disgusting animals (right?).

I don’t think of myself as a very fussy composter. In my opinion, almost anything is worth at least trying to compost—and a lot of the rumors you hear about what you “absolutely shouldn’t” put in your pile (citrus, egg shells), are frankly untrue, albeit likely came from well-intentioned gardeners who saw that some things are harder to break down and/or more likely to attract animals. I appreciate their concern, but also want to encourage all brave and enterprising new composters to experiment freely and learn the lessons and preferences of their own pile. If you’re nervous, you can segment your compost in order to experiment without risking “contamination” of the parent pile. If you’re brave or reckless (like me, I’m reckless), you can just throw everything together and see what happens. The fun of compost is that it’s, well, kind of entirely up to you. What you put in your pile is your choice, based on how much time and energy you have, and contingent on what you plan to do with the finished product. Most stuff ends up working out, i.e. decaying.

One thing to consider, when weighing what to add, though, is whether or not you have hot compost. If your pile is thermophilic (consistently above ~105°F, but honestly I feel best at about ~140°F), that means bad stuff like pathogens are more likely to just get cooked out. You’re pretty safe adding almost anything** to a hot compost.

So, here is my unofficial list of things you should add to your pile, even if you’re definitely-maybe-sort-of not supposed to:

• Citrus Peels

I wish I knew why people say you can’t compost citrus. It baffles me. Citrus is a great source of nitrogen, which any heap needs. It also offer phosphorus, and potassium, which your future plants—if you use your compost to garden—will love. There are some things to be aware of when adding citrus, like how dumping ten pounds of lemon peels in at once will increase the overall acidity of your pile, which your plants might then hate. You can avoid this by adding them in balanced portions with other types of food scraps, or covering them with a good, bulky carbon material like dead leaves. Yum.

• Egg Shells

I’ve seen people scaremongering about salmonella, and posting advice that you should avoid putting egg shells in your pile. Pish. Egg shells are a fantastic add to any pile. They are a great source of calcium, and can help adjust your overall pH if your compost is on the acidic side. They do take awhile to break down if you add them without crushing or grinding them, though.

• Mold

This one, admittedly, makes me laugh. Not only is it okay to compost mold, you absolutely should compost mold. Mold on food signals that the material has already started to break down, which is good!, and you’ll diversify and enhance the fungal populations of your pile.

• Pee

I love telling people to pee on their piles because, at heart, I am seven. But in all seriousness, urine is high in nitrogen and can function as a fantastic compost activator. If your pile isn’t decaying at a good clip, and you want to help speed things up, go ahead and piss on it. Pee can be especially helpful if your pile is heavy on carbon (dead leaves, wood chips). I manage the compost pile at a friend’s house, and after filling the bin with yard waste from where we cleared out space for a garden, I told him to take a whiz on top. Two days later, the bulky leaves and weedy grasses had almost entirely disappeared. Chef’s kiss.

• Hair

You can compost hair! It takes a minute to break down, but it slowly releases nitrogen into the pile as it decays, providing your heap with a steady source of a critical chemical. This applies to all kinds of hair, too, for what it’s worth. Human hair, dog fur, cat hairballs, etc.

• Nails

Also a great source of slow-release nitrogen. Bonus: if you clip your nails directly over your pile, it will weird out your terrible neighbor who’s always spying on you, and they’ll stop. (I did this and it worked, trust me.)

• Weeds

There is a saying that you shouldn’t compost weeds, but I think of it as more of an advisory than a hard rule. You can totally compost weeds, but it’s best done if your pile is consistently above 140°F. That’s the tempearature at which most weed seeds are instantly killed. Not all of them, though, so it’s worth doing your research, first! Also, if a few weed seeds end up in your finished compost, you’re not likely to … you know… die or something. You’ll just weed them out of your garden, as you tend.

• Onions

Yes, you can compost onions! If you’re adding whole onions, they can rot and smell extremely bad as they do, though, so add them deep in your pile, and make sure they’re covered with a good mixture of browns (sawdust, soil, leaves).

There you go! I hope this frees you to have a little fun with your pile, and also do some gross things to it.

Love, Cass

PS. I want to thank Noah Kalina for recommending my newlsetter, and sending me hundreds of new compost-curious subscribers. I’ve loved hearing from you all, and I will be answering your questions soon! In the meantime, let me know if you pee on your piles.

**anything within reason, people! don’t sue me.