Can You Compost Citrus?

Dear Torn About,

I once spent seven hours standing at a table on a garden tour, talking about composting. Yes, it’s a glamorous life I lead; don’t be jealous.

The question I heard again and again throughout the day was, “Can you put citrus peels in the compost pile?” Frequently, it wasn’t even posed as a question, but rather as a statement in the negative. And, oddly, I heard from any number of people that a son or daughter or husband or wife wouldn’t let them put citrus in their compost piles. Not putting citrus in the compost pile must be one of the most entrenched myths about composting; everyone knows it’s a bad idea. As it turns out, all those everyones are wrong. Citrus peels and whole citrus are a great addition to the compost pile, and they break down as readily and as thoroughly as any other ingredient (and better than some). Let’s explode a few myths.

Myth: Citrus peels contain a chemical that keeps them from breaking down in the compost pile, or will cause your compost pile to stop working.

Truth: Citrus peels are a great addition to the pile, break down easily and quickly, and contain no chemicals adverse to the composting process. Citrus does contain some strong compounds, but none of them prevent or harm the composting process. I’ve been composting citrus peels for years and have never had a problem.

Myth: Whole citrus cannot be added to the compost pile because they won’t break down.

Truth: There is a grain of truth to this one, but only a grain. Certain citrus, most notably the Sour or Seville Orange, will not break down if the peel is perfectly intact. My guess is that the oils and acids of the rind prevent the entry of composting micro-organisms.

If, however, the peel has even the slightest cut or scrape or opening, the fruit will compost quickly and completely. When adding whole citrus to your compost pile, simply take a half a second and make certain the rind is cut. Or, just take a jab at them with your spading fork whenever you turn the pile; it’s good practice for hand-eye coordination.

Myth: Citrus will make your compost acidic, and that’s a bad thing.

Truth: To the contrary, it’s often a good thing. For instance, soils in the desert are highly alkaline, so slightly acidic compost in such regions will be beneficial.

While some native and adapted plants do fine in naturally alkaline soils, the vegetables and flowers grown in compost-amended soils prefer a soil pH of around seven to slightly below, so if our compost ends up acidic, so much the better.

Myth: OK, fine, some citrus is acceptable, but you have to be sure not to add too much.

Truth: You can’t add too much citrus to your compost pile, but you can add too much in proportion to other ingredients. But that’s
true of anything.

I did have one woman tell me that she filled her compost bin to the top with citrus and citrus peels and it didn’t make compost. When I asked what else was in the bin, she said, “Nothing, just the citrus.” And therein lay the problem.

Citrus is considered a “green” or nitrogen-bearing material. The basic recipe for compost has four necessary ingredients: carbon, nitrogen, water, and air. Absent any of the four, the process won’t work. A bin full of nothing but citrus won’t produce compost any better than a bin full of nothing but grass or lettuce leaves; that it’s citrus is irrelevant. So go ahead and add as much citrus as you want, but be certain to add an equal amount of carbon-bearing material at the same time.

Myth: My husband (or wife or daughter or son) won’t let me put citrus in my compost pile.

Truth: In every life there comes a moment when we are called to stand strong in defense of truth, integrity, values, and honesty, no matter who may be challenging our principles or tempting us to infidelity. This is not that moment. But just for practice tell him to buzz off and get his own darn pile.

Hope that helps,

Tyler