Compost Ingredients

Our guide to the good, the bad, and the so-so compost ingredients.

By Willi Evans Galloway


what to add to your compost pileBuilding a compost pile creates more anxiety and obsession among gardeners than any other gardening activity. So before you start a pile, remember one thing: Relax.

"There's no right or wrong way of composting, and people get panicked that they have the wrong recipe," says Dr. Maynard. "Composting is a natural phenomenon—it's decomposing; you're just helping it along a bit." That said, there are good, bad, and so-so compost ingredients. So before you add an ingredient to your pile, make sure it's up to the compost quality-control test. Ask yourself four basic questions about each ingredient:

1. Is it biodegradable?

2. Will it help make high-quality, nutrient-rich compost?

3. Did it come from a chemical-free lawn?

4. Is it free of disease, toxins, and other contaminants?

If you answer "no" or "I don't know" to any of these questions, forgo adding the ingredient to your pile. It's that easy. Mix and match the green and brown ingredients listed below until you find a compost recipe that works for you. Just keep in mind the carbon-to-nitrogen (C/N) ratio as you build your pile.

The Good Stuff


  • Aquarium water, algae, and plants (from freshwater fish tanks only) add moisture and a kick of nitrogen.
  • Chicken manure has high amounts of nitrogen, phosphorus, and potassium.
  • Dead houseplants add a dose of nitrogen, but don't include thorny or diseased plants.
  • Fresh grass clippings should be mixed with plenty of drier, brown material, or you'll risk creating a smelly pile.
  • Green garden debris, such as spent pansies, bolted lettuce, and deadheaded flowers, can all be recycled in the compost bin.
  • Horse manure contains more nitrogen than cow manure.
  • Manure from pet rabbits and rodents (e.g., gerbils and hamsters) can be composted with the accompanying wood or paper bedding.
  • Vegetative kitchen scraps (carrot peelings and the like) should be buried in the pile so they don't attract animals. Eggshells are okay, too.
  • Weeds can be composted! No joke. Just remember never to add weeds that have set seed or weeds that root easily from stems or rhizomes, such as field bindweed and Canada thistle.




  • Brown garden debris, such as corn and sunflower stalks, dried legume plants, and dried potato and tomato vines, adds bulk to the pile.
  • Hedge prunings and twigs help keep a pile fluffy but should be chipped first so they decompose faster.
  • Leaves are an abundant carbon source and full of nutrients. Stockpile them in fall so that you have them on hand in summer.
  • Pine needles decompose slowly. Add only small amounts to your pile. Use excess needles as a mulch.
  • Straw bulks up a pile, but it should not be confused with hay, which often contains weed and grass seeds and shouldn't be added to compost (unless you want to deal with the potential consequences).

Turn kitchen scraps into super-fertile soil!  Learn more.

New for your e-reader or tablet: Compostology 1-2-3.