Understanding the Combination of Browns and Greens for Compost

Published
Understanding the Combination of Browns and Greens for Compost

Composting is a great way to add nutrients and organic material to your garden while reducing the amount of garbage we send to the landfills. Many people who are new to composting wonder what is meant by creating a balanced browns and greens mix for compost. What is brown material for compost? What is green material for compost? And why is getting the right mix of these important?

What is Brown Material for Compost?

Brown materials for composting consists of dry or woody plant material. Often, these materials are brown, which is why we call them brown material. Brown materials include:

  • Dry leaves
  • Wood chips
  • Straw
  • Sawdust
  • Corn stalks
  • Newspaper

Brown materials help to add bulk and help allow air to better get into the compost. Brown materials are also the source of carbon in your compost pile.

What is Green Material for Compost?

Green materials for composting consists mostly of wet or recently growing materials. Green materials are oftentimes green in color, but not always. Some examples of green materials include:

  • Food scraps
  • Grass clippings
  • Coffee grounds
  • Manure
  • Recently pulled weeds

Green materials will supply most of the nutrients that will make your compost good for your garden. Green materials are high in nitrogen.

Why You Need a Good Browns and Greens Mix for Compost

Having a proper mix of green and brown materials will ensure that your compost pile works properly. Without a good mix of brown and green materials, your compost pile may not heat up, may take longer to break down into useable compost, and may even start to smell bad. A good mix of browns and greens in your compost pile is about 4:1 browns (carbon) to greens (nitrogen). That being said, you may need to adjust your pile somewhat depending on what you put in it. Some green materials are higher in nitrogen than others while some brown materials are higher carbon than others. If you find that your compost pile is not heating up, than you may need to add more green material to the compost. If you find that your compost pile is starting to smell, you may need to add more browns.

Dr Heidi Parkes

By Dr Heidi Parkes

Senior Information Extension Officer QLD Dept of Agriculture & Fisheries.