Brown Materials (Carbon)
Material
Brown materials are compost ingredients that mainly contribute carbon and structure. They balance wetter nitrogen-rich materials and help keep air moving through the pile. Common examples include dry leaves, straw, and untreated paper products.
How it works
Carbon-rich materials provide an energy source that compost microbes use more slowly than fresh greens. Browns are often drier and coarser, so they help absorb excess moisture and prevent compaction. When mixed well with greens, they support steady decomposition and reduce odor problems. Very woody browns break down more slowly and may remain visible longer in the finished compost.
Details
Store a supply of dry browns so they are available whenever you add wet kitchen scraps or fresh clippings. Mix browns throughout the pile instead of placing them all in one thick layer. Shred leaves, paper, or other bulky materials if you want faster breakdown and a more even texture. Add extra browns when the pile looks soggy, smells unpleasant, or loses its shape.
Tips
Dry browns are often the easiest correction for common compost problems. Keep them protected from rain so they stay absorbent. A compost system usually runs better when browns are added more often than gardeners first expect.
General guidance for US home gardens. For local guidance and any rules on composting, contact your Cooperative Extension office. Page updated Aug 4, 2026.