Composting 100% Cotton: A Complete Guide


According to cottontoday.com, composting 100% cotton fabrics, clothing, and cotton waste can contribute significantly to the organic matter content of compost, enriching its nutrient profile. Composting takes time, but by following a few basic steps, you will have rich organic matter in 6-12 months.

Optimal composting requires sufficient moisture, warmth, oxygen, and microbial activity. Below is a Step-by-Step Guide to composting 100% cotton jeans, fabrics, clothing, and cotton waste. A downloadable PDF guide is located halfway down the page.

Step-by-Step Guide to Composting 100% Cotton (and jeans)

1. Confirm the Material

  • Make sure the jeans are 100% cotton…look at the label
  • Check for synthetic blends (like polyester, elastane, or spandex). If any synthetic (plastic) fibers are listed, the clothing, jeans, or textile cannot be composted.
  • Remove all:
    • Zippers
    • Buttons
    • Rivets
    • Synthetic threads (if possible)
    • Tags or labels (often polyester or nylon)

2. Cut or Shred the Fabric

  • Cut the jeans into small pieces, ideally 1–2 inch squares or strips by using a rotary cutter.
    • This speeds up decomposition.

3. Balance the Compost Pile

  • Denim counts as a “brown” (carbon-rich) material.
  • Pair with plenty of “greens” (nitrogen-rich) like:
    • Food scraps (fruit/veg peels)
    • Grass clippings
    • Coffee grounds

4. Layer and Mix

  • Alternate layers of shredded denim with greens.
  • Maintain a good mix (approx. 2 parts brown to 1 part green).
  • Don’t overload your compost with denim—keep it to less than 25% of the total volume.

5. Maintain the Pile

  • Aerate: Turn the compost regularly (every 1–2 weeks).
  • Moisture: Keep it damp like a wrung-out sponge. Add water if it’s too dry.
  • Temperature: A hot compost pile (130–160°F or 54–71°C) will break down denim faster.

6. Be Patient

  • Even under good conditions, denim may take 6–12 months (or more) to fully decompose.
  • If large pieces remain after this time, remove and re-cut them before reintroducing.

Downloadable PDF guide

Optional Tips

  • Use a fabric-only compost bin if you do this often, to avoid confusing your regular food compost.
  • If you don’t compost at home, look for textile recycling or industrial composting facilities that accept natural fabrics.

Factors That Affect Composting Time:

  • Fabric Thickness & Weave: Denim is thick and tightly woven, which slows down decomposition.
  • Dyes & Finishes: Synthetic dyes, chemical treatments, or water-resistant coatings can significantly delay biodegradation.
  • Environment:
    • Compost heap: 1–5 months
    • Landfill: 10+ years
    • Buried in soil: 6 months to several years, depending on conditions