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How to Compost Weeds

By Barbara Fahs ; Updated September 21, 2017

You can compost almost any type of plant. Weeds provide a great filler for compost piles because many of them, such as grassy weeds, are high in nitrogen and other beneficial nutrients. However, weeds that have gone to seed are not good additions to a compost pile because those seeds often sprout and then introduce many more weeds to your garden when you use the finished compost. The heat that a compost pile generates will kill or inactivate some weed seeds, but to be on the safe side, choose weeds for your compost pile that have not yet formed seeds. According to the Howard formula for composting weeds, “Some of the very worst weed villains make the very best of compost.”

Composting With Weeds

Mow or weed whack grassy weeds such as crabgrass, and then rake and collect the material. Do this before any seeds have formed.

Layer your grassy weeds alternately with layers of dried, brown plant material such as fallen leaves or other plant parts in order to keep your compost oxygenated and prevent an anaerobic situation, which can cause your compost to smell unpleasant.

Pull weeds such as plantain, mallow or spurge by hand and then snip off the roots before you place them in your compost pile. You can include the roots, but if you leave them on there’s a chance the entire plant will continue growing in the compost pile.

Include dry plant material between layers of all fresh, green weeds that you add to your compost.

Turn your compost pile every 3 to 4 days with a pitchfork to accelerate the composting process.


Things You Will Need

  • Lawnmower or weed trimmer
  • Rake
  • Area for a compost pile
  • Green, fresh weedy plant material
  • Dried, brown plant material
  • Pitchfork


  • It's a good idea to chop up all plant parts you put into your compost pile because smaller pieces will compost faster than larger pieces.
  • Avoid adding weed plants with thorns to your compost. Also avoid hard, shiny plant parts, such as fir needles.


  • Avoid using any weed plants that appear to have disease.
  • Some plants, such as mint, easily root---even if you chop them up, there's a chance they will survive the heat a compost pile generates and then they can invade your garden when you use the compost.

About the Author


Barbara Fahs lives on Hawaii island, where she has created Hi'iaka's Healing Herb Garden. Fahs wrote "Super Simple Guide to Creating Hawaiian Gardens" and has been a professional writer since 1984. She contributes to "Big Island Weekly," "Ke Ola" magazine and various websites. She earned her Bachelor of Arts at University of California, Santa Barbara and her Master of Arts from San Jose State University.