Decomposition occurs naturally over time, affecting all organic matter. Managing the process for soil improvement in a compost pile provides rich organic material for the garden. It is a simple process, often likened to a recipe for baking a cake—combining the right ingredients in the right proportions under proper conditions.

Following a composting “recipe,” however, is only one method; yet, it is the route to generating a final product in the least amount of time. When there is no concern about time, a simple pile may be added to as materials are generated, then ignored. Eventually the collected organics will decompose and become compost.

Why Compost?

• Recycle organic wastes generated in your home, landscape, and community.
• Turn kitchen and garden residues, animal wastes, and woody materials into a rich and useful soil amendment.
• Create a material that will improve structure, aeration, and drainage in all soil types.
• Provide nutrients in compost that will be available to plants over a long period of time.

Build a Hot Pile

• Make compost in only a few weeks using ingredients classified as carbohydrates and nitrogen, simply called greens and browns.
  • Reduce ingredients to small pieces—shredded or chopped.
  • Green ingredients are food wastes, plant residues, and manures.
  • Wood chips, dry leaves, paper products, and straw are examples of browns.
  • More greens than browns are needed to supply energy for the organisms that break down the pile. The ideal ratio is 30:1, generally achieved by using an equal volume of each.
  • Prevent lawn clippings and paper materials from matting by mixing them with dried ingredients.
• Moisten the pile periodically to keep it as damp as a squeezed-out sponge.
• Attempt to build the pile about 3 feet high and wide to generate and maintain heat created by microorganism activity.
• Alternate greens and browns as you build the pile.
• Turn the pile every few days to aerate and add moisture but avoid soggy conditions. Move materials in the outer edges to the center of the pile.
• In cool or rainy weather, cover the pile to maintain heat.
• High heat—best at 160 degrees F.—is needed for rapid decomposition and killing weed seeds. (Burr clover and cheeseweed seeds and oxalis bulbs are not killed.)
• Continue to add easily decomposed nitrogenous materials such as food scraps when turning the pile.

Notes

• Include other useful ingredients when available, such as urine—a sterile waste product—feathers, cotton or wool fabric, and hair.
• Make compost with materials stacked in an open pile or layered in a bin.
• Select a convenient, easy to access location for composting, optimally within the easy reach of a hose, out of wind and direct sun.
• Do not include any ashes—they do not decompose—or manure from dogs and cats.
• Avoid problems by keeping greens and browns in balance and by watering only as needed. Very dry piles slow down the process; excess moisture creates an odor.

Additional Information

• Composting Basics  (illustrates rapid method)
• Composting Hints* (brochure)
• Composting with Worms* (brochure)
• Our Composting workshops are also available on YouTube in English and Spanish.

When schools are open, we offer a program to Pre K-12th grade classes in Sonoma County.

• We provide a worm bin to a classroom or a school garden.
• We do an introductory lesson on worm composting and worm anatomy.
• We provide additional curriculum for the teacher.
• Call or email our Info Desk to reserve a space: 707-565-2608; mgsonoma@ucdavis.edu.

*Published with assistance from Zero Waste Sonoma

November 2022