Resource library

The free sources this manual relies on, grouped by what they cover, with who publishes each one and what kind of claim it makes. Every link was fetched on October 26, 2026.

How to read this list

• Extension service means a university's public education arm (for example NC State Extension). Agency means a government body (for example EPA or a state department). Their guidance is advice for a typical household, and it differs between places and between sources; the chapters say where.
• Claim type says what kind of statement the source makes: a physical principle, a convention (what most guides say to do), a measured result, a regulation, a product fact, or one practitioner's method. A convention is not a law of nature.
• Where a source is a local rule (a city's bag rule, a state's bear guidance), it is an example of what to ask your own city, county or state, not a rule for you.

Free courses that cover the same ground

• Vermont Composting Short Course: University of Vermont Extension, extension service, a six-week course.
• NYC Master Composter Certificate Course: NYC Community Compost Network, nonprofit, city-funded volunteer training.
• Smart Gardening, Los Angeles County: county public works, local government, webinars and technique videos.
• Bokashi Academy: a bin maker's own course, so product-linked; read it as one maker's teaching.

The basics: decomposition, ratios and the science

• Composting at Home: U.S. Environmental Protection Agency, agency, claim type: convention.
• Compost Chemistry: Cornell Waste Management Institute, Cornell Composting Science & Engineering, extension service, claim type: physical principle.
• Compost Physics: Cornell Waste Management Institute, extension service, claim type: physical principle.
• Compost Microorganisms: Cornell Waste Management Institute, extension service, claim type: physical principle.
• Invertebrates of the Compost Pile: Cornell Waste Management Institute, extension service, claim type: physical principle.
• The Effect of Particle Size on Bioavailability: Cornell Waste Management Institute, extension service, claim type: research finding.
• Monitoring Compost Moisture: Cornell Waste Management Institute, extension service, claim type: physical principle.

Ratios and mixing

• C/N Ratio: Cornell Waste Management Institute, Cornell Composting Science & Engineering, extension service, claim type: physical principle (formula) with convention (30:1 target).
• Calculate C/N Ratio For Three Materials: Cornell Waste Management Institute, extension service, claim type: physical principle.
• Moisture Content: Cornell Waste Management Institute, extension service, claim type: physical principle.
• Backyard Composting of Yard, Garden, and Food Discards, AG-791: NC State Extension, extension service, claim type: convention.
• Composting, HGIC 1600 (Robert F: Polomski, Nancy Doubrava, extension service, claim type: convention.
• Making and Using Compost, G6956: University of Missouri Extension, extension service, claim type: convention.
• Chapter 2, Composting Fundamentals, Don't Bag It – Compost It: Texas A&M AgriLife Extension, Aggie Horticulture, extension service, claim type: convention (with physical principle).
• Small Scale Composting in the Low Desert of Arizona, AZ1632: University of Arizona Cooperative Extension, extension service, claim type: convention.
• Three Ways to Compost (Deborah J: Benoit). University of Vermont Extension, extension service, claim type: convention.
• Composting 101: NC State Extension, Extension Gardener, extension service, claim type: convention.

Hot and cold composting

• 40 CFR Part 503, Appendix B, Pathogen Treatment Processes: U.S. EPA regulation via eCFR (Office of the Federal Register), agency, claim type: regulation.
• Monitoring Compost Temperature: Cornell Waste Management Institute, extension service, claim type: convention.
• Composting in home gardens (Carl J: Rosen, extension service, claim type: convention.
• Home Composting: A Guide for Home Gardeners: Penn State Extension, extension service, claim type: convention.
• Backyard Composting, EB1784E, Home Garden Series (A: Bary, Craig Cogger, Dan Sullivan). Washington State University Extension, extension service, claim type: convention.
• Backyard Composting: WSU Whatcom County Extension, Master Composter/Recycler Program, extension service, claim type: convention.
• Backyard Composting in Utah: Utah State University Extension, extension service, claim type: convention.
• Home Composting: University of Illinois Extension, Knox County, extension service, claim type: convention.
• Do the rot thing: choosing and using a composting system, EM 9475: Oregon State University Extension, extension service, claim type: convention.
• Three methods for no-turn cold composting, EM 9480: Oregon State University Extension, extension service, claim type: convention.
• Home Composting Guide: New York State Department of Environmental Conservation, agency, claim type: convention.
• Home Composting: New York State Department of Environmental Conservation, agency, claim type: convention.
• Composting in Your Backyard: North Dakota Department of Health, agency, claim type: convention.

Bins and building plans

• Chapter 3, Composting Structures, Don't Bag It: Texas A&M AgriLife Extension, Aggie Horticulture, extension service, claim type: convention.
• Chapter 4, Building and Maintaining a Compost Pile, Don't Bag It: Texas A&M AgriLife Extension, Aggie Horticulture, extension service, claim type: convention.
• Compost tumbler suggestions: Oregon State University Extension, extension service, claim type: one practitioner's method (an extension specialist's own experience, labelled as such).
• Composting Series: Backyard Composting, Pub. 3838-L: LSU AgCenter, extension service, claim type: convention.
• How do you construct a compost pile? Iowa State University Extension and Outreach, Yard and Garden: extension service, claim type: convention.

Siting, climate and winter

• Composting: Overview, PlantTalk Colorado #1627: Colorado State University Extension, extension service, claim type: convention.

Worm bins

• Worms Can Recycle Your Garbage: NC State Extension, Rhonda Sherman, extension service, claim type: convention.
• Composting with Worms: Oregon State University Extension, Sam Angima, Michael Noack, Sally Noack, extension service, claim type: convention.
• Vermicomposting Puts Worms to Work: Penn State Extension, Mary Jo R. Gibson, Master Gardener, Columbia County, extension service, claim type: one practitioner's method (Master Gardener article on an extension site).
• Vermiculture: UC Cooperative Extension Master Gardeners of Orange County, hosted on UC ANR, extension service, claim type: convention.
• Composting in Small Spaces: UC Master Gardener Program of Contra Costa County, Lorraine Frey, extension service, claim type: one practitioner's method.
• Indoor Composting with a Worm Bin: NYC Compost Project / DSNY, city program, claim type: convention.
• Vermicomposting (Worm Composting) Tip Sheet: Thurston County Master Recycler Composters and WSU Extension, extension service, claim type: convention.
• Composting At Home: DC Department of Energy and Environment, agency, claim type: convention.

Bokashi

• Bokashi Composting: WSU Extension Kitsap County, extension service, claim type: convention.
• Bokashi Composting: A Faster, Easier Way to Turn Kitchen Scraps Into Garden Gold: N.C. Cooperative Extension, extension service, claim type: one practitioner's method.
• Home Organics Management: Bokashi: Regional District of Central Kootenay, B.C., agency, claim type: convention.
• Bokashi composting: Gardening at USask, nonprofit, on a university site, claim type: one practitioner's method.
• Exploring the use of bokashi as a soil fertility amendment in Northeast vegetable production systems: Northeast SARE, University of Vermont, Dana Christel and Dr. Josef Görres, research proposal summary, claim type: research finding (proposal only; no findings on this page).
• How to turn bokashi into soil: Bokashi Organko (Skaza), manufacturer; product facts only, claim type: product fact.

Trenches, sheet composting and in-ground digesters

• Trench composting: Gardening at USask, courtesy of the Saskatchewan Waste Reduction Council, nonprofit, on a university site, claim type: convention.
• Trench Composting – A Simple Method of Reusing Kitchen Waste: Nebraska Extension in Lancaster County, Sarah Browning, extension service, claim type: convention.
• Sheet mulching and lasagna composting with cardboard: Oregon State University Extension, Shannon Rauter and Len Sherp, extension service, claim type: convention.
• Green cone user guide: Banyule City Council, Victoria, Australia, city program; product-specific guidance, claim type: product fact (as relayed by a council).

Electric food recyclers

• Electric Kitchen "Composter" Confusion: BioCycle, Ron Alexander, R. Alexander Associates, trade journal; practitioner author, claim type: research finding (review plus author's trials).
• Debunking the Myth: Food Scrap Dehydrators Are Not Composters: Illinois Food Scrap & Composting Coalition (submitted by SWANCC and Seven Generations Ahead staff), nonprofit, claim type: definition.
• The Effect of Initial Carbon to Nitrogen Ratio on Kitchen Waste Composting Maturity: Azis, Choo, Suhaimi, Abas (Universiti Brunei Darussalam), Sustainability 15(7), April 2023, research, claim type: research finding.
• What do Food Recyclers actually do, and why do they matter? Mill, Scott Smithline, Head of Organics Policy and Research: manufacturer; product facts only, claim type: product fact.
• FoodCycler FC-50 product page: Vitamix, manufacturer; product facts only, claim type: product fact.

Tumblers and enclosed bins

• Home Organics Management: Tumbler Composters: Regional District of Central Kootenay, agency, claim type: convention.
• Compost Bins: Brooklyn Botanic Garden, BBG Staff, nonprofit, claim type: convention.
• NYC Outdoor Composting Guide: NYC Compost Project / DSNY, city program, claim type: convention.
• Guide to Urban Farming: Composting: Cornell Small Farms Program, extension service, claim type: convention.

Kitchen collection, fruit flies and liners

• Compost tips: City of Portland, Bureau of Planning and Sustainability, city program, claim type: regulation (local program rule) and convention.
• Fruit Flies: University of Kentucky Entomology, Michael F. Potter, extension service, claim type: physical principle (life cycle) and convention (control).
• Food Scraps & Yard Waste: City of Burnaby, B.C., city program, claim type: regulation (local program rule).
• Compostable Bags: Seattle Public Utilities, city program, claim type: regulation (local program rule).

Drop-off and curbside programs

• Curbside Composting requirements: NYC 311 / DSNY, city program, claim type: regulation.
• Curbside Composting: NYC Department of Sanitation, city program, claim type: regulation.
• DSNY begins enforcing curbside composting after pause: News 12 Brooklyn, Karina Gerry, news outlet; used only for enforcement status, claim type: regulation (status report).
• Food Scrap Drop-Off: NYC Department of Sanitation, city program, claim type: regulation (program rule).
• Food Waste Requirements: Seattle Public Utilities, city program, claim type: regulation.
• Understanding the Universal Recycling Law: Food Residuals Banned from Disposal in Trash: Vermont Department of Environmental Conservation, Solid Waste Program, agency, claim type: regulation.
• Four years into food scrap landfill ban, Vermonters are diverting just over half of food waste: Vermont Public, Corey Dockser, news outlet; status check, claim type: research finding (state estimate, reported).
• Short-Lived Climate Pollutants (SLCP): Organic Waste Reduction: CalRecycle, agency, claim type: regulation.
• Composting for Community: Institute for Local Self-Reliance, nonprofit, claim type: definition.
• Map of Community Composters: Institute for Local Self-Reliance, nonprofit, claim type: definition (directory).
• Food Scrap Drop-Off Site Locator: BioCycle, trade journal, claim type: definition (directory description).

Local rules on backyard bins

• Ordinance SO2025-0018160: Amendment of Municipal Code Sections 7-28-710 and 7-28-715 prohibiting restrictions on residential composting: Chicago City Council record on Chicago Councilmatic, agency record, third-party mirror, claim type: regulation.
• Chicago's New Composting Rules: What Landlords & Managers Must Know: KSN law firm blog (ksnlaw.com), Jessica Ryan, practitioner; law firm, claim type: regulation (secondary summary).
• Home Composting: DC Department of Public Works, Office of Waste Diversion, agency, claim type: regulation (program rule).

What goes in and what stays out

• 2: Composting, extension service, claim type: convention.
• How to Make Compost at Home: University of Maryland Extension, Home & Garden Information Center, extension service, claim type: convention.
• How to Begin: University of Illinois Extension, extension service, claim type: convention.
• Questions About Composting: University of Illinois Extension, extension service, claim type: convention.
• Can I Compost It? UF/IFAS Extension Sarasota County: extension service, claim type: convention.

Pet waste

• Composting Dog Waste: USDA Natural Resources Conservation Service (Alaska) and Fairbanks Soil and Water Conservation District, agency, claim type: one practitioner's method (field study method) plus agency guidance.
• Composting Dog Waste: UF/IFAS Extension Sarasota County, extension service, claim type: convention (secondary summary).
• Preventing Toxoplasmosis: Centers for Disease Control and Prevention, agency, claim type: convention (public health guidance).
• About Toxocariasis: Centers for Disease Control and Prevention, agency, claim type: convention (public health guidance).

Persistent herbicides

• Herbicide Carryover in Hay, Manure, Compost, and Grass Clippings, AG-727: NC State Extension, extension service, claim type: research finding plus regulation (label summary).
• Herbicide-contaminated compost and soil mix: What you should know: and what you can do about it, EM 9307: Oregon State University Extension Service, extension service, claim type: convention plus research finding.
• Can I use compost contaminated with clopyralid or other herbicides?: National Pesticide Information Center, agency, claim type: convention plus product fact.
• Bioassay Test for Herbicide Residues in Compost: Protocol for Gardeners and Researchers in Washington State: Washington State University Puyallup, extension service, claim type: one practitioner's method (consensus protocol).
• Registration Review of Pyridine and Pyrimidine Herbicides: U.S. Environmental Protection Agency, agency, claim type: regulation.
• Milestone herbicide label, EPA Reg. No. 62719-519: manufacturer, claim type: regulation (label language) / product fact.
• Aminopyralids: Restrictions for Grazing, Compost and Manure: University of Nebraska–Lincoln CropWatch, extension service, claim type: convention.
• Persistent Herbicide Information for Horse and Livestock Owners: Vermont Agency of Natural Resources, agency, claim type: regulation (state) plus research finding.
• Organic Matter and Soil Amendments: University of Maryland Extension, extension service, claim type: convention.

Compostable plastics and packaging

• BPI Compostability Certification: Biodegradable Products Institute, certifier, claim type: product fact / definition.
• How to Compost Certified Compostable Products at Home: Biodegradable Products Institute, certifier, claim type: product fact plus research finding (certifier's own study).
• Fluorinated Chemicals: Biodegradable Products Institute, certifier, claim type: product fact (certification rule).
• ASTM D6400-26, Standard Specification for Labeling of Plastics Designed to be Aerobically Composted in Municipal or Industrial Facilities: ASTM International, standards body, claim type: definition.
• ASTM D6868-21, Standard Specification for Labeling of End Items that Incorporate Plastics and Polymers as Coatings or Additives with Paper and Other Substrates Designed to be Aerobically Composted in Municipal or Industrial Facilities: ASTM International, standards body, claim type: definition.
• OK compost HOME: TÜV AUSTRIA, certifier, claim type: definition / product fact.
• 16 CFR 260.7, Compostable claims: Federal Trade Commission, via eCFR, agency, claim type: regulation (guidance codified in CFR).
• 16 CFR 260.8, Degradable claims: Federal Trade Commission, via eCFR, agency, claim type: regulation.
• History of California Solid Waste Law: CalRecycle, agency, claim type: regulation (summary).
• PFAS in Food Packaging: Washington State Department of Ecology, agency, claim type: regulation.

Health cautions

• Preventing Aspergillosis: Centers for Disease Control and Prevention, agency, claim type: convention (public health guidance).
• About Aspergillosis: Centers for Disease Control and Prevention, agency, claim type: convention.
• Gardening Safely With Aspergillosis: Soil, Compost and Mould Exposure: Aspergillosis Patients & Carers Support, aspergillosis.org, nonprofit, claim type: convention (patient guidance; UK context).
• Multidrug-resistant fungi found in commercial soil, compost, flower bulbs: University of Georgia, UGA Today, extension service; university news on a CAES study, claim type: research finding (commercial products, not home compost).
• Legionnaires' Disease Associated With Potting Soil: California, Oregon, and Washington, May–June 2000: CDC MMWR 49(34), agency, claim type: research finding (outbreak report).
• Legionella longbeachae and Legionellosis: Emerging Infectious Diseases 17(4), April 2011, CDC, agency journal, claim type: research finding (review).
• Legionnaires' disease fact sheet: NSW Health, New South Wales Government, Australia, agency, claim type: convention (public health guidance).
• Don't let Legionnaires' disease bloom this spring: NSW Health, agency, claim type: convention.

Manure

• 7 CFR 205.203, Soil fertility and crop nutrient management practice standard: USDA Agricultural Marketing Service, via eCFR, agency, claim type: regulation.
• Raw Manure under the FSMA Final Rule on Produce Safety: U.S. Food and Drug Administration, agency, claim type: regulation (farm rule; status).
• Wise Use of Manure in Home Vegetable Gardens: Penn State Extension, extension service, claim type: convention.
• Bulletin #2510, Guidelines for Using Manure on Vegetable Gardens: University of Maine Cooperative Extension, extension service, claim type: convention.
• Safely Using Manure in the Garden: University of Wisconsin–Madison Division of Extension, Wisconsin Horticulture, extension service, claim type: research finding (author's own).
• Using Manure in the Home Garden: Iowa State University Extension and Outreach, Yard and Garden, extension service, claim type: convention.

Wood ash, charcoal, sawdust and treated wood

• Managing Wood Ashes: UNH Cooperative Extension, extension service, claim type: convention.
• Are fireplace ashes good for my soil?: Oregon State University Extension Service, extension service, claim type: convention.
• Using Wood Ash in the Home Garden: University of Wisconsin–Madison Division of Extension, extension service, claim type: convention.
• Chromated Arsenicals: U.S. Environmental Protection Agency, agency, claim type: regulation / convention.
• Walnut leaves: Safe for composting?: Oregon State University Extension Service, extension service, claim type: one practitioner's method (a volunteer's answer).

Rodents, raccoons, bears and flies

• Composting in Bear Country: Vermont Fish & Wildlife Department, agency, claim type: convention.
• Protect Your Home from Wildlife: Colorado Parks and Wildlife, agency, claim type: convention.
• Living in Bear Country: Montana Fish, Wildlife & Parks, agency, claim type: convention.

Leaves and leaf mold

• Leaves Are Treasure, Not Trash: Penn State Extension, extension service, claim type: one practitioner's method (Master Gardener article on an extension site).
• Recycling your leaves: University of Illinois Extension, Flowers, Fruits and Frass blog, extension service, claim type: one practitioner's method.
• Leaf mold post, UGA Cooperative Extension Paulding County: University of Georgia Extension, extension service, claim type: one practitioner's method.
• Compost 101: Turning Fall Leaves Into Garden Gold: NC State Extension, Beaufort County, extension service, claim type: convention.

Grass clippings

• Recycling Turfgrass Clippings: Penn State Extension, extension service, claim type: research finding.
• Grasscycling: Let the Clippings Fall Where They May: University of Georgia Extension, extension service, claim type: research finding (summarized).
• Problem Materials: UF/IFAS Extension Sarasota County, extension service, claim type: convention.
• Killer Compost: Washington State Magazine, Washington State University, research paper; university magazine report, claim type: research finding.

Woody material and pine needles

• Using Arborist Wood Chips as Landscape Mulch: Linda Chalker-Scott, Washington State University Extension, extension service, claim type: research finding (review).
• Pine Needle Mulch: the Myths and Legends: NC State Extension, Lee County, extension service, claim type: research finding (summarized by an agent).

Finished compost: signs, curing and tests

• Testing for Finished Compost: Cornell Cooperative Extension of Tompkins County, Compost Education Program, extension service, claim type: convention (home test method).
• Compost Maturity Test: UF/IFAS Extension Sarasota County, extension service, claim type: convention (home test method).
• Compost: Woods End Laboratories, Solvita, manufacturer, claim type: product fact.
• Introducing STA Certified Compost: BioCycle (trade magazine), by Ron Alexander and Al Rattie, nonprofit/trade context for a US Composting Council program, claim type: definition.
• Composting: Suzanne Smith Hirrel, University of Arkansas Cooperative Extension, extension service, claim type: convention.

Using compost

• How to Use Compost in Gardens and Landscapes: Oregon State University Extension, extension service, claim type: convention.
• Using Compost in Colorado Gardens: Colorado State University Extension, extension service, claim type: convention.
• Organic Soil Amendments in Yards and Gardens: How Much is Enough?: Washington State University Extension, extension service, claim type: research finding / convention.
• Correcting too much compost and manure: University of Minnesota Extension, extension service, claim type: convention.
• Too much of a good thing? Urban gardeners may overdo compost: Oregon State University Extension, extension service, claim type: measured data (small study, reported in a news article).
• Fungus Gnats: University of California Statewide IPM Program, extension service, claim type: convention.

Compost tea

• The Myth of Compost Tea: "Compost tea is an effective alternative to traditional pesticides." Linda Chalker-Scott, Washington State University Puyallup: extension service, claim type: research finding (expert review).
• Compost Tea: Miracle Cure or Marketing Gimmick? Angie Cahill and Linda Chalker-Scott, WSU Puyallup: extension service, claim type: research finding (one field study).
• Compost Tea to Suppress Plant Disease: Vern Grubinger, University of Vermont Extension, extension service, claim type: research finding (summary).
• Recommendations for a Safer Compost Tea: USDA Agricultural Research Service, agency, claim type: research finding.
• On-farm Composting: Best Practices To Ensure On-farm Food Safety: LSU AgCenter, Charles Graham and Achyut Adhikari, extension service, claim type: convention (food-safety guidance).

Troubleshooting

• Make compost that really cooks: troubleshoot heat, odor and pests: Oregon State University Extension, extension service, claim type: one practitioner's method (extension specialist).
• Composting Troubleshooting Guide: Ward Upham, Kansas State University Research and Extension, extension service, claim type: convention.
• Compost Troubleshooting Guide: University of California Cooperative Extension, Napa County, extension service, claim type: convention.

Waste statistics

• National Overview: Facts and Figures on Materials, Wastes and Recycling: U.S. EPA, agency, claim type: measured data (modeled national estimate).
• Food: Material-Specific Data: U.S. EPA, agency, claim type: measured data (modeled).
• Yard Trimmings: Material-Specific Data: U.S. EPA, agency, claim type: measured data (modeled).
• 2019 Wasted Food Report: Estimates of generation and management of wasted food in the United States in 2019: U.S. EPA, agency, claim type: measured data (modeled from studies).
• From Farm to Kitchen: The Environmental Impacts of U.S. Food Waste: U.S. EPA Office of Research and Development, agency, claim type: research finding.
• From Field to Bin: The Environmental Impacts of U.S. Food Waste Management Pathways: U.S. EPA, agency, claim type: research finding.
• Food Loss (Food Availability (Per Capita) Data System): USDA Economic Research Service, agency, claim type: measured data (modeled).

Landfill methane and greenhouse gases

• Quantifying Methane Emissions from Landfilled Food Waste: U.S. EPA Office of Research and Development, agency, claim type: research finding (modeled).
• Composting: U.S. EPA, agency, claim type: measured data (summary).
• Waste Reduction Model (WARM) Version 16, Management Practices Chapters: U.S. EPA, agency, claim type: convention (model scope).
• WARM Version 13, Composting chapter: U.S. EPA, agency, archived, claim type: convention (model output).
• Mass balances and life cycle inventory of home composting of organic waste: Andersen, Boldrin, Christensen and Scheutz, Technical University of Denmark, research paper; author's accepted version, claim type: measured data (Danish study, small sample).

Household food scrap amounts

• Estimating Quantities and Types of Food Waste at the City Level: Darby Hoover, Natural Resources Defense Council, nonprofit, claim type: measured data.