Why Should I Compost?
- It keeps organics from going to our landfills, thereby reducing the amount of methane gas created.
- It saves money by replacing purchased soil amendments.
- It improves soil structure (such as reducing soil compaction) by loosening clay soil and feeding the soil microbes.
- It increases soil water saving capacity.
- It’s free or low cost!!!
What to Consider When Selecting a Home System
- How much time and effort are you willing to commit to maintaining your system?
- How quickly do you want to see results…ready to use compost?
- What type of organic materials will you be using?
- Where is your bin going to be located?
- How much money do you want to spend on a system?
- Will it be open air, or do you prefer an enclosed system?
Starting a Compost System
How quickly your organics produce compost depends on the four main components:
- The size of the material put in the bin
- How moist it is kept
- How often it is aerated
- The volume
- Size of materials
You will speed up decomposition by adding smaller chopped or shredded materials to your bin. - Moisture
Keep your bin as moist as a wrung-out sponge. The bacteria creating your compost, needs water to survive. If you can squeeze out water, your pile is too wet. - Aeration
The bacteria in your pile also need oxygen to survive. Remember to mix, lift or turn your materials. - Volume
The ideal size of a pile is 3 feet x 3 feet. Smaller piles tend to dry out quickly. The maximum pile size is 5 feet x 5 feet. These larger piles need to be aerated more often.
What Goes in The Pile?
Ideally, you want a 50% x 50% ratio by volume of greens to browns. But anything organic will decompose.
What are examples of “Greens”?
- Grass clippings
- Yard waste
- Vegetable and Fruit scraps
- Coffee filters and grounds
- Chicken manure (can make your pile hot!)
What are examples of “Browns”?
- Dried leaves
- Sawdust
- Newspaper
- Wood chips
- Straw
What DOES NOT Go into the Pile?
- Diseased plants
- Plants with severe insect infestation
- Ivy and succulents
- Bermudagrass & morning glory
- Cat and dog manures
- Meat and fish
- BBQ ashes
- Dairy products: Cheese, sour cream, butter, etc.
- Glossy paper such as magazines
- Plants treated with herbicides
Compost Tips
Gather all grass clippings and green yard waste but be sure to mix with the "brown" materials like leaves and shredded paper to add carbon. You will need both, but if you only add grass clippings your pile will compact and start to stink.
- Do not compost meat or pet droppings. Stick with food scraps and yard waste only.
- Avoid all pesticides and/or herbicide treated material.
- If you add weeds to your pile, make sure your pile is good and hot. It should be steaming hot, not just warm otherwise it may not kill the seeds.
- Turn your pile as often as you can. Each time you turn it, it will speed up the process.
- Keep your compost damp but not wet. As you add material to your pile make sure that each layer is moist as it is added. During the summer your pile will dry out and the composting process will slow down.
- Got too much material to compost? Make a second or third pile. Stop adding material to a pile that is underway and start a new pile. This will ensure you get a chance to use the compost this season.
- Add compost to your garden a few weeks before you plant. Let the compost have a chance to work into the soil. Try to mix it in and let it sit before you plant.
- Worms and most bugs are ok. No need to go crazy trying to keep bugs out of your compost.
- Since the compost process works best at temperature between 120 and 160 degrees Fahrenheit, composting in the warmer months is easier to do. If this is your first attempt at composting, it’s best to try in the summer.
- Your pile is ready to be used when you can no longer recognize the materials, and it smells “earthy”.
projectcompost.ucdavis.edu
Let’s Look at Bin Options
Garbage Can Composter
A garbage can composter is easy to build and inexpensive. You may use aluminum, or plastic can and that has a secure lid. These can be rodent resistant.
- Drill holes four to 6 inches apart all around the sides of the can, along with several holes on the bottom. This allows air movement and drainage of excess moisture.
- Optional: To aid with turning, place a piece of PVC pipe to the center of the can.
- Place several inches of sawdust, straw or wood chips to the bottom.
- Add your kitchen scraps, yard waste, etc.
Moveable Compost Bin
A moveable bin is inexpensive and easy to build. It can be used in areas with limited space. Inexpensive kits are available online under “Geo Bin”.
- Determine what diameter of bin you’d like. One that is 3-5 feet in diameter will need 10-16 feet of wire or plastic fencing.
- Bend the fencing into a circle and secure the ends. You may want to attach it to posts or stakes for stability. Make sure you are wearing protection from the wires!
- Add your kitchen and yard waste
Three Bin System
This system is designed for easy management. Those made with wire will produce compost more quickly. Depending on what materials you choose it may be a bit more expensive, however it is also more durable.
- Decide how wide and tall you want your system. Are the sides going to be constructed out of wood (pallets work well) or wire mesh?
- Divide your system into thirds, using dividers constructed out of mesh or wood, placing them parallel to one another.
- Place your kitchen and yard waste into an end unit. When the materials are 50% decomposed, move them to the center bin. The third bin holds the fully decomposed, ready to use compost.
Tumblers
Tumblers tend to take longer creating compost versus open -air bins, however they are a good option for those in urban areas who don’t have the space for an open-air bin. There are two important points about tumblers that you need to remember. The first is they dry out quickly, so moisture needs to be monitored, especially during the summer months. The second is you need to remember to turn them, stirring the compost beforehand, as the center tends to stay stagnant.
Worm Bin
Worm composting is great for those with limited space or who have kitchen scraps but not enough yard waste to warrant a larger bin.
- Purchase a 10-gallon opaque plastic tote. (Worms do not like light). Drill ¼” holes all over including the lid and bottom.
- Add shredded newspaper, paper from your home shredder (unless it is diamond shaped…or you’ll end up with paper mâché), coconut coir, shredded cardboard egg cartons. Spray water onto the bedding so it’s moist like a damp sponge…not wet!
- Add your worms. Composting worms are Red Wigglers (Eisenia Fetida). Do not use earthworms or night crawlers.
- Place your bin in an area where it receives bright indirect light. This will make your worms dive into their bedding.
- The next day, feed your worms kitchen scraps, including coffee filters and grounds. Feed as needed.
- Harvest the worm castings when the bin is 50% bedding, 50% castingsEXTERNAL IMAGE.
What is Hot or Rapid Composting?
You can speed up the compost process by following the rapid composting guidelines.
- Keep your bin size to 3 feet x 3 feet
- Keep your material size under 1 ½ inches
- Use equal volumes of greens and browns adding all materials once
- Turn your pile every three days, moving the outside material to the center
- Monitor the moisture of your pile keeping it about the same moisture level as a wrung-out sponge
- Use a thermometer to check the temperature in the center of your pile. You want it to reach 130-160 F. When the pile heats up over 140F, cool the pile by turning and mixing
- When the temperature of the pile drops down to 90F it is ready to use. However, it is recommended you let it cure for 2 weeks.
- Be sure to remove larger pieces of woody organic material prior to using
Compost Troubleshooting Guide
Symptom | Problem | Solution |
| Bad odor (rotten smell) | Too much moisture | Turn the compost or add dry, porous material |
Bad odor (ammonia smell) | Too much nitrogen | Add high-carbon materials like straw, sawdust, wood chips Turn the compost or make the pile smaller Turn the compost |
| Low compost temperature | Pile too small Too little moisture Too much moisture Too little air Lack of nitrogen Cold weather Particle size too large | Increase size, insulate sides Add water and turn the compost Turn the compost and mix in dry materials Turn the compost Mix in nitrogen source: grass clippings, manure, or organic nitrogen fertilizer Increase pile size or insulate pile with layer of straw or plastic Chip or grind materials |
| Pile is dry throughout | Not enough water; too much wood material | Turn pile and moisten material; add fresh materials; cover pile |
| Compost pile is damp and warm in middle but nowhere else | Pile is too small | Collect more material and mix the old ingredients into a new pile |
| Pest infestation: dogs, rodents, insects | Improper food scraps added Food scraps not covered | Don’t add meat, fats, bones or other animal products Place fruit and vegetable scraps in the center of pile, cover with soil. Use rodent-proof closed-air bins or compost with worms |
| Neighbor complains | Compost pile is ugly | Construct covered bin system to keep it neat |
| Worm bin smells bad | Not enough air circulation Improper food scraps Too much food | Add fresh bedding Remove meat, bones or other dairy products Feed worms less |
| Worms are dying | Not enough food Bin too dry Bin too wet Bedding is eaten; too many castings | Add food into bedding Moisten contents until slightly damp Add bedding Harvest castings and add fresh bedding |
| Fly infestation | Food exposed | Secure lid with latches Line bin with weather stripping Cover food scraps with bedding Cover worms and bedding with sheet of moist newspaper |
| Ant infestation | Food accessible | Coat legs of bin with a pest barrier Set legs in cans of water or mineral oil |
Advice to grow by . . . ask us.
UCCE Master Gardeners of Orange County
mgorange.ucanr.edu/Gardening_Hotline/ R11/2024
UC ANR is an equal opportunity provider and employer.
All information referenced from UCCE Master Composter Training Manual by the Master Gardeners of Placer County
April 2025
Website: pcmg.ucanr.org
UC Master Gardeners of Placer County are University of California Cooperative Extension (UCCE) ambassadors to the Placer County home gardening community. UCCE is part of the Division of Agriculture and Natural Resources (ANR) of the University of California. UC ANR is an equal opportunity provider and employer. UCCE Placer County: 2855 2nd Street, Auburn, CA 95603; (530) 889-7385