Backyard composting can be a simple way to create your own compost at home. 

Compost Bins

Compost bins can be constructed from any combination of wood, wire, plastic, or concrete. The piles and bins illustrated below represent just a few of the most basic designs. Choose a design and materials to suit your needs, taste, and pocketbook. If you do not want to build your own bin, a wide variety of commercial compost bins are also available.

• Loose Pile—You can create compost without a bin by piling yard trimmings in one area. A loose pile is easier to turn but takes up more space than a bin and is not rodent-proof.
• Chicken wire/hardware cloth loop bin—this is one of the simplest and least expensive kinds of bins. You will need about 10 feet of chicken wire or hardware cloth and a few stakes. The ends of the chicken wire should be fastened together with wire or zip-ties and the sides should be attached to stakes to give it some stability. Once the pile is filled, the stakes can be removed.
• Wooden pallet bin—you can nail a few wooden pallets together to make a single compost bin. To make composting even easier, you might want to consider having two or three open wooden pallet bins, so that you can easily turn the compost from one bin to another. You can also create a bin system like this by zip-tying nursery flats together.
• Plastic hoop bin—The City of Davis Public Works Department offers these compost bins for $10 to Davis residents in single-family homes. To get a composting bin you can take the online compost class.

Adding Materials to Your Pile

You can add yard trimmings to your pile at any time. Here's a few things to keep in mind:

• You might want to keep roses and other plants with thorns out of your compost pile to avoid getting scratched while turning your pile or harvesting compost.
• Keep diseased plants and invasive weeds out of your compost pile. While these materials can go into your organics cart, your backyard compost pile will not get hot enough to kill the weed seeds and plant diseases. The materials in your organics cart are sent to an industrial composting facility nearby where the temperatures reach high enough to kill seeds and disease organisms. Learn more about the Yolo Landfill composting facility.
• To prevent pests, you may want to consider keeping food scraps out of your pile. Adding food scraps makes your pile more attractive to rodents, raccoons and other creatures. If you add food scraps, make sure you turn your pile every week, keep your pile moist and make sure that food scraps are never more than 10% of the total volume of the pile.
• In order to help things compost quickly and make it easier for you to turn your pile, chop things up into small pieces (about 12" long) before adding them to the pile. The small items are, the faster they will decompose.

Maintaining Your Compost Pile

Turn the pile: For fast results and for a healthy aerobic compost pile, remember to turn the pile once a week.

Maintain moisture: Add water to your pile if it starts to dry out. A pile should always be kept moist. There is a simple test to make sure that your pile has enough water. Grab a handful of the material from your pile and squeeze it tightly in your fist. If your pile has the right amount of moisture, the material will clump together and there will be a few drops of water in your hand. If the material is too dry and will not clump together, you need to add more water. If the material is too soggy and drips water when squeezed, you may want to stop adding water for a while, turn the pile more frequently and maybe add more dry material (dried grass or straw).

It will take 3 to 6 months for your pile to turn into compost. During this time, you can continue to add more material to the pile, just be aware that the material added later will not be ready at the same time as the first material you added.

Harvesting Your Compost

You can tell that the material in your pile has turned to compost when you can no longer recognize it. The material will undergo a transformation, and instead of looking like the materials you incorporated into your compost pile, the materials will take on a soil- or humus-like appearance. When the majority of the pile seems to have composted, you can use a seed-planting tray to screen out the unfinished bits. The larger pieces can be tossed back into the pile for additional composting. When you have collected all the compost you should to spread it out on a tarp and leave it exposed to the air and sunlight. Drying out the material will work to cure the compost. It will also make this material easier to spread.

Common Ways to Use Compost

Soil Amendment: Finished compost can be turned into the soil as a soil amendment. As much as six inches of compost can be added to your soil each year. When used as a soil amendment, compost reacts with soil to slowly release both plant nutrients and essential trace elements. Compost can be turned into the soil in the spring in preparation for planting. It can also be spread on soil at the end of the gardening season and allowed to leach into the soil. If only a small amount of compost is available, it can be incorporated in the seed furrow, or a handful can be added to each transplant hole of annuals, perennials, or vegetables. Large amounts of compost can be used to plant trees, shrubs, and vegetable gardens, or to repair or replace lawn areas.

Mulch: Compost is not a typical mulch, yet it can be applied in the same ways that mulches are used. Compost is a stable product that will not deprive your soil of nitrogen. Spread compost two to six inches thick around plants, trees, shrubs, and exposed slopes. This will deter weeds, prevent crusting, curtail erosion, attract earthworms, and conserve water.

Potting Mix: Finished compost can be combined with equal parts of sand and soil to create an excellent potting mix. The compost should be screened to ensure that only fine particles are used in the mix. A simple screen can be made of ½-inch or other small-gauge fencing material and a wooden frame.

Want to learn more about composting?

City of Davis Online Compost Class: The City of Davis offers an online composting class. All Davis residents in single-family homes that complete the quiz with 70% accuracy or better (at least 20 of the 28 questions answered correctly) will qualify to purchase a GeoBin backyard composting bin from the City for $10.

For More Information

• California Department of Resources, Recycling and Recovery (CalRecycle)
• U.S. EPA

Properly composted food scraps can turn into an excellent fertilizer. However, composting food scraps in a regular backyard compost bin can be tricky. If done incorrectly, backyard composting of food scraps can attract some potential pests (rats, mice, raccoons and opossums). Fortunately, there are three simple ways to compost your food scraps without fear of attracting potential pests.

Please keep in mind that all three of these methods are ONLY for composting fruit and vegetable trimmings, bread, rice, pasta, tea bags, coffee grounds, coffee filters and other such materials. Do NOT attempt to compost meat, fish, dairy products, pet waste or greasy food through these methods. These items can attract pests and cause problems during composting.

You CAN place meat, fish, dairy, fruits and vegetables, breads, etc. in your organics cart for composting--those materials are sent to a professional compost facility that operates at high temperatures and is able to avoid pests and other pathogens.

Option #1: Worm Composting

Vermicomposting, a.k.a., worm composting, is the practice of using worms to compost your fruit and vegetable trimmings. The goal of worm composting is to create the ideal environment for worms to thrive so they can efficiently decompose the material you feed them. Worm composting is simple. You need a box, bedding, fruit and vegetable trimmings, and worms.  More detailed information about worm composting is provided in the drop-down menu below.

Option #2: In-Ground Composting

This is perhaps the simplest and most pest-free method of composting food scraps.  Just bury your food scraps at least 8 inches deep in your garden. Garden soil provides a natural barrier that keeps out flies and other pests, and holds in moisture and odors. If you have dogs that like to dig in your garden, this approach may not be the best for you.

Food scraps can be buried in empty areas of vegetable and flower gardens, or in holes outside the drip line (below the ends of branches) of trees and shrubs. Use a shovel or post hole digger to dig a hole or trench about 1 foot deep. Add 2 to 3 inches of food scraps to the hole. Chop and mix scraps into soil, then cover the food scraps with at least 8 inches of soil to keep pests out.

Check occasionally for signs of digging by rodents, dogs or other pests. If you see signs of digging, it may be better to switch to a digester or worm bin.

Food scraps may take from 1 to 6 months to decompose depending on the season, moisture, soil and the type of food scraps that are buried. Seeds and small seedlings may be planted on top of buried food scraps immediately. Large transplants should not be planted until the food has decomposed. Do not bury more food scraps in the same place until the first scraps have been fully composted.

Option #3: Composting with a Food Digester

Another option for composting food scraps is using a homemade food digester. You can make your own using a galvanized metal garbage can (a 32-gallon sized can works well). The can should have a tight-fitting lid. Drill or punch about 20 drain holes, 1/4 or 3/8 inch diameter, in the bottom of the can. Drill 20 more holes in the sides of the can, but only in the lower third, which will be covered by soil.  TIP: if you drill from the inside of the bin to the outside, you won't have to worry about sharp, jagged metal around the drainage holes inside your food digester--the sharp edges will be pointed outwards into the soil.

It is very important to make sure that the lid fits snugly on the can to keep raccoons and other pests out. If needed, a bungee cord or rope can be attached to the lid handle and the can handles to secure the lid.

Dig a hole at least 15 inches deep in a well-drained area of your yard and set the can into the hole. The can should be 1/3 to 1/2 buried in the soil—none of the holes you drilled should be visible above the soil. Push the soil back in around the sides. Your new food digester is ready to use! You do not need to add worms to your digester—worms will find their way into the digester through the holes and will help break down the food scraps.

You can collect your food scraps in a container in the kitchen and place the food scraps in your food digester whenever is convenient for you--every day, once or twice a week. Be sure the digester lid is on tight after adding the food scraps.

Harvesting the Compost From Your Digester

Depending on your household’s food habits and how large your digester is, the digester may fill in 4-12 months. After the digester has been established for at least 3 months, the first materials that you added should be at least partially composted. You can harvest compost from the digester when it is full or at any time you wish after the first 3 months. While harvesting compost from your digester, watch out for the jagged metal around drainage holes.

Harvesting Option 1: Shovel out the contents of the digester.  Place un-composted material back in the digester for further composting.  Mix the compost with some soil, lay it in the sun and wait for it to dry.

Harvesting Option 2: This method essentially uses the food digester as a fermentation vat by breaking down your food scraps into smaller, manageable amounts. When the digester gets full, or whenever you feel like emptying it, shovel out the contents of the digester (fully composted, partially composted and fresh food scraps) and follow the instructions for in-ground composting.

Food Digester Trouble-Shooting

If you have problems with cockroaches, using a homemade food digester may not be a good composting method.  The food digester can serve as a breeding ground for cockroaches unless managed very carefully.  If you have cockroach problems, be sure to harvest your food digester as soon as you notice cockroaches inside or around the digester and wash the digester out thoroughly after harvesting.

The best way to keep odors and fruit flies at a minimum in your homemade digester is to make sure the digester lid is always tightly closed. If necessary, tie the lid handle to the handles on the sides of the digester can to hold the lid on. Also, be sure to keep meat, fish, dairy and greasy food scraps out of your digester. They will smell bad and attract animals, so it is better to put them in the organics cart.

 If flies and odors are still troublesome, stir in leaves or sawdust to keep the food scraps aerobic. When adding more food scraps, you can also cover fresh food scraps with leaves, sawdust, straw or shredded newspaper to exclude fruit flies. If you prefer to use grass clippings as a covering material, first leave them in the sun to dry out and turn brown. Keep in mind that adding dry material each time food scraps are added will make your digester fill up faster. Another way to manage flies in your food digester is to hang strips of fly paper on the inside of the digester lid.

The inside of the digester may have a slightly unpleasant smell and some fruit flies—the goal is to make sure that the outside of the digester does not smell or have flies. Once a healthy worm population is established in the digester, they will help reduce odors by aerating the food scraps.

More Information

• Worm Composting Flier (PDF)  
• City of Davis Composting Video:  As the Worm Turns: Vermicomposting Basics (12 minutes)

Let Worms Eat Your Kitchen Waste

Another method of composting, separate from the backyard bin or compost pile method, is known as vermicomposting, a.k.a., worm composting. This is the practice of using worms to do your composting. Worms are macroorganisms that feed on your fruit and vegetable trimmings, and decompose them for you. The goal of vermicomposting is to create the ideal environment for worms to thrive so they can efficiently decompose the material you feed them. Worm composting is simple. You need a box, bedding, fruit and vegetable trimmings, and worms.

The Worm Bin

You can either buy a worm bin or make your own. An opaque plastic storage box purchased from a local retailer can serve as a great worm bin. Look for a bin that is relatively square. A long, thin, plastic storage bin that fits underneath a bed has a lot of surface area and will not provide your worms with any thermal protection. In a more square-shaped bin, your worms can migrate to the interior of the bin if the outside temperatures become too hot or cold and the surrounding bedding can provide some thermal insulation for them.

A tight-fitting lid is essential to keep pests out and protect the worms. The worms will not escape from their box--they are not attracted to light; hence, they migrate toward the center of their box—but you will need to make sure there are no gaps around the rim of the lid or any holes larger than 1/16 inch so that flies cannot access your worm bin and produce maggots.

Drill 10-20 small holes (no larger than 1/16 inch) in the lid of your worm bin so the worms receive fresh air. Drill another 10-20 holes into the bottom of your worm bin to allow excess moisture to drain out of the worm bin (this drainage, or "worm tea" is an excellent liquid fertilizer).

Locating Your Worm Bin

Composting worms prefer temperatures from 55°-77°. They reproduce and compost the fastest when the weather is warm, so if you have your bin outdoors, keep in mind that the worms will not compost food scraps as quickly during the fall and winter as they do in the spring and summer. Also, if your worms are kept outside, be careful not to freeze or overheat them. Worms are susceptible to high temperatures and should never be placed in the sun. If your worm bin receives any sunlight at all, the heat from the sun can build up in the bin, creating a greenhouse effect and killing all of your worms.  If your bin is outside, keep it in the shade of a tree or bush during the hot summer months. Do not place the bin on concrete or asphalt—on a hot day the radiant heat from the paved surface can kill your worms. If your bin is outside in the wintertime, place it in a protected area close to your house so that your worms will not freeze.

You may want to move your worms into the garage during the winter to protect them from freezing temperatures. If you are using a plastic storage bin as a worm bin, get an extra bin of the same size, fill the bottom with shredded newspaper, and place your worm bin inside the other bin to prevent any liquid (known as "worm tea"--an excellent fertilizer) from leaking onto your garage floor.

The Bedding

Common bedding materials include shredded newspaper, corrugated cardboard or coarse peat moss. Worm boxes should be filled to the top with bedding to provide the worms with a place to live. Just as a fish tank needs to be filled with water, the worm bin must be filled to within 2-3 inches of the top with bedding.

Shred paper through a vertical shredding machine (do not use cross cut paper shreds) or tear paper into 1/2 inch strips or smaller. Bedding material should be thoroughly moistened by soaking it in water for several minutes. Squeeze out the excess water before adding bedding material to the worm bin. It will take a LOT of paper to fill a worm bin. Add a handful or two of soil to provide grit that will help the worms digest food particles.

The Worms

Red worms, also known as red wigglers, are the best for vermicomposting. They thrive on organic material such as fruit and vegetable trimmings. Red worms are not the same as earthworms or night crawlers, which need mineral soil to survive.

One to two pounds of worms are needed to start a worm bin. Worms regulate their own population based on how much food is available. In other words, if they have a lot to eat, they increase their population. If food is scarce, their population decreases until the food supply increases. Worms reproduce very quickly. It is estimated that eight worms can multiply to 1,500 worms in six months. Once your system is established, there will be plenty of worms to help your friends get worm bins started.

Locally, red wigglers are sometimes available through UC Davis Project Compost (cce@asucd.ucdavis.edu) and often through local garden and hardware stores.

Feeding the worms

Worms will eat fruit and vegetable peelings, coffee grounds and filters, tea bags, rice, pasta and bread. Treat your worms as vegans and do not feed them any meat, dairy products, greasy foods, salad with dressing or pasta with a meat sauce. Be careful adding acidic material to your worm bin—coffee grounds and citrus scraps are tasty to worms, but too much acidic food can kill them. If your worms are avoiding the coffee grounds or citrus scraps in your worm bin, stop adding acidic material.

Be sure to bury your food scraps in the bedding to discourage molds and fruit flies. Never leave food on top of the bedding. Bury the food in a different corner of the bin at each feeding. Before feeding your worms, check to see if they've eaten the food you gave them last time. If they have eaten more than 60% of what you gave them, you can feed them a little more food. If they have not eaten most of the food from the last feeding, wait until they have eaten most of it before feeding them again. Do not overfeed your worms! Too much food in a worm bin can cause odors and may create an unhealthy environment for your worms.

You will need to add more bedding every few months as the worms eat the bedding as well. Always moisten the bedding before adding it to the bin. Always make sure there is enough fresh bedding to provide at least 2 inches of cover over the food scraps in the worm bin. If the food scraps are exposed, flies may gain access to the food and your bin may develop maggots. 

If you develop maggots and/or flies in your bin, add more bedding to cover exposed food scraps with fresh bedding. Check to see if there are any holes in the top of your bin that are large enough for flies to get in (any hole larger than 1/16 inch). Check for holes in the side or the bottom of your bin where flies may be able to access and lay eggs directly into your bin. Cover unwanted or large holes with duct tape and wait for the maggots to pupate, turn into flies and leave. Do not spray pesticides into or around your worm bin.

The Harvest

After a few months, you will notice that the original bedding is disappearing and is being replaced with rich, dark worm compost. When you have at least an inch of worm compost at the bottom of your worm bin you can harvest it.

To harvest the compost, put your worms on a diet; let them eat all the food in their bin. Then, place food in one corner of the bin. By the next day, most of the worms will be on that side of the bin eating. Remove the worm-free side of the box and set it aside. Spread the remaining contents across the bottom of the worm bin and refill the bin with fresh bedding. It's not a good idea to harvest the entire bin at once since worm cocoons and young will be hidden in the bedding and compost. Harvesting can also be stressful for the worms, so it's a good idea to leave some of them in the bin during harvest.

When scooping the contents of the worm bin, you probably noticed worms, some food and bedding still mixed in with the compost. Most people prefer to separate the compost before using it. To do this, place the contents that you removed from the worm bin in a pile on a flat surface. The worms will bury themselves deep in the pile to avoid light, so you can scrape off materials from the side of the pile a little at a time. Place the un-composted bedding, food and any worms you find back inside the worm bin.

Lay the worm compost out in the sun to cure and dry. Once the compost has been cured in the sun, it can be added to your garden—a homemade, natural fertilizer!  If any fresh food scraps you fed your worms contained seeds, the seeds are likely still viable and may sprout in the worm bin or in the finished compost.

Trouble Shooting Guide for Worm Composting

More Information

• More information about worm composting can be found on the CalRecycle web site.
• Copies of Mary Appelhof's book Worms Eat My Garbage (1982) are available for loan at the Davis branch of the Yolo County Public Library.
• Locally, red wigglers are sometimes available through UC Davis Project Compost (cce@asucd.ucdavis.edu) and local garden and hardware stores.

Grasscycling Brochure (PDF)

What is Grasscycling?

Grasscycling is the natural recycling of grass by leaving clippings on the lawn when mowing. Grass clippings will quickly decompose, returning valuable nutrients to the soil.

Grasscycling saves time, money, and protects the environment. Mowing time is reduced since the bagging and disposal of clippings is eliminated. Grass clippings add beneficial organic matter to the soil, which provides free fertilizer and produces healthy, green lawns. Grasscycling reduces the need for turf grass fertilizer and water requirements, which can minimize toxic runoff entering storm drains and polluting lakes, creeks and rivers.

Watering

Many people treat their lawns like a “crop”: they over water and over fertilize their lawns to encourage excessive growth. The “harvested crop” (grass clippings) is then bagged and disposed. Proper mowing, watering and fertilizing practices result in more moderate turf growth, yet still produce a healthy, green lawn. Grasscycling can be practiced on any healthy lawn as long as the following turf management guidelines are followed.

Turfgrasses vary in their need for water. Most grasses in California need about 1 inch of water every 5 to 7 days in the growing season and much less during slow growth months. Lawns watered too frequently tend to develop shallow root systems which may make them more susceptible to stress and disease. Deep, infrequent watering produces a deeper, extensive root system which enables turf to resist disease and stress. Over-watering is not only wasteful, it also causes lawns to grow faster and requires more mowing. The best time to water is early in the morning, as less water is lost due to evaporation. Try to avoid watering in the evening because prolonged damp conditions may encourage disease development.

Check your irrigation systems regularly to avoid water runoff and over-spraying, especially if the lawn is on a slope. Look for broken, tilted, or clogged sprinkler heads, and adjust to ensure even coverage. Remember to adjust your irrigation timer seasonally to match the water needs of the turf.

Fertilizing

Proper fertilization is essential in maintaining a healthy lawn. However, over-fertilization can weaken a lawn by causing excessive and succulent top growth. For moderate, even growth, use a combination of fast acting fertilizers (ammonium nitrate, ammonium sulfate, or urea) and slow release nitrogen sources such as sulfur-coated urea, urea formaldehyde, IBDU or organic fertilizers. Avoid using large quantities of fast acting fertilizers. These fertilizers produce very fast growth for short periods.

Regardless of the grass type and its fertility needs, as a general rule, your lawn will be healthier with smaller quantities of fertilizer applied more frequently rather than larger amounts applied less frequently.

Mowing

Proper mowing is required for successful grasscycling. It is best to cut grass when the surface is dry, and keep mower blades sharp (dull blades can shred grass and create a   potential entryway for disease). Follow the “1/3 rule:” mow the lawn often enough so that no more than 1/3 of the length of the grass blade is removed in any one mowing. Proper mowing will produce short clippings that will not cover up the grass surface. You may have to cut the lawn more frequently, or double cut, when the lawn is growing fast, such as in the spring, but much less when the turf is growing slowly. Additionally, raising the mowing height in the summer encourages deeper roots and protects grass from drought and heat damage. Check out the chart below for recommended mowing heights.

You can grasscycle with almost any mower. Refer to your owner’s manual or contact a lawn mower dealer to learn if you can safely grasscycle with your existing mower, or if you need to purchase a retrofit kit. Mulching or recycling mowers make grasscycling easy by cutting grass blades in to small pieces and forcing them into the soil. You may also want to consider purchasing an electric mulching mower to reduce air pollution.  

Frequently Asked Questions

Does grasscycling cause thatch build-up?

No. Research has shown that grass roots are the primary cause of thatch, not grass clippings. Thatch is composed mainly of roots, stems, rhizomes, crowns, and stolons. These plant materials contain large amounts of lignin and decompose slowly. Grass clippings are approximately 80-85% water with only small amounts of lignin, and decompose rapidly. Some grasses such as bermudagrass and kikuyugrass are more thatch-prone than others.

A small amount of thatch (approximately 1/2 inch) is actually beneficial to a lawn, providing insulation to roots and serving as a mulch to prevent excessive water evaporation and soil compaction. It may also create a cushioning effect for lawn play.

Does grasscycling spread lawn disease?

No. Improper watering and fertilizing are the primary cause of disease spread. If an accommodating environment for turfgrass disease is present, infestation will occur whether clippings are collected or not.

Will grasscycling make my lawn look bad?

No. If a lawn is properly mowed, watered, and fertilized, grasscycling can actually produce a healthier-looking lawn. It is important to cut the lawn frequently to produce small clippings that will fall between the standing blades and decompose quickly. However, if a lawn is not cut frequently enough and long clippings are left on the lawn, it may produce a “hay-like” look which can be unsightly.

Are there alternatives to grasscycling?

Yes. Grasscycling is not feasible in every situation. Prolonged wet weather, mechanical breakdown of mowers, or infrequent mowing are situations where grass clippings should probably be raked up since an excessive volume of clippings may be generated. But do not throw the clippings away! Grass clippings are an excellent addition to a backyard compost pile. Clippings can also be used as mulch to provide weed control and prevent moisture loss around flower beds, trees and shrubs. Do not mulch with clippings from an invasive grass, such as Bermuda grass, or with a grass where herbicides have been recently applied.