Wa182

Wisconsin Department ofNatural Resources

PUB-WA-182 2005

HOME COMPOSTING

The Complete Composter

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A Burning Issue

Burning leaves and brush is declining. Peoplerecognize the value of these materials for mulchor compost. They also realize that burningpollutes the air, creates fire hazards and can bea health risk and nuisance to neighbors. Stateair quality and fire control rules restrict back-yard burning and many communities prohibitit entirely.

Wisconsin’s Recycling Law

Each year over 300,000 tons of yard materialsno longer go to landfills or incinerators inWisconsin. Valuable space and resourceshave been saved since 1993 when the statebanned leaves, grass clippings, garden debris,and twigs, brush and branches (6” in diam-eter or smaller) from going to these disposalsites.

Although many communities provide collectionfor yard materials; the most economical way tohandle these materials is to compost them athome. Home composting saves money on soilamendments and improves your yard andgardens. Municipalities save too with reducedcollection costs.

(Note: stumps, roots or shrubs with intact root ballcan still be landfilled or sent to incinerators whichburn solid waste to recover energy.)

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Compost Systems. . . . . . . . page 4

“Hot or Cool” composting systems—whichapproach is better for you?

Food Scrap Composting. . . . page 6

What food scraps can you compost? Includesinformation on soil incorporation,

composting, andvermicomposting (wormbins).

Piles, Pits, Bins and Barrels. . page 7

What composting bin design will work for you?

Commonly-Asked Questions. . page 16

Answers to questions on composting pineneedles and oak leaves, odors, pests pesticides/herbicides, and other troubleshooting tips.

In This Brochure...

You will find information about differentcomposting methods as well as the types ofmaterials recommended for home composting.If you have questions about your current homecomposting or you are interested in compostingadditional materials, this brochure is for you.

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Hot Composting

A “hot” compost pile breaks down yard materi-als rapidly. You build a “hot” pile all at once(in a batch). The microbes on the yard materi-als multiply and are the workhorses of thecompost pile. Give the microbes a mix ofcarbon and nitrogen foods, water and oxygenand they will multiply and heat your pile. Thepile may reach 140˚ F or more, but to avoid lossof nitrogen (and associated ammonia odor) andoptimize the decomposition rate, you generallydon't want it hotter.

Hot compost piles require periodic “turning” tomix materials, allow oxygen to circulate, andkeep temperatures from getting too high. Inspring through fall, turn materials every 1 to 2weeks if using an enclosed bin, or every 2 to 3weeks if using a pile or open top bin. Add wateras needed to keep the materials slightly moist.Materials will become inactive if they are toodry. Overly wet materials will not allow aircirculation, and will produce undesirable odors,along with chemicals that aren't good for yourplants. A ”hot” pile can make finished compostin 2-6 months.

Hot composting is ideal for a household that haslots of yard materials, has limited space for acompost pile, wants a finished product in a shortamount of time, and is willing to actively workthe material. Food scraps can be buried 8-10inches into the center of the material or coveredwith a layer of dried leaves, hay or other carbon.Many communities regulate composting foodscraps. Always check with your local communitybefore composting your food scraps.

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Cool Composting

“Cool” composting is the laid back way torecycle your yard materials. A “cool” pile isbuilt a little at a time or all at once but withlittle turning. Always put a layer of carbon (i.e.leaves or hay) on the top to control odors.

A "cool" compost pile remains cool because: 1)it contains little or no green materials, 2)moisture isn't added, so sometimes, the materi-als may dry out, and 3) it isn't turned, so lowoxygen is available, and excess moisture isn't

driven off very fast. All of theseconditions result in slowcomposting. You may turn itnow and then or let it sit. Itmay be necessary to occasion-ally turn the materials, if odorsdevelop due to green materials

being added or the materials becoming toomoist. Finished compost can take 1 – 2 years.

In a “cool” compost pile, grass clippings andother nitrogen materials should be mixed withother bulky materials like leaves or straw. Becareful what you add to a “cool” pile. Do notadd diseased plants, or any portion of invasiveplants or their seeds, as high enough tempera-tures may not be reached to destroy the diseaseor viable parts of plants and their seeds.

Food scraps can be added to enclosed bins andmust be buried 8-10 inches into the center of thematerial or covered with a layer of dried leaves,hay or other carbon. Many communitiesregulate composting food scraps. Always checkwith your local community before compostingyour food scraps.

Cool composting is ideal for a household thatneeds to manage material, has enough space toallow material to sit for 1-2 years, and wants toput minimum work into managing their yardmaterials.

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Food Scrap Composting

Food scraps may be composted in three ways:incorporation into the soil, composting andworm bins.

In many communities there are public healthordinances which regulate food wastecomposting. Always check with your localcommunity before attempting to compost yourfood scraps.

Soil incorporation

Soil incorporation is the simplest method ofcomposting food scraps. Dig a hole or trench,chop the food scraps and mix them into thesoil, and then cover them with at least 8" ofadditional soil.

DO NOT bury foods such as meat, bones, dairyproducts, or oils. They will attract animals andother pests.

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Hot or Cool Composting

Food scraps should only be added to enclosedbins using the hot or cool method. They mustbe buried into a compost pile (8-10 inches) orput on an enclosed pile and covered with 8-10inches of carbon materials (leaves or straw, etc.)Add only uncooked vegetable scraps, neverscraps containing oils, meats, bones, or dairyproducts. Keep the pile enclosed in a bin to helpkeep out animals.

What food scraps can I compost?

YES: fruits and vegetables, such as apples(peels and core), cabbage, carrots, celery, coffeegrounds (and filters), eggshells, grapefruit,lettuce, onion peels, orange peels, pears, pine-apple, melon rinds, potatoes, pumpkin shells,squash, tea leaves, tomatoes, turnip leaves, etc.

NO: dairy and meat products, including butter,bones, cheese, chicken, fish scraps, lard, may-onnaise, meat scraps, milk, sour cream, andyogurt. Do not compost foods containing oils orfats such as peanut butter, salad dressing,margarine, and vegetable oil.

Piles, Pits, Bins and Barrels

No matter what composting method you use(hot vs. cold, or pile vs. open bin vs. enclosedbin) decomposition will occur faster if thematerials are reduced in size down to about 1/2inch. It's important that all the materials arenot reduced too small, as this will inhibit aircirculation, and very frequent turning will berequired to keep the microbes supplied withoxygen.

Too much moisture or green material (grassclippings) may cause odor problems. To mini-mize odors, mix in some leaves or bulky or-ganic material and turn the pile more fre-quently to let air inside.

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“The Pile”

The pile is not a structure, however manypeople use this composting method. Pile leavesand grass into a corner of the yard and naturedoes its work.

The pile can be used for either a cool or hotcomposting. DO NOT ADD FOOD SCRAPS tothis open pile!

Snow fence bin

Bins made withprefabricated snowfencing are popu-lar because theyare simple tomake and easy tomove and store.To build this bin, buy the appropriate length ofprefabricated fencing (a 64 cubic foot bin wouldbe 16' long and 4' high), and fasten two-by-fours to the corners to form a stable square bin.A bin 4' x 4' x 4' (64 cubic feet) may keep thecompost pile active during the winter months.

A snow fence bin can be used for either a coolor hot composting.

Woven wire bin

This simple, economical bin requires only alength of woven wire fencing and a few minutesof time to construct. Multiply the diameter ofthe compost heap by 3.2 to get the length of

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fencing to buy. Fasten the ends with wire orthree or four small chain snaps (available athardware stores) to make a circle. To turn thematerial in the bin, simply open the bin up,move it, and turn the material back into thebin at its new location. To make the bin morestable, attach the sides to posts. To keep thecompost from freezing during the wintermonths, use a piece of woven wire with a 4'height and approximately 16' long and overlapends by only about 9" to make a 41/2' diameterbin with a volume of about 64 cubic feet.

A woven wire bin can be either a cool or hotcomposting structure.

Wooden pallet bin

Old wooden pallets are an inexpensive, readilyavailable building material. Pallets can easilybe wired together to form a bin. In areas wherethe soil is a heavy clay, consider using a palletto form the bottom of the bin and keep materi-als up off the ground for better drainage.Construct bins with removable fronts or sides sothat yard materials can be easily turned with apitchfork. Wire mesh can be substituted forwooden sides to increase air flow. Covered binsallow protection from heavy rains.

A wooden pallet bin can be either a cool or hotcomposting structure.

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To make the structure more attractive considerpainting the bin with an outdoor latex paint orplant climbing plants around the outside of thebin.

Barrel/drum composter

A barrel or drum composter generates compostin a relatively short period of time and providesan easy mechanism for turning. This methodrequires a barrel of at least 55 gallons with asecure lid. Be sure it wasnot used to store toxicchemicals.

Drill 6-9 rows of 1/2 inchholes the length of thebarrel to allow for aircirculation and drainageof excess moisture. Placebarrel upright on blocks toprevent excessive rusting.To make a rotating barrelgo to www.uwex.edu/ces/shwec for BarrelComposter.

Fill 3/4 full with material. Every few days, turnthe rotating barrel or place the plain drum onits side and roll it around the yard to mix andlet air into the compost. The compost should beready in two to four months.

This is an easy system for city dwellers wherethere is a small amount of material. Thisrolling barrel design is one of the easiest toconstruct at home. Because of the small size ofthe structure, yard materials in the drum willusually freeze during a Wisconsin winter.

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Three-chambered bin

This efficient and durable composter yieldsquick results. It works like an assembly linewith three batches of compost in different stagesof decomposition. Material is started in the firstbin and allowed to decompose for 3-5 weeks.Then it is turned into the middle bin for an-other 4-7 weeks. The material in the middle binis turned into the third and last bin as finishedor nearly finished compost. New material isstarted in the first bin each time it is emptied.

This structure should be made from rot-resistantwood such as cedar, arsenic free treated wood,plastic lumber, or metal posts and wire mesh orhardware cloth. Each bin should be approxi-mately 3-5 feet wide by 3-5 feet high. Remov-able slats in the front and between bins offerscomplete access to the contents for turning.Another design option is making the frontsremovable doors rather than wooden slats.Plastic or hardware cloth can be used to maketops for shedding heavy rain or snow.

Commercial Compost Bins

There are many manufactured compost bins onthe market made of recycled plastic, metal orwood. Check out your local garden center,home supply stores, or the internet. Many localcommunities have annual compost bin salesthrough their recycling program, UW Extensionor other programs.

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“The Pit and Trench”

Pit and trench composting is useful for garden-ers and is frequently done right in their gardenor next to their garden plot. This is an easycompost method requiring no turning.

Dig a pit about 2-4 feet deep. Add yard materi-als, including garden debris (no seeds or dis-eased plants), throughout the summer. At theend of the summer, when the garden is done,cover the pit with 1-3 inches of soil. Next springplant the garden as usual locating the pit in adifferent part of the garden. Before coveringwith soil, food scraps can be added.

The trench is a variation of the pit. Dig a trench18 inches deep. The trench can be located in agarden or next to a garden. Fill the trench withleaves, grass, and garden debris throughout thesummer. At the end of the summer, when thegarden is done, cover the trench with 1-3 inchesof soil. Do not add food scraps until you areready to cover the trench.

Worm Bins

Using worm bins (vermicomposting) is a funand easy way to compost food scraps. Wormbins utilize redworms (not earthworms) to eatfood scraps and turn them into worm castings— a useful garden fertilizer.

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Worm bins are commonly made from simplewood boxes with lids or plastic tubs. Put wormsin the box with shredded, moistened newsprint,corrugated cardboard or shredded office paper.A good rule of thumb for sizing the box is tobuild one square foot of surface for every poundof food waste generated per week and no morethan 12-18 inches high. (Redworms are surfacefeeders). One of the easiest boxes to build iscalled the 1-2-3 box — sides are 1 foot high, thebox is 2 feet deep from front to back, and 3 feetwide from side to side (6 square feet surfacearea), with aeration holes in the bottom and asimple covering of black plastic over the top. Abox this size will handle about 6 pounds of foodscraps per week.

Drill air holes in the bottom of the wooden orplastic box and keep the lid ajar to keep thebox dark, slightly moist, and ventilated. Theworms will not leave the box as long as it iskept relatively moist and there is enough foodavailable. Don’t add more food than wormscan eat or you will have odor problems. Opti-mal temperature for worm bins is between 50˚-75˚ F. Do not let the temperature drop belowthis level or the worms will die! Some peoplekeep their worm bins in the basement. Othersprefer a spot under the kitchen sink.

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Worm bins are usually kept in the house toassure the worms don’t get too cold or hot.

Redworms may be purchased at bait shops,other stores which sell fishing supplies or off theinternet. Be sure to purchase redworms andnot earthworms or other worm varieties. They

consume their ownweight in food each

day! (Other typesof worms eatless.)

Redwormsare onlyabout 2 to4 incheslong whenfull grown,and are notnative toWisconsin.

Making a worm home

Once the worm bin is built, shred newspaper(not the colored sections) or office paper into 11/2 inch-wide-strips until you have about 10pounds of shredded newspaper. Add a smallamount of sand to provide grit for the worm’sgizzard. Add about 4 gallons of water to thepaper to make the worm environment about 75percent moisture. The worms will eat thebedding material and sand as well as your foodscraps.

Feeding your worms

Once you add the redworms to their new home,you can start feeding them your food scraps!They will eat lettuce leaves, apple cores, potatopeels, watermelon rinds, coffee grounds—thelist is long. Avoid dairy and meat products, oils,and oily foods because these foods can causeodors and attract animals and insects. Alsodon’t add citrus and bananas, as they mayhave fruit fly eggs on their skins.

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Add food scraps to the worm bin by digging ahole in the bedding at one corner of the bin andburying the scraps in the bedding. The nextday, bury the scraps at the alternate corner ofthe bin and move down the sides of the binalternating sides every day. Some people simplyadd food scraps to the top of the bedding. Thismethod works, but it can cause odors. If yourbin gets ripe, simply add more bedding mate-rial to the bin. Add some fresh bedding at leastevery two months.

Harvesting your compost

As the worms eat their way through the materi-als in your bin, the contents of the bin darkenand begin to smell moist and earthy. This is thevermicompost (worm compost), your finishedproduct. Vermicompost is full of nutrientsnecessary to promote strong, healthy plantgrowth.

There are a couple of easy ways to harvest yourvermicompost. One way is to carefully movethe finished compost to one side of the bin, andfill the empty side with fresh, moist beddingmaterial. Give the worms 4 or 5 weeks to moveover to the new bedding materials, and thenremove the finished vermicompost.

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Another method is to put a can filled with foodscraps into the finished compost. Punch holes inthe sides and the bottom of the can largeenough for the worms to enter. In 4 or 5 weeksthe can should be filled with worms. The fin-ished compost can be removed from the binwithout the worms. Remember to refill the binwith fresh, moist bedding material.

Using worm compost

Worm compost (vermicompost) is a rich soilenhancer. It contains many nutrients needed togrow strong, healthy plants both in your houseand in your garden. Some of the ways it can beused:

• Mix with peat moss, garden loam, vermicu-lite or sand to make potting soil.

• Sprinkled on your houseplants soil as a topdressing.

• Spread 1 inch thick on the surface of yourgarden or dig it into soil.

• Added by the handful when you transplantvegetables and other plants in your garden.

Commonly-asked Questions

What is compost?

Compost is a soil-like material rich in stabilizedcarbon produced from the breakdown of or-ganic materials (materials that contain car-bon). Most compost is considered a soil condi-tioner (or soil amendment), not a fertilizer,because compost usually doesn't contain veryhigh levels of macro-nutrients (nitrogen, phos-phorus, and potassium - or N, P, K). However,compost may provide low levels of macro andtrace nutrients essential to plant growth. Theprimary benefit of compost is that it increasessoil organic matter. This improves soil waterholding capacity and soil physical properties,

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and allows for greater plant root penetration. Italso increases soil biodiversity (number andtype of microbes and other small creatures inthe soil), which helps plants obtain nutrientsfrom soil, and maintains a balance amongorganisms to help prevent outbreaks of diseasecausing organisms. Aerobic composting (mean-ing composting with air, or oxygen) producesthe best quality compost for agricultural andsilvacultural use (including lawns and gardens).Compost should not contain toxic substances atconcentrations that would negatively impactthe health of human or plants.

What is composting?

Composting is the process that uses microor-ganisms, carbon and nitrogen food, moistureand oxygen to convert plant materials such asgrass clippings, leaves, and other organicmaterials to compost, a more usable organicsoil amendment.

What is mulch?

The term "mulch" is used differently by differentpeople. Perhaps most often, mulch refers tomaterials that are placed on the ground sur-face, around plantings or trees, to preventweeds from emerging and to help retain soilmoisture. Leaves or grass clippings can be usedaround vegetable plants, and wood bark or

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chips can be used around woody stemmed andforest type plants. (Before bringing wood mulchonto your property, learn more to make sure itwon't be a source of disease or insects.) How-ever, the term mulch, or mulching, may alsodescribe any organic material (processed or not)that is mixed into the soil.

What is mulching?

Mulching is using unprocessed yard materialsas a soil cover around plants, shrubs, and treesto enhance moisture retention and suppressweed growth. Yard materials mulch includesgrass clippings, leaves, wood chips, pine needlesand bark. Don’t use grass treated with herbi-cides for mulch. You can also mulch grassclippings right on the lawn with a mower toadd free nitrogen fertilizer.

What are yard materials?

Yard materials are leaves, grass clippings, yardand garden debris, and brush no greater than 6inches in diameter. Included as yard materialsare raw garden vegetable plants, tree seeds,pine needles, weeds, flowering plants, seeds,small woody materials, and pine cones.

When should I start my composting?

Start your pile any time in spring, summer orfall. Be sure to save several bags of leaves in fallso you have carbon to use in July when youhave lots of grass and garden debris.

Do compost piles freeze in winter?

Home compost piles usually freeze duringWisconsin winters, but will restart on their ownwhen they thaw in spring. Approximately 64cubic feet of materials is needed to preventfreezing, and this amount of material mayremain somewhat active, meaning decomposi-tion may continue to occur, but at a greatlyreduced rate. A much larger amount of mate-

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rial, probably too much for a home composterto manage, or an insulated bin, would beneeded to maintain a hot composting pilethrough winter.

How does composting fight plantdiseases?

Compost can fight some plant diseases eitherthrough competition of micro-organisms orfrom chemicals produced in the compost.

Why are pet wastes not acceptable to usein compost?

Pet wastes from cats, dogs, meat eating animalsand birds contain pathogens (disease organ-isms) which can be transmitted to humans.These pathogens are destroyed by high heat,but home composting may not be sufficientlymixed, and all materials may not reach thenecessary temperatures. Manure from planteating animals can be composted safely butshould be done only in a hot pile.

Can I add pine needles to my compost?

Pine needles are high in acid and resin, whichcan make them difficult to compost. Thesemake a good mulch for acid loving plants suchas lilies of the valley, blueberries, raspberries,blackberries, roses and conifers. The best use ofpine needles is to leave them under the pine

tree where they fall. Pineneedles condition the soil

and protect theshallow rootsystem of theirparent tree.

No more than 10 percent of a mixed yardmaterial pile should be pine needles. Somegardeners compost pine needles with leaves oranother carbon source separately for their acidloving plants.

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Can I add oak leaves to my compost?

Oak leaves compost well, but a little slower.Although they are acidic, the compost process isa great neutralizer. Once oak leaves arecomposted, the finished compost will have a pHclose to neutral. To help oak leaves break downfaster in a compost pile, consider using yourlawn mower to chop them into finer piecesbefore adding them to your pile. This willexpose more surface area to the microorgan-isms and speed up the compost process.

Can I use agriculture lime on my compostpile?

Lime is not recommended as it can harm micro-organisms, cause ammonia odors and slow thecomposting process.

Can I add toxic weeds or plants to mycompost pile?

Many of the native plants and weeds in Wis-consin that produce toxins(black walnut orbutternut leaves,nightshade, monks-hood, etc.) can beadded to your com-post pile. Compostthese in smallamounts only. How-ever, black walnut orbutternut leaves should not be used as mulch(without prior composting). To identify aspecific plant and see if it is toxic, check withthe local library or the local county extensionagent before adding it to your compost pile orusing it as mulch.

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Where should I put my Compost Pile?

Here are some guidelines on where to locateyour compost pile:

• Within reach of water with a garden hose.

• In a convenient area near garden or house.

• Protected from direct winds.

• In a spot with good drainage.

• Three feet away from buildings to eliminateheat and moisture damage from thecomposting process.

• Away from neighbors' windows.

What if I don’t have enough materials tostart a compost pile?

Sometimes you will end up with too much ofone type of material, and not enough of an-other. Here are some suggestions for balancingout your compost pile:

Not Enough Grass: You will need to add anothernitrogen source to your compost. Add a 2-inchlayer of livestock manure, or 1 cup of 10-10-10fertilizer per 25 square feet of top surface areawith a 3 foot depth.

Not Enough Leaves: Grass is a high source ofnitrogen and is small in size and easily com-pacts. Grass must be mixed with some bulkingmaterial such as wood, leaves, plant stalks orchips to provide a carbon source and allow airto circulate through the pile. Composting grasswithout a bulking material can create a strongammonia smell.

Does a composting require a license orapproval?

Usually compost piles are fine as long as theyare maintained in a nuisance free manner.However, check with your local municipality tosee if there are any backyard composting rules.Your local community may have additionalrequirements or limitations on backyardcomposting of food scraps. Composting of only

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yard materials, vegetable wastes and manure, ifless than 50 cubic yards in size at one time,does not require an approval or license from theDNR.

Will the compost pile smell bad?

It shouldn’t. A properly-tended pile won’t createunpleasant odors. Turning the pile to addoxygen or adding a bulking carbon sourceshould end an odor problem quickly. Finishedcompost has a pleasant earthy, greenhousesmell.

Will the compost pile attract animals?

You might see animals around your compostpile if you are composting food scraps improp-erly. Food scraps should be buried 8- 10 inchesinto the center of an enclosed compost pile. DONOT throw food scraps on top of your compostpile at any time! Animals will come around ifyou supply them with an easy food source.

What happens to pesticides when theyare composted?

Pesticides include herbicides (weed killers),fungicides (fungus killers) and insecticides(insect killers). Most pesticides which are cur-rently available to homeowners are degradableorganophosphates. The active ingredients inmost pesticides usually break down in 6-8weeks.

Grass clippings or weeds treated with pesti-cides can be safely mixed into a compost pileor mulched back onto your lawn.

WARNING: Uncomposted grass and weedstreated with pesticides should not be used as agarden mulch. Pesticide treated yard materialsdon’t know the difference between plants andinsects you want to keep and weeds and bugsyou want to kill.

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References

This brochure is designed to answer some of thecommon questions people have aboutcomposting and yard management. If you areinterested in more information on the topicsdiscussed in this brochure, check with your locallibrary for the following publications:

www.uwex.edu/ces/shwec. UW-ExtensionSHWEC – Composting information, bin plansand resources and vermicomposting

Compost Indoors!: Worms do the Work.Applehof, Mary. Organic Gardening (pp. 58-63), January, 1992.

Worms Eat My Garbage, 2nd edition.Applehof, Mary.,Flowerfield Press, l997.

Backyard Composting Brown, Deborah &Carl Rosen. Minnesota Extension Service,University of Minnesota, Agriculture, 1990.

Let It Rot!: The Gardeners Guide toComposting. Stu Campbell, Storoey Books,1990.

The Rodale Book of Composting: EasyMethods for Every Gardener, Debra Marin,et. al. 1992.

Backyard Composting: Your CompleteGuide To Recycling Yard Clippings. Har-monious Technologies. Ojai, CA, 1992.

UW Extension

A3383 - Mulches for Home Harrison, H.C

A3384 - Specialized Gardening Tech-niques Harrison, H.C, 1991

A1989 - The Vegetable Garden. Harrison,H.C., 1992

GP6/05

PRINTED ONRECYCLEDPAPER

Other Resources:

For more information on composting or DNRyard waste regulations, contact your municipalrecycling staff, a County Extension Agent, or aDNR recycling specialist.

Other yard waste management brochuresavailable from DNR are:

PUB-WA-072, Home Composting: Reap A Heap ofBenefits

PUB-WA-073 2004, Yard Care: Do Your Share!

Wisconsin Department of Natural ResourcesPO Box 7921Madison, WI 53707608/266-2111

Illustrations: Joal Morris

The Wisconsin Department of Natural Resources providesequal opportunity in its employment, programs, servicesand functions under an Affirmative Action Plan. If youhave any questions, please write to Equal OpportunityOffice, Department of the Interior, Washington, D.C.20240.

This publication is available in alternate format (largeprint, Braille, audio tape, etc.) upon request. Call 608-266-2111 for more information.