Composting and Worm Farming - Northland Regional Council

Composting andWorm FarmingNature’s Recycling SystemCaring for Northlandand its environment

Why compost?Every year Kiwis throw away more than three million tonnes of rubbish, of whichmore than 45% is food waste!Every 6kg of unsorted rubbish sent to landfill emits nearly 5kg of carbon dioxide –a greenhouse gas - into the atmosphere. Yet most of what we throw away could besorted and disposed of in a far more eco-friendly way.What is compost?Nature’s recycling systemYour household produces an enormous amount of waste each year that could becomposted. Having a compost or worm bin in your backyard is a great way to reduceyour waste and help protect the environment.Home composting has many benefitsCompost is a natural fertiliser and soil conditioner. It improves soil fertility andtexture, and retains moisture and nutrients.It is cheap and is easy to make.The amount of water pollution, gas release and odour from landfills is decreased.Air pollution is reduced from burning garden waste.Your garden will require fewer garden chemicals because compost-rich soil growshealthier, more productive plants which often have more resistance to pests.Compost or mulch also reduces the amount of water used because soil does not dryout as fast.Composting is easy and you can choose a system to suit your lifestyle. You maycompost at home with a compost bin or worm farm, get a garden bag company tocollect your garden waste or deliver your garden waste to a composting drop-offpoint at your local refuse transfer station.AcknowledgementsThe Northland Regional Council acknowledgesthe Auckland Regional Council and ChristchurchCity Council Waste Management Unit for theinformation contained in this brochure.ISBN 0-909006-24-5

CompostGetting startedYou can either buy a compost bin or make awooden box for the compost. If you arebuilding one, remember to leave spacebetween the slats of wood for air circulation.A 1 x 1 metre compost bin is a good size.All compost bins should be bottomless andplaced on the bare ground in a sunny spot.They work best in a warm, moist location.Begin with a bottom layer of coarse plantmaterial like twigs, followed by alternatelayers of garden waste and food scraps witha thin layer of soil.What to include in your binYou will need a variety of materials whichare found naturally in your garden or comefrom the kitchen. They are called “Greens”and “Browns.”Greens - are nitrogen-rich wastes likekitchen food scraps, fruit peels, coffeegrounds and tea bags, grass and plantclippings, hair, animal fur, blood andbone, seaweed, fish bones and choppedweeds (except for Onion Weed,Wandering Jew, Wild Ginger andOxalis).Browns - are high in carbon and otherelements. These may be dried leaves,sawdust, wood shavings, hay, peat,vacuum cleaner dust, shredded paper,and newspaper, eggshells and crushedseashells, coal ash, wood ash (untreated),chicken manure, blood and bone.What to leave out of your binMANURE • FISHBONES • SEAWEEDEGGSHELLS • SEASHELLSGRASS CLIPPINGS • CHOPPED WEEDSDRIED LEAVES • PEAT • HAYSOIL (or COMPOST ACTIVATOR)KITCHEN FOOD SCRAPSFIRST LAYERCOARSELY CHOPPED PLANT MATERIALAIRAIRExample of compost layers.Courtesy of Auckland Regional Council.Meat, grease, fat, dairy products, large bones, food packaging, plastics, wood products,pest plants (see www.nrc.govt.nz for more information), and underground stems, forexample kikuyu grass stems. Cat and dog faeces are not recommended in largeamounts. They may create an odour problem and there are very little nutrients in them.

Speeding up the processThe smaller the pieces of food and garden waste, the faster it will decompose.If you don’t have a lid on your system, cover the compost in heavy rain.Keep composting material moist – don’t let it dry out.If at first it doesn’t heat up, add more ‘green’ material, and manure or blood andbone.Composting slows down in winter, but you can continue to add organic materials.It’s fine if your heap freezes, but if you want your heap to continue decomposingthroughout the winter, add an insulating layer of plastic over the heap.When is it ready?Ideally the finished product should look like potting mix. However, it will not matter ifit isn’t perfect. As long as most of the material is broken down (egg shells will notcompletely disappear) and you have material with a soil like structure, your compost isready to add to your garden.Caring for your compostYour compost bin or heap is not a dump!The main ingredients for good compost area good mix of materials, including greenslike lawn clippings, to produce heat,moisture and air.Chop or shred garden waste up intosmaller pieces and mix with otheringredients in the bin.Turn your heap or the contents of thebin. After it heats up and cools down,turn to mix the ingredients. The heatdestroys the weeds and seeds. You mayturn it into another un-layered heap orbin if you have one or just stir up thecontents of your existing bin.Keep moist, but don’t drown yourcompost.Cover your heap or bin in heavy rain.If it becomes too wet, turn it and add‘brown material’.Turn your heap if it develops a badodour.As part of being a NorthlandEnviroschool, Onerahi Primary Schoolestablished a composting scheme.

Worm farmingWhy worms?Simple, natural and fun!The worms eat your kitchen food scrapsand process them into castings. Thisreduces the rubbish you put out at yourgate and makes an excellent soilconditioner.Worm tea is the liquid waste theworms produce. This is also aneffective fertiliser.It’s a great system for people withlimited space.It’s an easy and fun way for peopleof all ages to recycle kitchen waste.What is worm farming?Worm farming is also known asvermicomposting, vermiculture, wormfarms, worm bins or a wormery. It is aself-contained composting system thatdoesn’t generate heat, and retains mostnutrients for reuse. This system is notable to take garden waste and sometypes of food waste, but they arecompact and moveable, which makesthem great for people who have limitedspace. Properly maintained, it is anodourless system and worm castings(manure) make excellent compost.The worms, usually Tiger Worms, areexactly the same as those in a compostbin or heap, but are contained in asmaller transportable bin that can beindoors, outdoors, on a porch orverandah.Tiger Worms are not the same as theearthworms found in garden soil. TigerWorms will not survive in the gardenand need the dark and moistness of aworm bin or compost bin to live.Worms live to eat!Getting startedAnyone can start a worm bin. All youneed is a suitable container, beddingmaterial, and of course, worms.Where to buy your wormsYou can buy worm bins from TheWarehouse (all stores), Payless Plastics,Mitre 10 stores and some hardware retailoutlets. Check online at sites such asTrade Me.Worms are available from:CBEC Eco Solutions Whangarei 09 438 8710or e-mail ecosolutions@cbec.co.nzWorms are also available through certainstores and via mail order. Try an internetsearch, Trade Me or the Yellow Pages.

A home for your wormsMaking a worm binYou can recycle or make a suitablecontainer from wood, plastic or metal.Old tyres or baths make great worm binstoo. The container should ideally be 20-40cm deep with a relatively large surfacearea (about 40 x 40-60cm) becauseworms like to work near the surface.Worms need air to live, so put a fewholes in the bottom of the container foraeration and drainage. If the contentsget too wet, then drill some more holes.Bins should be raised up on bricks orblocks to aid air circulation anddrainage.You can place a tray under the bin tocapture excess liquid. This makes anexcellent plant fertiliser. Use diluted at arate of one part liquid to 10 parts water.Setting up your wormeryOld carpet and canvas are ideal forcovering a ground-based worm farm.Place moist bedding (shredded paperor similar) in the worm bin, plus oneor two handfuls of coarse sand ortopsoil.Add tiger worms (1000 or so). Youcan buy these locally or via mailorder. Alternatively, you can sourcethem yourself as worms livewherever a good supply of organicmaterial is available. Check yourfriends’ compost bins for worms or afarmer with a mature manure heapand collect the worms. Kids willlove this!Bury kitchen scraps just below thesurface of the bedding.Cover with sacking or a loose fittinglid that will keep the material fromdrying out and provide a darkenvironment for the worms.Additional fresh bedding should beadded at least every two months.Harvesting your compostHarvest the compost (worm castings)after three to four months and feed toyour plants.The easiest method is to use a hand forkto remove the top 150mm layer and setit aside for starting the next bin. Theremaining contents can then be removedfor either immediate use or stored untilrequired. Put the top layer back into thebin with some fresh bedding to start theprocess again.Alternatively, tip the entire contents ofthe bin onto a tarpaulin or plastic sheet.Spread the compost to form a layerapproximately 100mm thick. The wormsdislike light and burrow deeper. Over aperiod of about an hour, you can removethe compost in layers as they movedeeper and you will be left with a massof worms which can be added back intothe worm bin with new bedding.You may prefer to simply move thefinished compost over to one side of thebin, place fresh bedding into the spacecreated and add food waste to the newbedding only. The worms will graduallymove over and the compost can beremoved.Top up the bin with fresh bedding toreplace the compost removed. Theworms require bedding in which to liveand lay their eggs.

From this…… to thisSuitable bedding includes newspapertorn into 25cm wide strips (avoidcoloured print), cardboard, peat, straw,aged manure or compost. Sawdust isnot recommended as it contains resinand similarly, chicken manure should beavoided as it is too acidic.It’s as simple as that.What to feed your wormsFeed worms left-over food scraps,vegetables and non-citrus fruitpeelings, tea and coffee bags, coffeegrounds and eggshells.Meat, fish and dairy products maybe fed in moderation. Make sure youbury them in the bedding (not toodeeply) to avoid odours and flies. Ifodours are a problem, then leavethese products out.Don’t feed your worms onions, oil,fats or oily foods, citrus peelings oracidic fruit, peppers, or spicy foods.Garden waste is generally notsuitable for these worms. Materialssuch as grass clippings heat upquickly, which can kill the worms.Garden waste is best dealt with byconventional composting.Top tipsPut your worm bin in a sheltered, shadyarea, away from wind and sun.To prevent odours, slimy conditions andattracting flies, add food regularly ratherthan in large quantities. Food in excesswill sour and rot before the worms candeal with it.Odours generally occur because thesystem has been overfed, allowed tobecome too moist or the bedding hasbecome packed, limiting airflow. It isimportant to fix this, otherwise theconditions may kill the worms.Chopping or mincing up food scrapshelps speed up the process.Add crushed eggshells or a lightsprinkling of dolomite or garden limeonce a month to ensure a goodenvironment for the worms, who don’tlike acidic conditionsWorms need to be kept moist, but notsoggy. If they dry out too much theywill die; but if things are too wet theywill drown.Be aware, that as worm farming doesn’tgenerate heat, any seeds included withthe food (eg pumpkin or tomato) maystill germinate!Using the worm compostFinished worm compost is rich innutrients. It can be used for pottedplants or in the garden. Use in smallamounts (a handful mixed into the soilwhen transplanting plants gives plants agood start).Compost used as part of a potting mixor as a topdressing around potted plantsshould not contain worms.

Northland Regional Council OfficesOpua OfficeUnit 10, Opua Marine Park, Opua 0200.Telephone: 09 402 7516 Facsimile: 09 402 7510Kaitaia Office192 Commerce Street, Kaitaia 0410.Telephone: 09 408 6600 Facsimile: 09 408 6601Dargaville Office61B Victoria Street, Dargaville 0310.Telephone: 09 439 3300 Facsimile: 09 439 3301Main Office36 Water St, Whangarei.Private Bag 9021, Whangarei 0140.Telephone: 09 438 4639 Facsimile: 09 438 0012Email: mailroom@nrc.govt.nzFreephone: 0800 002 00424/7 Environmental Hotline: 0800 504 639Website: www.nrc.govt.nzCaring for Northland and its environmentPrinted on 100% recycled, chlorine and acid free paper with vegetable-based printing inks.Calders Design & Print Co. August 2007.