Make your own compost
Making your own compost is the ultimate in recycling—it takes kitchen scraps and yard waste and makes it into the best, cheapest, and most ecologically-friendly fertilizer out there.
How to make compost
Composting is the process of converting organic material into rich, organic humus—the gardener's "black gold." The material is broken down by microorganisms such as bacteria and larger organisms such as earthworms. Composting happens in nature without human intervention—all organic matter decomposes sooner or later. The gardener’s goal is simply to make it happen sooner.
Basic steps for making compost
- Pick a location for your compost.
- Choose a container to collect kitchen scraps.
- Decide which type of composter you want to use.
Get a container to collect kitchen scraps
Your container can be a ceramic or stainless steel crock that sits on the kitchen counter, a recycled plastic quart-size yogurt container that sits under the kitchen sink, or a lidded garbage pail.
Create a compost pile
The easiest way to make compost if you have a large yard is to pick an out-of-the-way spot and start a compost pile. Empty yard waste, kitchen scraps, and leaves into the pile. (See the list below for what materials should be composted.) Over time the pile turns into compost. Dig compost from the bottom of the pile once it's done. The advantages: it's easy. The disadvantages: temperatures are most likely not high enough to kill diseases or weed seeds, so don't add weeds after they've gone to flower, and don't add any diseased plant material. This is a good solution if you have a fairly large property and not a lot of time.
Use a compost bin
If you don't have a large yard, enclose the compost in a bin, that you can make or buy. One easy way to make a home-made bin: buy 48 inch hardware cloth with 1/2 to 1-inch mesh and form it into a circle 3 feet in diameter. A square bin can be made from recycled wooden pallets. The bin should be at least one cubic yard (3 feet high by 3 feet wide by 3 feet long) so that the internal temperature rises enough for decomposition to take place. Home-made compost bins can be made of untreated wood, concrete blocks, bales of straw, or other materials. Bins should be open on the bottom and set on the soil or grass, and should have slats or holes to allow air to circulate.
Hot heap or cool heap?
To build a "hot heap," you need a compost pile or bin that is at least 1 cubic yard to generate enough heat. The traditional way to make a "hot" compost heap is to make the pile in one session, by adding alternating layers of "green" and "brown" materials to the bin. (See below.) Collect material of each type in separate bins until you have enough to create the heap. Add soil every few layers and keep the pile moist but not wet. Cover, and after two weeks mix it with a pitchfork, digging material from the outside to the hotter center of the heap. This aerates the pile, helping the decomposing microbes to work. Ideally, you should have two or more bins to "turn" the material from one bin to the next. Learning how to make hot compost takes practice. If you turn the heap once a month, you'll get compost in three to four months. A hot heap reaches temperatures of 140°F - 160°F. The advantages of this method are that the heap is hot enough to kill weed seeds and pathogens and it produces a lot of compost quickly. The disadvantages are that it takes a lot of time, space, and work.
The hot-heap method may be impractical for many home gardeners who don't have the time, space, or materials to make compost this way. An easier alternative is to just add kitchen scraps and yard waste to the compost bin as you have it. Cut materials into smaller pieces, if possible, and they'll decompose faster. Add a little lime or wood ash to "sweeten" the pile (make it more alkaline), and add some garden soil to activate decomposition. Turn (mix) the pile to speed up the process. This is a "cold heap"— the internal temperature of the pile won't get hot enough to kill weed seeds and pathogens. The advantages of the cold-heap method are that it takes less time and work. The disadvantages are that the pile isn't hot enough to destroy weed seeds or pathogens, and that it takes longer to produce compost than with a hot heap.
Use a compost tumbler
Tumblers produce compost more quickly and provide good heat. They're also self-contained, neat, and more attractive than an open pile or bin, and can be located anywhere. Disadvantages are that while they're easier to mix than fork-turning materials in an open bin, they need to be turned either by flipping the container end-over-end on its stand (with a barrel-type model) or turning the rotating drum with a crank (with an drum-type model), and a full container can be heavy.
Solutions for city dwellers
If you're an apartment dweller, try worm composting. A worm bin composting system can be set up indoors or on a balcony. Another solution for city dwellers is an electric composter.
What materials can be composted?
There are two categories of compostable materials:
- Greens contain a lot of nitrogen. Think "fresh."
- Browns are high in carbon. Think "dried."
Green materials that can be added to compost:
- raw fruit and vegetable peels, rinds, or scraps
- fruits and vegetables that are past their prime
- coffee grounds - add a little lime or wood ash, since they're acidic
- tea grounds or tea bags
- egg shells - crush them, since they decompose slowly
- stalks, stems, and leaves from spent garden plants
- lawn clippings - best left on the lawn as mulch, but they can be added to compost if they're from lawns grown without chemicals
- animal manure - from organically-raised rabbits, chickens, pigs, sheep, horses, and cattle
Brown materials that can be added to compost:
- fall leaves - shred leaves by running over them with a lawn mower, otherwise they mat down and decompost too slowly
- nut shells
- crumpled paper (not chemically treated)
- old wool or cotton clothing, torn into small strips
- paper bags, cardboard, and egg cartons - torn up into small pieces
- cornstalks - chop up with a pruner so they'll break down more quickly
- salt marsh hay
Sawdust, wood chips, and pine needles may be added to the compost heap, but they're better used as mulch. Add wood ash sparingly: it increases alkalinity, but it's easy to add too much. Add no more than 2 gallons of wood ash to a 3-cubic-yard compost pile.
What materials shouldn't be composted?
- cooked food - it may attract animals or vermin
- dairy products
- meat or bones
- invasive plants - you could end up spreading them all over the garden
- woody plant material - it takes too long to decompose unless you cut it up or shred it first
- cat or dog feces - compost your pet's waste separately, as it may contain pathogens
- used cat litter
- coal ash or charcoal
The following shouldn't be added unless you're absolutely sure your compost reaches a high enough temperature to qualify as a "hot pile." If you're not sure, best to avoid them:
- any plant material that's diseased or infested with pests
- weeds after they've gone to seed - you risk planting weed seeds when you add the compost to the garden if your compost isn't hot enough
Some companies offer compost activators: they're basically high-nitrogen products to get the compost started. You can save money by just adding a shovel of soil. Also great starters are any alfalfa products—baled alfalfa or any alfalfa meal product. Rabbit food, horse feed, even some cat litters are almost pure alfalfa meal.
How do you know when the compost is ready?
Compost is ready when it looks like dark brown, crumbly soil.
Find it! Composting tools
Even the city-bound can use this electric composter. The company claims it can be used in the kitchen, has carbon filters to eliminate odor, and costs about 50 cents per month to operate, depending on local electric rates.
Put a stylish ceramic or stainless steel compost crock on your kitchen counter, empty it into a Tumbler Composter outside the kitchen door, and you'll have compost in less then a month.
The Scrap Eater is an attractive garden planter, as well as an efficient composter. The composter uses solar technology and is made from three quarters of a solid oak Bordeaux wine barrel with a clear acrylic plastic dome.
Making your own compost helps you go green because…
- It keeps kitchen and garden waste out of overburdened landfills.
- It saves on trash bags and lawn bags often used to collect these materials.
- It saves the time, money, and transportation costs it takes to collect kitchen and garden waste.
In the US, people generated 251 million tons of municipal solid waste (MSW) in 2006—or 4.6 pounds per person every day—while municipal composting recovered 21 million tons by receiving yard trimmings, food scraps, and other organic materials. Municipal solid waste is comprised primarily of organic materials. Paper and paperboard products made up the largest component of MSW (85 million tons, or 34 percent), with yard trimmings contributing the second-largest component (32.4 million tons, or almost 12.9 percent). Food scraps comprised 31.3 million tons of the total waste, or 12.4 percent. While 62 percent of yard trimmings were municipally composted, only 2.2 percent of food wastes were. These figures don't include backyard composting.
The US Environmental Protection Agency (EPA) strongly recommends that people use backyard composting of food scraps and yard trimmings to keep these materials out of landfills. By making your own compost, you can do your part to recycle these organic wastes, especially if you live in an area that doesn't have municipal composting. Since 68 percent of municipal organic waste is organic (yard waste, food scraps, paper, and wood), as the American Composting Council says: "If you are not composting, you're not recycling."
Adding dog and cat waste to the backyard compost pile - especially for use in the vegetable garden - is often debated. The problem is that meat-eating animals can carry pathogens (disease-causing organisms). In particular, cats can carry a disease called toxoplasmosis, and dogs can carry roundworms. If a compost pile maintains an internal temperature of 131°F for at least 15 days, and the pile is turned at least five times, these pathogens will be killed. Most gardeners, however, don’t monitor the temperature of their compost pile. Therefore, while materials such as meat, feces from meat-eating animals, fats, and paper diapers can legally be composted in commercial composting facilities that meet EPA standards for pathogen destruction, these materials should not be used in backyard compost operations.
Related health issues
Cat feces should not be added to the home compost pile, since cats may transmit a serious disease called toxoplasmosis. Cats may get the parasite from coming into contact with raw meat or eating mice. People can even catch this disease from handling used cat litter. Contracting toxoplasmosis is especially dangerous for pregnant women and people with AIDS, and can be fatal for children under 2 years old. Toxoplasma organisms can survive in the soil for years and will not be destroyed by the typcial backyard composting process.
Dog and cat feces may also contain parasitic roundworms, which can lead to an infection called toxocariasis. This infection can be transmitted to humans and cause an eye disease that may lead to blindness.
- compost: A mixture of decayed organic matter that is used for fertilizing and conditioning soil
- humus: Organic matter that is converted by microorganisms into a state that can’t be broken down further
- Home & Garden Television - Indoor Composting: No Gnats, No Smell Choose an easy, convenient indoor compost option.
- Videojug - How to Hot Compost Watch a video on how to make hot compost.
- Compost Guide - A Complete Guide to Composting Read about how to compost, what to compost, and troubleshooting tips.
- Brooklyn Botanic Garden - Recycled Products:Turning Trash into Garden Tools" Learn how to reduce waste, compost, and use recycled materials in your garden and yard.
- The New York City Compost Project A fantastic resource funded by the New York City Department of Sanitation that's geared towards urbanites interested in composting.
- Compost Guide - A Complete Guide to Composting
- Hart, Rhonda (1995) Dirt Cheap Gardening. Pownal, Vermont: Storey Communications, Inc.
- US Environmental Protection Agency - Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2006
- US Environmental Protection Agency - Municipal Solid Waste in the United State: Facts and Figures
- Brooklyn Botanic Garden - Recycled Products: Turning Trash into Garden Tools
- Earth 911 - Backyard Composting: Ants, Cats, Dogs, and other Varmints
- US Centers for Disease Control - Toxocariasis Fact Sheet