What is composting? Composting is the process of recycling organic matter into valuable fertilizer that can be used to enrich soil and plants.
Composting is simple to do at home in your backyard. You can compost even if you live in an apartment since many localities now include a composting center as part of their community waste management. Some states, like Vermont, even require residents to compost their food waste.
What Can You Compost?
While much of the organic waste we produce can be recycled into compost, not everything is compostable.
Items you can compost:
- Fruits and vegetables, their peels and scraps
- Coffee grounds, coffee filters, and tea bags/tea leaves
- Leaves, grass clippings, flowers
- Nutshells (except walnuts*)
- Paper, cardboard, shredded paper
- Napkins, paper towels, unused toilet paper
- Hair and fur
- Wood chips and sawdust
Some items should not be composted because they can attract rodents or pests, spread disease or contain harmful compounds that are toxic to plants.
- Any kind of pet waste or litter - may contain harmful bacteria or parasites
- Dairy products, meat, fish, or poultry - produce odor and can attract pests
- Plastic - does not decompose naturally
- Leaves, twigs, or shells from walnut trees - *release a compound toxic to plants
- Coal ash or charcoal - also releases toxic compounds
- Fat, oil, or grease - produces odor and attracts pests
- Diseased plants or plants infected with insects - may spread disease
Where Should You Compost?
While there are several composting methods, we’ll be discussing a simple compost pile. This method also works for an open compost bin. A simple pile in a corner of your yard is more than adequate for generating compost. You do not need a fancy compost bin or barrel; however, they may help keep things neater and help you decompose your compost.
You will want to choose a dry and shady spot to better control your pile's moisture level. A 3-foot cube is the recommended size of a compost pile, whether it be in a bin or simply a pile.
How to Compost
There are 2 main methods of backyard composting: cold composting and hot composting. Cold composting consists of simply creating your compost pile in any fashion you choose and leaving it alone for Mother Nature to do her magic. It can take one to two years to generate compost this way.
Most home composters use a hot composting method which takes advantage of microorganisms, heat, and some elbow grease to speed the composting process.
Composting requires three basic ingredients:
- Brown material - this includes things like dead leaves, branches, twigs, paper
- Green material - this includes things like grass clippings, vegetable scraps, fruit scraps, and coffee grounds
- Water to aid in breaking down organic matter
You’ll want to start with a 4-8 inch layer of brown material to provide drainage and aeration and then alternate green and brown material as you go. Your compost pile should have equal amounts of brown and green material in alternating layers and enough water to keep the pile moist like a wrung-out sponge. Brown material provides carbon, green material provides nitrogen, and the water helps it all break down.
Hot composting happens when the balance of browns, greens, air, and water creates ideal conditions for aerobic organisms to thrive. Your compost pile will start generating its heat with an optimal temperature of 130 to 140 degrees Fahrenheit. At this point, you’ll want to keep the reaction going by turning your compost pile about once a week in the warm Summer months and about once every three to four weeks in Winter.
When Is Compost Ready to Use?
Compost needs to stabilize and mature in order to be used. Immature compost can damage your plants and attract pests. At some point, you will need to stop adding material to your compost pile and let it “rest” to allow it to mature. Some people have three different compost piles so they can stage their compost appropriately.
There are several ways to determine if your compost is ready to use. First of all, it should look like crumbly dark topsoil. There should be a pleasant earthy smell and no ammonia smell. You should not be able to recognize any of the original organic material except for some larger sticks or wood chips that you will want to screen out before using. Your compost pile should have shrunk to one-third to one-half the original size and the temperature should be cool, within 10 degrees Fahrenheit of the temperature outside.
One way to test if your compost is ready is to put a handful into a sealed container and let it sit for about 3 days. When you open the container, if it smells sour, there are still microorganisms at work and it needs more time to cure. If it smells pleasant and earthy, it has cured entirely and can be used.
How to Use Compost
Your mature compost can be used as a soil amendment, as mulch, to create a potting mix, or even to make compost tea, a liquid fertilizer you can spray on your plants to help fight disease.
- For annuals, ground cover, shrubs, and trees - add compost to the top 3 to 5 inches of topsoil to restore nutrients
- For vegetables - add several inches of compost to your garden beds in the fall and till it in the spring
- For flowers and potted plants - mix 1 to 2 inches of compost into your soil a couple of times of year
Spread 1-3 inches of compost on the surface of your soil and rake to distribute evenly. It will protect from erosion, retain moisture and add nutrients as it decomposes.
Create your potting mix with 1/3 screened and cured compost, 1/3 expanded coco peat (coconut fiber), 1/6 perlite, 1/6 vermiculite.
Steep a small amount of compost in water for 24 to 48 hours and then strain the mixture and spray on your plants to supply nutrients.
The Benefits of Compost
Composting reduces the waste stream since food waste and garden scraps can make up to 28 percent of what we throw away. The decomposition of organic waste in landfills is the third largest source of human-generated methane emissions in the United States! Most of all, compost improves soil, lessens erosion, and conserves water since it allows the soil to retain moisture and nutrients more efficiently.
There is no exact science to composting, so don’t worry about getting things wrong. Your compost will decompose eventually, no matter what. While you’re waiting, don’t be afraid to experiment with different ratios of browns, greens, and water or to vary how often you turn your pile. Different types of scraps decompose at different rates, and various weather conditions can have a big effect on things, too. Just like with all gardening techniques, the more you compost, the more you’ll learn - and what works for someone else might not for you. You’ve got this! The end result will be worth the time and effort - for both your garden and the environment.