Nearly half of what we throw in our trash cans could be composted, according to Daniela Ochoa Gonzalez, a planner with Austin’s Resource Recovery department. Instead of going to the landfill, food scraps, napkins, paper, pizza boxes, egg shells, coffee grounds, tea bags and more can be turned into rich, healthy soil for your yard or garden. The city’s Zero Waste plan, which aims to reduce our waste by 90 percent, seeks to encourage more individuals and businesses to compost.

Composting takes little time or effort, and only a small initial investment in supplies. All you really need is a place to keep materials while they compost. Options run from the primitive (a pile on the ground) to homemade open bins to commercial containers. Directions for building your own container can be found online from the University of Arkansas and University of Florida. Commercial bins can be purchased at local home improvement stores, or ordered online from local gardening supply company Exaco. You can also buy Exaco bins at the Barton Creek Farmer’s Market on Saturdays and at Northwest Hardware and Zinger Hardware.

It’s handy to have something in your kitchen that you can put scraps and other compostable household materials in until you’re ready to take them out to your pile. This can simply be a jar or bucket. If you attend one of the city’s free composting workshops, you’ll get a nifty container with a lid to take home.

The city of Austin also rebates 75 percent on purchases of composting supplies (up to $75), provided you attend a workshop and downsize to a 32-gallon trash cart.

Balance is important to successful composting. Ochoa says research has shown that the ideal ratio is one “green” unit and three “brown” units. Green items, which are nitrogen-rich, include food scraps such as onion skins, apple cores, banana peels, spoiled vegetables and fruits, crushed egg shells, bread, pasta, cereal, cookies, seeds, nuts, tea bags and coffee grounds and filters.

Brown items contribute carbon to the mix. These include leaves, dead flowers and plants, toothpicks, sawdust, paper bags and napkins, newspaper, shredded paper, cardboard, lint, cotton balls and wool. Pizza boxes, which can’t be recycled, can be torn up and composted.

Things that don’t belong in your compost bin include meat, poultry, fish and bones; milk, cheese and other dairy products; greasy, oily food; non-biodegradable materials such as plastic and metal; ashes; waxed or glossy paper; synthetic fibers; and weeds or invasive plants. Pet poop is another compost no-no. A good rule of thumb to remember is “If it grows, it goes” into the pile.

The right amount of moisture will speed up the composting process. Ochoa suggests using a soaker hose, or poking holes in the bottom of a plastic milk jug, then filling it with water and setting it on top of the compost (this works well if you’ll be out of town). To get the right balance in her compost pile, Ochoa puts in the stuff from the container in her kitchen, then uses that container to add three times that amount of leaves from a pile in her yard, then she rinses the container and pours that water over the compost.

If liquid leaks out the bottom of your bin, it is probably too wet. Add more dry items such as leaves or paper, and mix the compost. If your pile isn’t decomposing (it doesn’t get smaller, and scraps and other items are still recognizable), then you may not have enough moisture. Add some water and moist items, like banana peels.

If your compost is breaking down slowly, you may also be putting in items that are too big. The micro-organisms that break down your materials can work faster on smaller pieces. Cut or break up large items such as watermelon and grapefruit rinds and cardboard or pizza boxes.

A compost pile that smells bad probably needs more brown items, and more air. Add leaves or paper and mix the pile.

Turn your pile every other week and you will get compost in four to six months, Ochoa says. Turn it every week and you’ll have compost in about three months. Don’t turn it everyday, or you will disturb the micro-organisms and keep them from doing their job. If you’re into low maintenance, you don’t have to turn your pile at all. You’ll still get compost, but it will likely take about a year.

When you turn your compost, you can remove the bottom layer if it’s ready. Compost is “ready” when it looks, smells and feels like healthy soil or earth. If you want to be sure, use the jar test. Put a handful in a jar, add enough water to make it soggy, and seal the jar. In about a week, open the jar carefully.

If it smells like nice, wet earth, it’s ready. Finished compost is dark brown or black, crumbly, with an earthy smell.