Composting 101
How to Turn Yard Waste and Table Scraps into Garden Gold!

Science–All Grade Levels

Most gardens could benefit from some good compost. If your school has a gardening project, you can easily start your own composting! Make some basic decisions to start, and you're on your way with a minimum of labor after the initial set-up. 

Location, location, location
Where will you set up your compost bin? For aesthetic reasons, you may want to hide your composting area toward the back of your garden, or out of sight around the back of the school. You may want to put in plantings to hide your compost. Make sure the location is easy enough to get to when it needs to be turned and when material is added to it. Of course, it should also be easy to get finished compost back to your gardens. Set-up
What will your composting area look like? There are all kinds of composting designs and devices. The size of the area should depend on the needs of your garden and the space available for composting.  Do you have time and the labor necessary to work a lot of compost, or is it mainly for demonstration purposes? Most people want some sort of containment device instead of a compost pile. You may want to avoid the untidy look of a simple pile, if this is in an area readily viewable by the general public. Simple, inexpensive compost bins can be made of chicken wire stapled to corner poles or stakes.  Another design uses cement blocks piled to make an easy-to-access U-shape. Make sure your design allows gardeners access to the pile when it needs to be turned or removed.

Piling it on
Who will add materials to the compost? If it is everyone in the school, you may have to educate people about what is appropriate to add, and what is not. Experts recommend adding a variety of materials: leaves, grass clippings, kitchen scraps (not meat or dairy!), and small branches.  Don't use animal waste, diseased plants, treated lumber sawdust, or weeds in your compost. If rats are a problem in your area, you will need to monitor closely the kitchen scraps added, and bury the "food stuff" under some of the non-edible material. Other sources of materials: shredded Christmas trees, grass clippings from your grounds crew, clean by-products of local industries (rice hulls from a granary, untreated lumber sawdust from a sawmill, vegetable peels from a cannery,etc.)

Working the pile
Periodically, the pile needs to be turned, or stirred up, so that aerobic bacteria can do their work in decomposing the vegetation. A properly aerated compost pile need never smell! A pitchfork works quite well, but if you are working with younger children or large groups, you may want to consider using shovels instead. There are also auguring devices available on the market. Try to turn your compost twice a week.  Turning it fewer times than that will not mean it won't work, but it will decompose more slowly. If it doesn't rain regularly in your area, water your compost periodically. You want it moist, not soggy. If you don't have much green vegetation to add to your pile, you can add a small amount of nitrogen fertilizer once or twice a year to kick start the decomposition.  

Is it done yet?
Compost is ready to distribute when it has decomposed to an even, dark brown, crumbly mix. Work your compost into the top few inches of topsoil before planting, or spread it around the base of established plants as mulch.  

Here are some links to learn more about composting:

What to Compost

Compost 101 [National Gardening] 

Environmental Information and Where to Recycle [Earth 911]