this Daily Classroom Special:
Science to Go provides easy yet meaningful
science activities for grades k-8. Science to Go was written
by Barbara Smith, Magnet Coordinator at Harvard Elementary, Houston
(TX) and former Teachers Network web mentor.
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:
101 [National Gardening]
Information and Where to Recycle [Earth 911]