Composting at Schools

Janice McPhillips

Holly Hill Farm

Cohasset, MA

What is compost?

• Decomposed organic matter (leaves, manure, kitchen scraps, grass and other yard waste), also known as humus

• The process of decomposition of organic matter into humus

Why bother making compost?

• recycling spent resource into a useful one

• saves on garbage disposal costs (transportation, bags, dump fees, etc.)

• creates a valuable organic material for the garden for free (almost)

• learning about decomposition, soil structure, and returning nutrients to the soil

What makes compost happen?

• microorganisms including bacteria, fungi, and molds

• earthworms

• insects including spiders, beetles, pill bugs, millipedes, and more

• air, water, sunshine, occasional mixing, and time

How can you compost at your school?

• interested and committed teachers, administrators and custodial staff?

• cooperative kitchen staff?• parents or other volunteers?• help the students “own” the process!• find a convenient site (near the garden, or

cafeteria)• ideal site should be partially shaded, near

water source

How do you get started?

• get a free compost bin from MA DEP (www.thegreenteam.org)

• get a free compost bin from your town DPW or local garden club

• make a bin out of pallets or chicken wire or other containment system

• buy or make a worm bin for indoor composting

What can you compost?• lunch scraps • cafeteria food preparation scraps• coffee from the teachers’ lounge• leaves and garden waste including grass

clippings• straw, hay, or shavings• some paper and cardboard• sawdust• cow, chicken, or horse manure

How do you make an outdoor compost pile?

• layers of “brown” (carbon-rich) and “green” (nitrogen-rich) materials, about a 3:1 ratio by volume

• add a shovelful of soil every 8-12”

• water

• stir frequently

Nitrogen and Carbon sources

Nitrogen-rich materials:

food scraps including coffee grounds

manures

seaweed

grass clippings

Carbon-rich materials:

leaves

sawdust

newspaper

paper towels

straw or shavings

Do NOT to put into a compost pile:

• meat, dairy, bones, fatty foods like salads with dressing or peanut butter

• dog or cat waste

• weeds that have gone to seed

• diseased plants

• weeds that spread with runners

How long will it take to make finished compost?

• depends on temperature, what you put in compost, moisture, size of pile, how often it is turned

• can take as short as 12 weeks or as long as 1 year

What can students learn from having a compost pile at your

school?

• math concepts

• observing and writing

• predicting

• microorganisms, earthworms, insects, pH

• vocabulary

• food web: producers, consumers, decomposers

What can go wrong?

• attract unwanted animals

• bad smell

• fruit flies

• students putting things in compost that don’t belong

• SNOW!

Make or buy a worm bin for indoor composting

How do you make a worm bin?

• buy a Rubbermaid Tough Tote• drill 1/8” holes every 3” around the bottom and in

the cover• start with a damp layer of carbon rich “bedding”

material like leaves, straw, or shredded paper• layer “greens” and “browns” in the same way

you would for an outdoor bin• make sure to bury food scraps under a layer of

bedding to prevent fruit flies• add red wiggler worms

Need more information?

www.mass.gov/depor

www.thegreenteam.org

Ann McGovern

ann.mcgovern@state.mass.us

(617) 292-5834