The topic of composting is huge, and a pretty great jumping off point for about a gazillion subtopics. From composting you could easily move to exploring different types of soils, composting critters, vermicomposting (composting with worms), the benefits of organic gardening, or waste reduction/conservation. I’ll eventually post activities on all these topics, but for today I’ll start with just a couple.
How to compost:
- I like to start a small indoor compost so that students can frequently observe and record the changes occurring. You can use a boot box and line it with plastic, or just use a plastic bin with a lid. Introduce the recipe for compost: half green material, half dry brown material, water, air, and microbes. For the purposes of this indoor compost, for green material use grass clippings or green leaves. For brown material, use hay, brown leaves, wood chips, newspaper, or sawdust. Add a little bit of dirt from outdoors to add microbes to the bin. Sprinkle with water and mix. Place the lid loosely on top. You have started a compost!
- Periodically stir the bin and add water to keep it moist like a wrung out sponge. Insert a thermometer and keep a record of the temperature of the material, also recording any other observations. Use these rules to diagnose any issues:
- Provide students with a list of possible green materials, brown materials, and materials that should NOT go in the compost, in case they want to start a compost at home. Check out pages 14 and 15 of this website for a good list of greens, browns, and non-compostables.
- Make a container to collect kitchen compost materials at home for home compost piles.
- Read the book Compost Stew, by Mary McKenna Siddals
- Play this online game where you must keep the microbe happy in the compost pile by adding appropriate ingredients
- Place one of these posters about composting in your classroom
- Watch the short video, Creatures of the Compost, to learn about critters that help the compost in an outdoor compost pile.
- If you have one, explore the outdoor compost pile to find and examine compost critters. Use this critter id form (on the last page of the pdf). There is also a crossword puzzle at that link which can help when learning about compost critters.
- Alternatively, go to a forested area thick with leaf litter. The leaves are decomposing and creating compost on the forest floor (although with less green material it takes much longer). Split your class into groups, provide each group with a tray or bin, a shovel, a magnifying glass, and a critter id form. Tell students to place a little of the leaf litter in their bin as well as a small shovel-full of the composted dirt. I like to tell students to record/draw EVERYTHING they find, classify it as organic (it once was alive) or non-organic material and identify any critters found.. Expect students to find seeds, dead leaves, soil, rocks, roots, critters, and more. Use the critter ID form (found on the last page of the pdf).
- MyMove™ – Indoor and Outdoor Composting How To Guide (mymove.com)