Kids and Composting

Four Fun Activities for Budding Young Gardeners

When I've taught elementary-school gardening classes, the sessions about composting are always lots of fun. What I really love is that while the kids are cutting up banana peels, chasing worms and getting their hands really dirty, I know I'm also opening their eyes to the magic of soil and the basics of environmental stewardship.

Here are four projects that I have found work great with children ages 4 to 10. You can use them in the classroom or at home.

Making Soil

• Ask each child to bring in about a half cup of soil from his or her yard or garden.
• Have them spread the soil onto a piece of white paper. Using hand lenses, ask the children to describe what they see.
• Show a pie chart of soil composition (for average soil): 50% rock/minerals, 20% air, 20% water, 5 to 10% organic matter and soil life.
• Working in small groups, give each group a shoebox-size plastic container. Bring out additional containers filled with soil ingredients such as sand, stones, leaves, straw, bark, peat moss and grass clippings. Ask the kids to select some of each ingredient and mix them all together in their container. Large pieces of material can be cut or torn into smaller pieces. Add a little water, too.
• Compare the homemade soil to the soil they brought in from home and discuss why there are differences.
• Have children bring their homemade soil home and return it to their gardens or yards.

Compost Safari

• Talk about compost and the process of decomposition. Describe some of the different creatures and microbes that do the work. Discuss what they need to live.
• Bring in a 1- gallon pail of good compost and give each small group 1 cup of the compost. Have them spread it on white paper and describe what they see. Use hand lenses, if you have them.
• Hand out an informational sheet that includes drawings of some of the organisms responsible for breaking down organic matter. Talk about how to protect and encourage them.

Make a Worm Bin

• Have children bring some food scraps to contribute to the worm composting bin (banana or apple peels, bread crusts, etc.). Using scissors and butter knives, ask them to cut these materials into small pieces that are no more than one-half inch in diameter.
• Make several small worm bins using plastic storage containers with snug-fitting plastic lids. Use shoebox-size bins or make one larger bin using an 8-inch-high x 12-inch-wide x 24-inch-long container. Drill about four to six quarter-inch holes in each lid.
• If possible, line the bottom of each container with a coarse fiber mat made of coir or something similar to the material inside a furnace air filter. The idea is to keep the bedding material about 1/4 to 1/2 inch up off the bottom of the container so any excess moisture will pool beneath the bedding material.
• Have kids tear or cut lots of newspaper into strips and create a 2-inch-deep layer of strips in the bottom of the container. Sprinkle on a 1-inch layer of garden soil. Add 1 to 2 tablespoons of alfalfa meal or dried manure.
• Add a handful of food scraps. Add a small handful of red wiggler worms. (Anyone with an active worm bin can donate worms, or you can order them from Gardener's Supply.) Add another 1-inch-layer of garden soil. Sprinkle with several tablespoons of water
• Cover worm bin with lid and place it in a cool location away from light.
• Add more food every few days. Dig down a little to add food, then cover it with a little soil and more shredded paper. Don't add more food than the worms can digest, or you'll have a fruit fly problem.
• Check back every week or two to see how the decomposition is going. There should be a large increase in the number of worms.
• Finished compost will be black and crumbly. Remove it with your hands or a spoon, taking care to leave behind as many worms as possible.

Compost in a Bag

• Have kids bring in a small plastic bag with kitchen scraps such as vegetable or fruit peelings, bread crusts or pasta.
• Bring an extra supply of food scraps, as well as newspaper, dry leaves, grass clippings, old straw, coffee grounds, etc. Also have available a pound of alfalfa meal or another high-nitrogen ingredient such as Super Hot Compost Starter, and a pail of garden soil.
• Give one clear, 1-quart freezer bag to each child.
• Have children chop or tear the materials into small pieces. They can then fill their bag with a mixture of dry ingredients, garden soil, food scraps, alfalfa meal and a tablespoon or two of water.
• Seal the bags with twist ties.
• Have children massage their bags each day to mix up the ingredients. Bags should be opened for about six hours every other day to admit fresh oxygen. Then reseal the bags.
• Process should be complete in 4 to 6 weeks.
• Finished compost can be brought home for the garden or houseplants, or you can have the children put it into small cups and then plant seeds.

If you have a fun school gardening activity to pass along, we'd love to hear from you. Write to us at: innovativegardener@gardeners.com