What You Will Need

• Red Wiggler worms, 1-2 pounds (1 pound = approximately 1,000 worms)
• Two 12-to-14-gallon plastic opaque storage containers with tight-fitting lids
• Drill with a small drill bit
• Potting soil - 2-4 cups
• Food scraps from fruits, vegetables, grain products and coffee grounds (do not use dairy, meat, or oily items)
• Colander
• Large plastic bowl
• Plastic spray bottle filled with water
• Disposable gloves - a pair for each child and adult
• Large amount of newspaper torn into ¼” strips
• Plastic sand shovels or large plastic spoons - one for each child
• Flashlight
• Water

What To Do

Note: This lesson creates an ongoing activity. You will prepare the compost bin as one activity, care for the worms daily, and harvest the soil in about 3 months.

1. Begin a conversation about farmers. Discuss where they work and what they do. Explain that you will be exploring what farmers and gardeners do to create healthy, rich soil for their plants.
   
2. Have the students help you tear the newspaper into strips.
   
3. Place the strips of newspaper into the large plastic bowl and cover them with water.
   
4. Allow the newspaper strips to soak in the water for a few minutes.
   
5. Remove the newspaper strips from the bowl and place them in the colander to drain. When done, they should be damp but not dripping with water.
   
6. While the newspaper is draining, drill 10-12 air holes (about one-third of the way down from the top edge) all the way around the containers. 
   
7. Drill holes for drainage in the bottom of one of the bins.
   
8. Place the bin with the holes in the bottom inside the other bin. 
   
9. Invite the children to fill the inner bin about one-third full with the wet newspaper. 
   
10. Let the children use the sand shovels to scoop the potting soil into the bin.
    
11. For children who are comfortable, let them add the worms and food scraps. Every pound of worms will need one pound of food per week.
    
12. Take turns gently mixing the contents. Try to make sure all the food is buried under the dirt so you will not attract fruit flies. 
    
13. Cover the whole mixture with about an inch of dry, torn newspaper. 
    
14. Use the water bottle to spray the top layer of newspaper. Moisten the paper, but do not soak it.
    
15. The container should be kept in an environment with a temperature between 55 and 77 degrees.
    
16. Caring for your worms, see Lesson Tips (at right).
    
17. Harvesting your composted soil: See the section below titled “Harvesting Your Composted Soil” for steps on how to harvest the soil.

Guiding Student Inquiry

• Have you ever visited a farm?
• What kind of things can you find on a farm?
• Do you know what the farmer does at the farm?
• What kinds of plants might be on a farm?
• How do farmers take care of their plants?
• Show the children one of the worms. “Let’s look at this (show them a worm), have you ever seen one of these before?”
• Where did you see it? What was it doing?”
• Do you know what this is?
• Tell me about it. What does it look like? How does it feel?
• Will it hurt us or is it gentle? How does it eat?
• How do farmers help our community?

Explore, Extend & Integrate

• Provide opportunities for the children to observe and document what they see as they create and use the compost bin. Leave clipboards and crayons or markers near the composting bin so the children can draw and “write” their observations.
• Create interactive charts and graphs where the children can record important information, such as when or what the worms have been fed.
• Add tasks, such as collecting food scraps or spraying the compost bin with moisture, to your job chart.
• Collect worms from the playground, place them in your discovery center, and let the children compare them to the worms in the compost bin (release the worms back to the playground when you are done).

Check for Children’s Understanding

• Can the children talk about what the worms did with the paper and food?
• Were the children able to recognize the connection between the food scraps, worms, and compost?
• Did the children understand that farmers “feed” their plants with compost?

Resources

Harvesting your Composted Soil

1. You will know your compost is ready for harvesting when there is more compost and less bedding. This typically takes about 3 months.

2.  Spread a thick plastic tablecloth on the ground outside. If you are doing this inside, lay the tablecloth in a plastic baby pool to keep the compost contained.

3. Anyone handling the compost should put on disposable gloves.

4. Remove the mixture from the composting bin and mound it in a pile on the tablecloth.

5. Shine the flashlight on the pile. The light will drive the worms to the bottom.

6.  Now harvest the compost. Small lemon-shaped pieces of soil are actually worm cocoons; be sure to add these along with the worms back into the worm bin. 

7. Return the worms and some of the compost to the original bin. Mix them with fresh potting soil, newspaper, and water, as if you were starting over. 

8. Use the collected composted soil. The children can mix it with potting soil and use it to plant seeds or bulbs in pots or create an outdoor garden of flowers or vegetables.

Resources

Lesson Tips
Books^[1]
Home/School Connections
Las Conexiones a la Casa