Introduction to Composting


Subject / Grade Level: Science / Pre-K

Materials: Food scraps (clean, safe for handling), dried leaves, compost bin or basket, visuals of composting, outdoor compost turner access

NJ State Science Learning Standards for Pre-K:

  • 5.1.P.A.1: Display curiosity about science objects, materials, activities, and longer-term investigations.

  • 5.1.P.B.1: Observe, question, predict, and investigate materials, objects, and phenomena during classroom activities indoors and outdoors.

  • 5.3.P.A.1: Develop an understanding of how living things interact with each other and with their environment.

Lesson Objective(s):

Students will:

  • Develop an understanding of compost and its role in nature

  • Identify items that can be composted as either “browns” (carbon-rich) or “greens” (nitrogen-rich)

  • Understand the basic needs of compost (air, heat, time) for decomposition

  • Participate in a hands-on composting activity and recognize compost as a way to recycle food waste

Differentiation Strategies to Meet Diverse Learner Needs:

  • Visual aids for vocabulary and sorting (pictures of greens vs. browns)

  • Movement and dramatization for kinesthetic learners

  • Scaffolded questioning for language learners

  • Peer modeling and guided participation

  • Allowing tactile exploration of compost items with gloves for sensory learners

ENGAGEMENT

  • Begin by asking: “Who knows what compost is?”

  • Let children share what they already know.

  • Ask questions like:

    • “What do you think happens to old food?”

    • “Why might we want to keep food scraps instead of throwing them away?”

EXPLORATION

  • Pass out “browns” and “greens” (leaves, scraps) to students.

  • Ask them to describe what they’re holding.

  • Have each child place their item in the compost bin and say what it is.

  • Teacher helps classify items as brown or green.

  • Ask:

    • “What happens when we mix these together?”

    • “What might live in the compost and help break it down?”

EXPLANATION

  • After students interact with the materials, guide them to discover compost needs. Use whole-body movement to reinforce:

    • Air: Stirring/wind

    • Heat: Pretending to be the sun

    • Time: Acting out sleeping cycles

  • Explain how these parts help break down the materials into compost.

  • Vocabulary: compost, browns, greens, bacteria, fungi, nutrient, decompose, recycle

  • Ask:

    • “Why do we need both browns and greens?”

    • “What do you think compost turns into?”

ELABORATION

  • Discuss the benefits: Compost helps plants grow by giving them nutrients!

  • Connect to their world:

    • “Have you seen big tomatoes or sunflowers in the garden?”

    • “This soil helps those grow!”

  • Take students outside to see the real compost turner.

    • Ask:

      • “Do you think this compost has air? Why?”

      • “How does the sun help this compost?”

      • “What will happen if we give it more time?”

EVALUATION

  • Observation of student participation during classification and group activities

  • Responses to recall questions (“What are compost’s three needs?”)

  • Ability to sort items as brown or green

  • Demonstrate understanding through movement and role-play (air, heat, time)

  • Final check-in: “Why is composting important?” “What do plants get from compost?”