Mold Terrarium: What Grows on Leftover Food?

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This activity shows you how to make a mold terrarium using a jar and leftover food. Learners explore mold, an "icky but necessary" thing that helps living matter rot, return to the soil, and provide nutrients for other plants. If you use a variety of food scraps, with preservatives and without, you'll see the different kinds of mold and be able to compare the rate of growth on various foods. Note: don't put meat or fish in your mold terrarium--after a few days, these would start to smell very, very bad.

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
1 to 4 weeks

Estimated Materials Cost:
1 cent - $1 per group of students

Age Range:
Ages 8 - 14

Resource Types:
Activity, Experiment/Lab Activity


Materials List (per group of students)

  • A clear container with a lid (Big glass jars and clear plastic containers work great, but you'll have to throw away the container when you're through)
  • Adhesive tape
  • Water
  • Some leftover food (you can use whatever is in your refrigerator), such as bread, fruit (like oranges, lemons, or grapes), vegetables (like broccoli, zucchini, or green pepper), cheese, and cookies or cake


  • Life Sciences
    • Diversity of Life
      • Protists and Fungi
    • Ecology
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations

Informal Categories

  • Food and Cooking


To use this activity, learners need to:

  • see
  • smell

Learning styles supported:

  • Involves hands-on or lab activities


This resource is part of:

Access Rights:

  • Free access


  • Murphy, Pat ; Klages, Ellen ; Shore, Linda


  • All rights reserved, The Exploratorium, 1998