A Backwards Garden

CoGarbagentributed by: Tara Webb

Grade 7: Life Systems

… Making our own little bit of paradise

  • Ecosystems are made up of biotic (living) and abiotic (non-living) elements, which depend on each other to survive.

  • Ecosystems are in a constant state of change. The changes may be caused by nature or by human intervention.

Inquiry Skills Used

Observe and record, analyze and apply. If the student is doing an observational study related to the technique, it could also include hypothesize and relate.

Safety Considerations

During the mixing and shaking, personal protective equipment (PPE), such as safety glasses or goggles, should be worn. Do not allow students to pour these soil mixtures down the drain at the end of the data collection period as it will clog drains. Samples should be returned to where they were taken from or gently swished out into flower beds or on the school field.


Tons of garbage is taken to landfills on a daily bases.  How much of that garbage actually decomposes and how much will remain in the landfill for generations to come?  The purpose of this experiment is to plant garbage outside and see what disappears. The garbage should disappear faster in the containers with soil from outside.  This is because there are more organisms in the outside soil.  It is the organisms in the soil that break down the garbage.

What You Need

  • An area of land outside
  • Garbage (decomposable and non-decomposable)
  • Shovel or spade
  • Markers – sticks or rocks

What to Do

  1. Recommended to be done in the spring or fall.
  2. Select a site to bury the garbage.
  3. As a class, describe the site.
  4. Make a list of the garbage that you are going to plant.
  5. As a class, create a chart with the first date being the day you plant the garbage.
  6. Using the shovel or spade, dig holes in the ground.
  7. Plant one piece of garbage in each hole.
  8. Put markers up so you know where you planted the garbage.
  9. Water the garden.
  10. Leave for a month.
  11. Dig up garbage and record what you see on your chart.
  12. Repeat steps 6, 7, and 8.


Where to Go from Here?

  1. Compare your Backwards Garden to your landfill in a jar; is there a difference in how fast items degraded?
  2. Why do you think some items decomposed faster than others?
  3. What are the decomposers in the soil?
  4. Why did some items not decompose?
  5. What was the impact on the environment of the Backwards Garden site?
  6. Which items decomposed the biotic or abiotic?

STSE Links

Many people recycle because it makes them feel that they are doing something good for the environment. But the focus on recycling takes the emphasis away from strategies like reducing or reusing.

Cross Curricular Connections


  • Use the book, Wolf Island, as a model. Create a picture book that looks at the interactions in the natural environment, and identify factors that affect the balance between different components of an ecosystem.
  • Examine Aboriginal stories that imbed the principles of sustainability. Have students create their own modern day legend using their knowledge of the biotic and abiotic elements of the environment and Aboriginal perspectives on sustainability.


  • The students can measure mass and volume.

Credit Where Credit is Due

This activity is also demonstrated in the ScienceWorks workshop, Interactions with the Environment.




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