Experimental Gardens
Explore How Variables Affect Plant Growth

After planting your official test garden according to protocol, explore how different variables could affect plants by asking "What if..." questions and planting experimental gardens.

Essential Question:
What variables could significantly affect
how tulips grow?

1. Ask "What If....?" Questions
After you have planted the official test garden according to protocol, ask questions that encourage students to wonder what would happen if they broke the rules: What if we planted the bulbs at different depths? What would happen if we planted the bulbs in full shade? As a class, brainstorm a list of questions related to how variables could affect tulip growth. Review the importance of controlling variables in a scientific experiment as you discuss why protocol is necessary for test gardens: to ensure that all variables are treated the same way in every garden. The only difference between the gardens is the location.

2. Identify Testable Questions
Have students review the list of brainstormed questions to find 1-3 questions they would like to explore further by designing and planting experimental gardens. Encourage them to think about which variables are testable. Challenge them to think about how to control variables in order to scientifically document through experimental methods.

3. Design Investigations to Find Answers
Divide students into groups. Let members discuss which questions most interest them and then decide on one to explore. Allow younger students to try out their ideas. Remind older students that they should test only one variable (e.g., planting depth) at a time. Use the journal page to organize each group's plan for their investigation.

4. Plant Experimental Garden Plots
Plant an experimental garden plot to test each question you'd like to investigate. You can later compare outcomes to your official Journey North garden, which will serve as a "control." Make sure you have a good label system to identify the different experiments.

5. Journal
Revisit the journal page in late winter or spring after observing their experimental plots and comparing them with their official Journey North gardens. Wrap up the experiment with a conclusion and a report of the results.

6. Important: Next Spring
ONLY report to Journey North about your Official Journey North garden. Use the "Comments" section of your report to tell us what you learned from your experimental garden plots.

official garden
Official Garden

Journal page
Journal Page

planting at base of tree
Planting around tree