Phototropism Plant Light Maze

In this activity, students investigate phototropism - the ability of plants to grow toward light, by designing a shoebox maze with obstacles. A sprouting bean plant is placed inside, and students observe whether it can bend and grow around barriers to reach a light source. This experiment demonstrates how plants use light for photosynthesis and adapt their growth to their environment.

*Growing the plant*

1. Fill a small container (7–10 cm high) with potting mix, leaving about 1 cm at the top.
2. Plant 2–3 pole bean seeds about 2 cm deep.
3. Water daily or as needed, keeping the soil moist.
4. Place the container under grow lights or in a sunny window until sprouts reach 5–10 cm tall (3–7 days).

*Building the maze*

1. Tape any gaps in a shoebox so no light enters except through one hole.
2. Cut a square hole (8–10 cm) at one short end of the shoebox for light to enter.
3. Divide the length of the box into thirds. At the one-third mark, tape a cardboard barrier to the left side, reaching the box’s height. At the two-thirds mark, tape a second barrier on the right side. This creates a zig-zag path to the exit hole.
4. Place the sprout at the opposite end of the hole inside the box.
5. Close the lid and secure it with tape.
6. Put the shoebox so that the light hole faces a sunny window.

Make Your Own Fun Light Maze For Plants - We Are BLOOM!:

Light Mazes for Plants! - OklahomaGardening:

📄 Plant Light Shoebox Maze Experiment - Little Green Thumbs: https://www.littlegreenthumbs.org/wp-content/uploads/2020/05/Plant-Light-maze.pdf

• Make larger or more complex mazes to test the limits of phototropism.
• Try different seeds (e.g., sunflowers, peas) to compare species’ responses.
• Change the light source’s position (top, side, angled) to see how growth direction changes.
• Compare growth in a maze with plants grown in full light.

• Use scissors safely when cutting the shoebox and cardboard.
• Handle soil and seeds with clean hands, and wash hands after gardening activities.
• Ensure water does not leak from the container inside the shoebox.

• Will the sprout grow with minimal light?
• Why do plants need to move toward light in nature?
• What happens if the light is blocked completely?
• How might phototropism help plants compete with neighbors in the wild?
• What other environmental factors (water, nutrients, space) influence plant growth along with light?