Do Plants Grow Towards Light:
Biology Science Fair Project on Phototropism
Do Plants Grow Towards Light This is a good science fair project that investigates a property of plants known as phototropism: that is, their ability to grow toward light sources wherever they may be. You may be surprised at how clever these plants can be, even without a brain
- 2 small potatoes with buds (so that they can sprout)
- 2 small planting pots
- scissors or a sharp knife
- empty cardboard box with lid (shoeboxes work well)
- 3 pieces of cardboard
- a shelf sunlight and warmth
Do you think the potato plant will be able to navigate the maze you set up? If so, how do you think it will manage this? If not, how far do you think it will get?
- Put the potatoes in the sun for a couple of weeks so that their buds (also known as “eyes”) can grow
- While you are waiting, prepare the shoebox: cut a hole roughly 2 inches x 2 inches in one of the narrow ends. Cut the pieces of cardboard so that they are the same height as the box (touching the lid when stood on end) and about 2-thirds of its width.
- Tape the cardboard rectangles to the inside of the box in an alternating pattern to make a curving maze. Make sure that no direct light can get from the hole to the other end of the box. Leave enough room in one end for the small pot containing a potato.
- Once the buds have grown, place each potato in a pot. Cover them with soil so that the largest bud is just above he level of the soil.
- Place one of the pots in the box. Cover the box with the lid. Put the other pot next to the box, so that they both get the same amount of sun and warmth.
- Water both plants regularly. When you water the plant in the box, do so only at night with all lights off so that you do not let light in through the top of the box.
Come back in two weeks to measure the length of each potato sprout. Which one grew faster? Did the one in the box grow through the maze, or was it stunted? Was your hypothesis confirmed?
*TIP: You can try these good science fair projects with many different kinds of plants. Ask your gardener or nursery staff for advice!