Education:Science Projects: Reaching for the Light
Gather the things you'll need first.
Wrap the sponges around the roots and soil after removing the plant from the pot.
Hang your plant upside down near a sunny window. Keep the sponges and soil moist and watch what happens.
Most plants need light to survive and grow. It's an important part of photosynthesis, the process plants use to make their own energy. Without any light at all, most plants wouldn't do very well, and many would die. See just how strong a plant's need for light is!
What you need
• a small upright potted plant (not one with a lot of leaves that hang down) with a strong root system
• two large sponges, or three medium sponges
• string
• water
What you do
1. Carefully remove the plant from its pot, trying to leave as much soil on the roots as possible.
2. Wet the sponges, then wrap them around the plant's roots and the dirt. Tie them together with string to keep them around the roots. (You'll need someone to help you with this step!)
3. Turn the plant upside down, so the sponges and roots are at the top. Hang it by the string from a hook in the ceiling near a sunny window. Check the sponges, and keep them moist.
4. Watch what happens over the next several days.
Why this happens
The leaves and stems of plants will always grow in the direction of a light source. This process is called "phototropism." So even if it has to twist in some odd directions, the plant will keep reaching for the light! That's one way that plants grow and replenish themselves in forests: when an old tree dies, it leaves an open space where more light reaches down to the forest floor. Then small plants down there start growing, reaching to get as much of that light as they can.
