Heat Sources - Energy to Grow!
All living things use heat and light from the sun. Plants need sunlight to make food. What do you think will happen if plants don't get enough sunlight? Try this experiment to find out.
Materials:
- Three paper cups
- Seeds to plant: grass, alfalfa, lima beans, etc. (use only one type of seed)
- Potting soil
- Box
Procedure:
- Fill each cup about 2/3 full of soil.
- Plant the same number of the same kind of seeds in each container.
- Use the same amount of water to moisten the soil.
- Set your containers in the same place using the same amount of water until the plants have grown 3 - 5 cm tall.
- Draw and color what your plants look like.
- Test the effect of light on your plants:
- Place one plant in full sunlight.
- Place one plant where it gets partial sunlight
- Cover the final plant with the box (so it is in the dark.)
- Keep the temperature about the same.
- Keep your plants watered with the same amount of water.
- Observe your plants every day and draw the changes you see.
Analysis:
- After two weeks, how are the plants different?
- What effect do you think sunlight has on how plants grow?

