Plants and Gravity
This lesson developed by Reach Out!
Recommended Age: Later Elementary and Middle School
What effect does gravity have on plants?
- 12 bean, sunflower or pumpkin seeds
- Pie pan
- Measuring cup
- Coffee filters or blotting paper
- 2 pint-sized clear glass jars
- Roll of paper towels
- Table or ledge area near a window with plenty of sunlight
What to do:
- Put water into the pie pan.
- Place your seeds into the water. Let them soak overnight.
- Cut two pieces of coffee filter or blotting paper so it will fit and
line the pint jars.
- Line the inside of both jars with the coffee filter or blotting paper material.
- Crumple up paper toweling and place in the middle of the glasses.
toweling will keep the coffee filter or blotting paper in place and
also absorb water.
- Fill you measuring cup with water. Saturate the toweling and the
coffee filter or blotting paper in each glass container with water. Pour
off any excess water. You shouldn't see any standing water in your
- Poke down six seeds in between the glass and coffee filter or blotting
paper in each jar. Spread them out. Put them down about half way into
- Place both jars on the table top or ledge that is near a window with a
direct source of sunlight.
- Make sure to keep adding water as you need to in order to keep the
toweling and coffee filter or blotting paper moist.
- Watch what happens in about a week. You should see the seeds
sprouting and germinating. Little baby plants should start to grow with
roots, stems and fragile leaves.
- Set one of the jars on its side. You may need to put some wadded up
paper toweling on one side to keep it from rolling off the table top or
- Watch what happens in a few days!
What is happening?
Plant stems and leaves grow in the direction of light but also away from the center of the earth's force of gravity. You should see that the little plant seedlings in the jar layed on its side will turn on their stems and try to grow upwards again.
They won't grow sideways or downwards.
We call what is happening "negative geotropism." This means that plants grow and move away from the force of gravity.