How do Plants know which way to grow?

     If you've ever planted seeds in the ground, perhaps you have wondered just how do they know which way to grow. How do the roots know to grow down and how do the stems and leaves know to grow up?

What You'll Need:

     There are two parts to this experiment. In the first, you'll need a house plant and a few books. The house plant should not be a vine, Diffenbachia works great. In the second part, you'll need some pinto beans, a glass, aluminum foil, paper towels and a record player capable of 78 RPM speeds.

What to do:

     Take the house plant and lay it on its side leaning against the books. Observe the position of the stem and leaves over a period of one week.

What's Going On?

  Now Try This:

     For the second part of this experiment, place the pinto beans in a glass of water and let them soak overnight. Now tear 4 pieces of aluminum foil about 1 foot square. Place a paper towel in the center of each piece of aluminum foil and moisten each towel. Don't make the towels dripping wet, they should only be damp. Put four beans in the center of each paper towel and fold the foil jaround the towel, closing each end. Let the foil and beans stand for 3 days. Then space the foil pieces on the turntable of the record player and turn it to 78 RPM. Allow the machine to rotate continuously for 5 days. After the 5 days are up, turn off the record player and without changing the position of the foil, open them up and observe the beans.

Now What's Going On?

Copyright © 1997 Kathy A. Miles and Charles F. Peters II