Preparation

• For science projects with changing flower colors, you need white carnation flowers, slender glass vases, food coloring in red, yellow, blue and green, a knife and water. Kids do need help from an adult during this experiment. The glass cups or vases are important so you can see the colors being fed to the flowers, but you can also use plastic cups. You will need 24 hours of observation for this experiment.
  
  

The Experiments

• Begin by filling each cup halfway with water. Then add 20 to 30 drops of food coloring to each cup. Trim the stem of the flowers at an angle for a fresh cut (an adult needs to handle the knife). Place some of the cut flowers in cups of colored water, reserving a couple for the second experiment.
  
  For the second experiment, slit the stems of the remaining flowers straight up the middle, but stopping a few inches below the flower head. Place two glasses, with different colored food dyes in each, next to each other. Gently separate the slit stems, placing one side in one glass, and the other in the different glass.
  
  

Hypothesis and Questions

• Develop some predictions and a hypothesis about the science project. Ask questions about what happens in the experiment. How long does it take for the colors to soak into the petals? Do any colors show up faster than others? Will split stem flowers absorb the same way as regular stem flowers? For the split stem experiment, which side of the flower will one glass's water migrate to? You should check the flowers every few hours in order to answer these questions.
  
  

Observation and Conclusion

• As the water travels up the stems, you notice the petals changing colors according to the food coloring in their drinking supply. This is a process called "transpiration." Plants suck up water through tubes called "xylem," which are vein-like structures in the stems and leaves. When observing how the dye moves through the flowers, you might notice that blue dye moves through the plant the fastest, followed by red and green dyes.