Hooray for May! May brings all kinds of interesting holidays and nature events, including bird migration, the celebration of Amelia Earhart’s solo flight across the Atlantic and of course, Mother’s Day. Spring is in full swing and what a better way to celebrate than examining the way a flower absorbs water? Head to the store and grab a few carnations to learn about the importance of the stem in sustaining plant growth. You can even create your own special bouquet for a gift.
1. Start by mixing 10 drops of food coloring of your choice in clean, fresh water in the cup or jar. You can try with one jar or many. If using multiples, try a different color in each jar.
2. Then, cut off 4 – 6 inches from the bottom of the stem of your flower.
3. Place the cut flower in the jar or cup, and put it in a location where it can get sunlight.
4. Make predictions on what will happen to the flower. Write down your predictions to evaluate at the end of your experiment.
5. Observe the flower over time and within a few days, or even hours, you should see the color begin to change in the petals of the flower. How many of the petals changed color in one hour? How many changed in one day? Which color was absorbed the fastest?
That’s Cool! What Happened?
Most flowers absorb water through the roots and into the stem to support the plant. Without roots, the stem still absorbs the water. As water evaporates from the leaves, buds, and petals, the flower pulls more water up through the stem to feed itself. This is called transpiration.
Ask an adult for help splitting the stem into multiple, vertical sections. Place each section in a different color of water and watch what happens. Steve Spangler Science suggests keeping a “control” jar with clear water to watch the differences in color and texture as the experiment progresses.
Try different kinds of white flowers to see transpiration in action with various plants.