How do Plants Absorb Water?

3.1 based on 92 ratings

Updated on Jun 14, 2013


Life Science

Grade Level


Difficulty Level




Safety Issues
  • Adult supervision recommended when searching the internet.
  • Watch for allergies.
Project Time Frame

2-4 weeks


This project uses a basic coloring technique that shows how plants drink water.

Project Goals
  • To demonstrate how plants drink water.
  • To discover the effects of certain substances on certain flowering plants.
  • To create a beautiful, colorful floral display.

Materials and Equipment

  • Computer with internet access
  • Color printer
  • Digital camera
  • Assorted fresh-cut flowers (should be white)
  • Several small clear glasses (or clear plastic cups)
  • Small, sharp kitchen knife
  • Food coloring (and other coloring substances – see below)
  • Typical office/craft supplies (such as paper, pens & poster-board)


Plants have a way of drawing water and other nutrients upward from below, in seeming defiance of the basic laws of gravity. This process is called transpiration. This experiment examines the process of transpiration, with charmingly decorative results.

Research Questions
  • How do plants drink water?
  • How fast do water and nutrients travel throughout the plant?
  • What are the effects of different substances in the plant water?
  • What are some advantageous uses for these effects?
Terms and Concepts to Start Background Research
  • Transpiration
  • Molecules
  • Photosynthesis

Experimental Procedure

  1. Research related materials (see bibliography below)
  2. Select at least two different types of white flowers (several specimens of each type).
  3. Do image searches online, and print out photos of the flowers you’ve selected.
  4. Obtain a dozen (or more) freshly cut white flowers with stems at least 6 inches long.
  5. Put a small amount of fresh water in each cup (about 3 tablespoons)
  6. Photograph the flowers in the cups.
  7. Add one brightly pigmented substance to each cup. You could try food coloring (20-30 drops), beet juice, grape juice, iodine, ink… Use your imagination.
  8. Carefully label each cup.
  9. Take one fresh (unused) white flower and split the center of the stem lengthwise, starting at about halfway up the stem, and cutting all the way down.
  10. Place two clean cups next to each other, with a small amount of fresh water in each one.
  11. Add 20-30 drops of blue food dye to one cup, and 20-30 drops of red food dye to the other cup.
  12. Place one part of the split stem in one cup, and the other part in the other cup.
  13. Examine and photograph all specimen(s) over the next 24-48 hours, adding a little water if needed.
  14. Preserve your specimens by drying them (optional).
  15. Interpret your results in a detailed report.
  16. Show results visually using photos taken throughout the course of the experiment.
  17. Include beautiful fresh or dried flower arrangements in your science fair display.


Wiki topic: “Flowers

Judee Shipman is a Bay Area Educational Consultant and professional writer of quality educational materials.  Her recent writing credits include (a popular and entertaining website about states), and a book called The Portable Chess Coach (Cardoza, 2006), currently available in stores.

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