Tomorrow is St. Patrick’s Day. Here is a fun green homeschool project that you can do today, to enjoy green-tipped flowers tomorrow.
This project will visually demonstrate how the transport system of a flowering plant works. Specifically, that water moves up vessels in the stem of a flowering plant, and along with water, other liquids are able to travel to the cells of a plant. (You can talk about how this process allows nutrients to get into crops when rain and nutrients in the soil come together and travel from the roots into the vessels of a plant to feed it.)
What you’ll need:
- One or more white carnations (other white flowers will work, as will freshly-cut stalks of celery, but carnations might produce a lovelier and more vivid result)
- A clear glass or vase
- Green food coloring
Here’s what you do:
- First, study one of the carnations. Ask your child what they think will happen if the flower is put in colored water.
- Will the whole plant change color?
- Will just the petals change color?
- Will they change color all the way, or just at the very tips?
- Fill your jar or vase up with water, then add several drops of food coloring — until the water is a dark green. (Probably at least 10, but even more if you want a darker result.) Two things to keep in mind:
- Do not add any plant food that may have come with the flowers before conducting this experiment. It will negatively affect the final result.
- The intensity of color in the white petals will be dependent on how dark the liquid is, so you’ll want the liquid to be a bit darker than your desired petal color.
- Cut the ends off of the stems just before putting them into the water, then put them into the jar and leave them for a day, or up to a week. (Here’s a variation: Don’t cut the stem off of one carnation if you’d like to observe how not doing so might affect the final color result, and therefore the plants ability to take in water from the vase.)
- Observe the flowers and notice how the coloring travels up the stems.
What you’ll observe:
- Dye travels up stem and eventually settles in the petals, demonstrating how the vessels in a plant are much like straws in a glass of lemonade. These same vessels will develop air bubbles in the end (at the cut part of the stem) which seals in water when the plant is cut.
- If you split the stem lengthwise down the middle just before plunging them in water and allow each half of the stem to rest in two different glasses of different colored water, you’ll initially observe each side of the flower showing only its respective color, but eventually, all parts of the flower will show both colors. This is due to the xylem vessels in a flowering plant’s water transport system that allow water to move from side to side, in case one vessel is blocked. This helps ensure the flower gets adequate hydration.
- If you didn’t cut the end of one stem, you’ll notice it doesn’t look as vibrant as the other flowers, and also that it hasn’t developed color the same way as the other flowers. This is a good opportunity to explain how the ends of cut flowers seal at the ends when they are not in water in order to preserve the moisture that is already in them.
- The water will have changed at the end of this project. How?
- Set up several glasses of water with various different colors. You’ll end up with multi-colored carnations.
- Split one carnation lengthwise down the middle and put each half of the stem in a different glass with a different color of water. Note: Stop several inches from the blossom – you’ll only need to cut enough inches up the stem to allow it to still stand up in a glass or vase.
- The Everything Kids’ Easy Science Experiments Book
- Everything Kids’ Magical Science Experiments Book: Dazzle your friends and family by making magical things happen!
- Janice VanCleave’s 201 Awesome, Magical, Bizarre, & Incredible Experiments (Science for Every Kid)
- Green Thumbs: A Kid’s Activity Guide to Indoor and Outdoor Gardening (A Kid’s Guide series)