With spring around the corner, I wanted to do a science experiment with my class that would show them a little bit about how flowers ‘drink’ water and how different substances are best to keep a flower alive. This is a very simple STEM science activity that kids will love watching and checking while the different liquids and materials take effect on the flowers.

For young preschool or kindergarten aged children, the experiment is exciting to watch as some of the flowers change color and some of the flowers wilt much faster than others.

For older children, the experiment makes learning about capillary action, osmosis and plant nutrition easy to understand and fun to learn about. You can go into as much, or as little detail as you want for the experiment.

I chose sixteen different substances to each fill a test tube with. I then put a flower into each tube. Below you will find free printable labels for the sixteen materials I used, however, you can use any substances you want, or have on hand.

The purpose of the experiment is to examine the effects of different substances, so as long as you use a variety, there will be a lot of learning that comes from your experiment.

For another popular experiment that uses flowers, check out a Simple Science Experiment with Flowers from Hands-On Teaching Ideas.

STEM Science Activity Materials

There are a lot of substances you need for this experiment. On the free printable labels, there is an image and the word for each material you can use to fill each test tube with. However, you can use any materials you want. The printable also includes a blank label that you can add your own list of substances. For this experiment, you will need:

• Test Tubes
• 16+ liquids or substances to put in each tube (Things like honey, water, soil, glue etc.)
• Substance Labels (Free to download at the bottom of this page)
• Flowers

I used test tubes because I had some on hand, but using cups or any other container will also work. If possible, use clear containers so that children can see the substance inside. If you are able to use test tubes, they add to the experiment because kids feel like real scientists.

I also chose to use white flowers because I wanted the tubes with food coloring to show on the flower. Use any flowers you have. I suggest using the same type of flower for each tube to help with consistency with the experiment.

For more hands-on experiments, make sure to visit the huge collection of 81 Easy Science experiments and 60 Best STEM Activities for Kids.

Science Experiment Steps

Start by cutting the flowers each roughly the same length. Make sure to keep some of the stem so that it goes into the substance in the test tube.

Fill each test tube with a different liquid or material. The substances I used were the things that my kindergarten students wanted to test. They each gave an idea for a tube.

Place a flower into each of the test tubes, and then wait and watch. Nothing will happen right away, so it is a great time to have kids predict what they think will happen. Will the flower change color, wilt right away or stay upright in bloom for a long time?

After roughly an hour, the flower with the food coloring will begin to show some of the color in the petals. This is a great chance to talk about how the stem/flower is ‘drinking’ the liquid food coloring and bringing it up and throughout the flower.

Flowers absorb the liquid through their stems through capillary action. This process allows water to travel up through the tiny tubes in the stem. We see this when we see the color throughout the flower and petals.

Keep an eye on the flowers during the day. Depending on the substances you use, as well as the type of flowers, you may not notice any other remarkable changes the first day.

STEM Science Activity Results

After a few days, the changes become more noticeable. Several of the flowers begin to wilt, whereas others may show little to no change.

I removed a few of the test tubes and flowers for my pictures below to show some of the changes. The flower in the test tube with the salt was the first flower to begin to wilt. It quickly began to droop and the petals began to fall off.

This is a great example to demonstrate osmosis to kids. Since there is so much salt in the water, the flower can’t suck up the water properly in order to live. The salt water also draws water out of the flower’s cells, which also causes it to die.

A few other interesting observations my students and I noticed after a few days were the following.

STEM Science Activity

The flowers in acidic substances, such as lemon juice and vinegar were some of the first to start wilting. The test tubes with materials that didn’t have a lot of liquid, such as slime and dirt, did not kill the flower right away, but these flowers did begin to wilt faster than others.

The flower in the pop (coke) began to shows some of the brown color in it’s petals in a short period of time. The flowers in plain water were in the best shape after a few days.

I was surprised to find that most of the flowers after the first day had barely changed. I thought the effects of the liquids, like the vinegar, would have been apparent much faster.

Many of my students guessed that the flower in the soil would last the longest and stay in bloom the longest, however, without any water, the soil on it’s own did not help the flower survive. This was a great way for children to see that although soil can be good for growing flowers, a combination of thing are needed to really make the flower flourish.

STEM Science Activity for Kids Extension

Although my students got to choose which substances we put our flowers in, I had extra flowers and my students had extra ideas of what they wanted to test.

If you let your children decide about the substances, you will find they are more engaged in the activity. They can choose anything they can find. Encourage different ideas and even if a material seems unusual, or you know what the outcome will be, it’s a great opportunity for children to learn through their own exploration.

Beyond the sixteen substances listed on the free labels, we also decided to test a few materials from around the classroom, such as, orbeez in food coloring, milk, oobleck, pop (sprite), hand sanitizer, paper, soap, paint and coffee.

This project is a great and beautiful experiment that kids, and even adults, will love checking throughout the day and weeks as you do the experiment. I hope through this exploration children will learn, and remember more about plant nutrition and preservation.

If older children are doing the experiment you can discuss how the type of flower can have an impact on the experiment and other simple things like the temperature of the substances. If you leave the flowers in the substances for several weeks you may also begin to see some bacterial growth, especially in the sugary substances. All of these changes are great observations and learning points.

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