How does saltwater affect seeds?

Early in the school year, fourth graders did an experiment to see which kind of potting soil helped to grow the biggest plants. (We found that the seed starter is the best!)

Now, as we get ready to study different kinds of water habitats, we're examining the effects of salt water. Will saltwater help plants to grow, or harm them? To test this, we're planting seeds in the same kind of soil and watering some with tap water, some with slightly salty water, and some with very salty water.

Before we planted our seeds, students used their prior knowledge to make a hypothesis. Many of them had an idea about what the very salty water would do. But what about the slightly salty water? See what your child thinks!

Once we formed our hypotheses, we planted the seeds. We used radish seeds because they grow quickly and are easy to handle. Watering the seeds gave students another chance to practice using the graduate cylinders!

What will happen? We'll find out! Talk with your child about the experiment. What is your child's hypothesis?

If you used salt on your driveway this winter, how might this affect plants? What about plants that grow along the beach--does the saltwater have an effect on them? Why or why not?

If you are interested in learning about some mystery seeds, visit this fun science blog. Look for updates on our radish seeds!