Explain the importance of a root. Remind your children that while they eat with their mouths, a plant "eats" through its roots. Without strong, healthy roots, a plant cannot grow and thrive.
Make a list of fruits, vegetables and common plants your students are familiar with. Ask if they can discern and figure out which plants have roots. For example, carrots have roots but apples do not.
Show your children a plant that still has its roots attached. Let them touch and explore the plant. Talk about how the top of the plant, which grows above the earth, feels differently than the roots, which grow under the earth.
Hang a picture in your classroom of a plant. Label each part of the plant, including the stem, any leaves and the roots. Show your students the picture and talk about how the drawing looks compared to the live plant they saw.
Grow a plant in your classroom. Let your children pack dirt into a clear, plastic cup and plant a seed. Water the seed and watch it grow. Your students will be able to see the roots against the plastic cup as the plant grows. When the plant becomes too big for the cup, transplant it to an outdoor park or garden.