See How They Grow

What is your favorite food to eat? How often do you eat it? Do you think you would like to eat your favorite food every day? Would you like it if you didn’t have to eat anything but your favorite food?

We all have favorite foods we like to eat, but what do you think would happen if you ate only one thing?

It is okay to have favorite foods, but we need to eat different foods so we can get different vitamins, minerals, and other good things we need to keep our bodies in good shape.

Other living things need to eat different healthy foods, too—even plants and trees.

When we think of food for plants and trees, the first thing we usually think of is dirt. Dirt is one of the main food sources for plants and trees. Dirt has vitamins and minerals plants and trees need in order to grow and to be healthy. But dirt is not the only food plants and trees need. They also need sun and water. In fact, without all three of these ‘favorite foods’, a plant cannot be healthy or even survive.

To show you that this is true, let’s see how they grow….

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  • Potting soil
  • Cotton balls (2 or 3)
  • Dried beans (8)
  • 4 small jars (baby food or jelly-sized canning jars)
  • Water
  • Sunny window sill
  • Dark place (closet, garage, basement)
  • Pen and paper or camera


  • Place 2 inches of potting soil in two of the jars.
  • Water the soil so that it is wet, but not muddy.
  • Place 2 beans on top of the soil in each of the two jars and cover with a spoonful or two of potting soil.
  • Sprinkle enough water on the soil to make it moist, but not too wet, and label these jars JAR 1 and JAR 2.
  • Place two or three cotton balls in a jar.
  • Get the cotton balls wet—it is alright if there is a little bit of water in the jar with the cotton.
  • Place 2 beans on the cotton balls; moving one of the cotton balls on top of the beans and label this jar, JAR 3.
  • Put 2 beans in the bottom of the last jar and add enough water to barely cover the beans and label it JAR 4.
  • Put all four jars in a sunny window sill.
  • Use a camera or pencil and paper to take/draw a picture of your jars and beans.
  • Check the jars each day; keeping the soil or cotton moist, but not wet.
  • As each jar sprouts, take (or draw) a picture of it.
  • When JAR 2’s plant is 2 inches tall, take or draw a picture of it and put it in a dark place, and continue to water as needed.
  • When JAR 3’s plant is 2 inches tall, take or draw a picture of it, leave it in the sun, but stop watering it.
  • Leave JAR 4 where it is; adding a teaspoon of water every day until the jar is full.
  • Every other day, write down any changes you notice in the plants.
  • At the end of two weeks, take (or draw) another picture of each plant.
  • If any plant dies, write down which jar the plant ‘lived’ in and throw it away


JAR 1 and JAR 2 started out with everything a plant needs—soil, water, and sun. JAR 3 and JAR 4 were both missing soil, even though JAR 3 had ‘fake’ soil.

With at least two of a plant’s main foods, all beans were able to sprout. But as the beans began to grow, their need for all three foods a plant needs to live became stronger. You could see this in the size, color, and shape of the plants and the rate they were growing.

As the plants continued to go without the food they needed, they stopped growing and died. Only the plant that received the right amounts of water, sun, and soil grew strong and healthy.


  • Repeat the experiment putting all plants in the dark to see how long it takes them to sprout.
  • Try the experiment using different types of seeds.
  • Try the experiment using only cotton instead of soil, but give them the right amounts of sun and water.