Gather:

   

1. •    Milk cartons, plastic bottles or other similar containers
   

2. •    Potting soil
   

3. •    Water
   

4. •    Kitchen seeds like beans, popcorn or raw sunflowers
   

5. •    Scissors
   

6. •    Paper and pencil
   

7. •    Ruler
   

8. •    Permanent pen such as a Sharpie
   

Explore:

Think about what plants may need to grow. Design an experiment to test some of your ideas. For example, you might try watering some plants, and not watering others. You could keep some in the dark by covering them with a cardboard box and keep some in the light. What about fresh air? Could you put some of the plants in tightly sealed plastic bags to see if they need fresh air? Can you leave out the soil? Can you grow plants in a kitchen sponge or wad of moist paper towels instead of soil? Decide how many seeds to plant in each container. Do plants grow better alone, with a few other plants, or with a lot of other plants? See the example experiment for one way to set this up.

Write down your experiment. Figure out how many containers you will need. Cut off the tops of the milk cartons or plastic bottles with scissors. Poke a few drain holes in the bottom. (If you want, you can leave drain holes out of a container to see if you really need drain holes.) Label each container with the permanent marker so you can remember which treatment it is.

Fill the cartons with the soil or growing medium you have chosen. Plant the seeds. Water those you have chosen to receive water. Cover the ones that are to be dark, wrap in plastic those that are not going to get fresh air. Check every other day to add water as necessary and record your results by measuring the height of each plant. Which plants grew best? What conditions do plants need for proper growth?

Can you think of any other variables to test? What about hot versus cold temperatures? What about giving some plants fertilizer and other none? Carry out your experiment and record the results.