Environmental Learning Gardening Q & A Green Schools & Classrooms Lessons To Grow! Pure Science

Preschoolers, Scientific Method & Baby Plants

Preschoolers Do The Scientific Method with Seedlings.

Kids are asking great questions about plants at Christ Lutheran Church Preschool and Childcare Center in Blaine, Minnesota.  In class they have been learning about seeds, plants, and one classroom’s even growing cilantro for their classroom Bunny named Louie.  Students, teachers and volunteers are working to plan and prepare their playground gardens for sunny warm days.  Here is one way to incorporate the scientific method into indoor seed starting (or planting pots) with kids.

The seeds at the preschool mentioned here were started Monday, March 31st so we are now in stage 2 of the seed-starting process where the sprouts go from starter mix into the smaller pots then back under the lights until the garden is ready outside.  Here’s the link to the blog that explains the seed starting process: http://www.growinggreenhearts.com/blog/, but you could also purchase small plants at your local garden center then transplant them into bigger pots.

Here’s a basic timeline:

  • Starts seeds in starter mix with lamps indoors when you’re craving sunshine and green grass the first week of April (late start this year?…plan to purchase 3rd week of April)
  • Transplant the seedlings three weeks later in celebration of Earth Day or Easter and measure their growth as they leaf out under the lights
  • Mid-may harden off the plants by gradually moving them outside a longer duration each day to adjust to temperatures and natural light
  • For Mother’s Day or after as temperatures allow, put them into your garden or larger pots

Excellent preschool teachers, as well as the NAEYC (National Association for the Education of Young Children) standards, put emphasis on learning process rather than just the final product.  Here’s how this activity with plants connects with the scientific method, science basics, cognitive development, and inquiry:

Step 1:  State the problem question

This time of year, most of the grocery store tomatoes are shipped to Minnesota from Florida and California.  Summer in Minnesota is too short for vegetable plants to produce a lot of stuff to eat!  Explore what the children know about the needs of living things by asking, “What could we do to help the plants grow vegetables faster?”  Opportunities to elaborate on energy from the sun, seasons, and spring changes are:  compare the amount of daylight by sharing sunrise and sunset times for April 21st, May 21st, June 21st, hike around to find signs of new life such as tulips coming up, greening grass, etc.  After student questions, guiding questions from the adults, comments, ideas, and a bit of research the problem question that you’ll eventually land on is:  How could we help the plants get bigger faster than they would outside here in April?

Step 2:  Make a hypothesis/smart guess based on knowledge

Plants need water, soil, air, light, space, and the right temperature.  Let’s give them what they need inside until the soil, air, and temperatures are right outside! Transplanting the seedlings now should help them along enough by mid to late May.  Books about plant life cycles and parts of plants are great support for this step.  A strong hypothesis uses if/then format:  If we give the plants what they need (water, soil, air, 16 hours of light, space, and temperatures warmer than 60 degrees) then the plants will grow taller each week. 

Step 3:  Test the hypothesis with an experiment

Here is where you show, share your plant experiment station and get your hands dirty by transplanting sprouts from starter mix to pots/4-pack containers with potting soil.  The plants will have light form the lamp, warmer temperatures inside, water will seep into the soil to the roots through the bottom of the trays, the soil contains food for the plants to grow bigger, and the new pots we plant in will provide the sprouts with the room they need to grow bigger.  More information on lamps, seed-starting, and planting basics can be found here: http://www.growinggreenhearts.com/blog/.  Get the students involved in the experiment station set-up with where to place the plants, how to label them, what tools to use them for measure.  A fair experiment also needs a control.  Place one plant that has been transplanted outside where it will not get it’s needs met by you.

Step 4:  Collect the data, make a graph, and look for patterns

Use a calendar and graph to show the days and plant heights.  Remind students that the evidence collecting will either support or not support the hypothesis/smart guess:  If we give the plants what they need (water, soil, air, 16 hours of light, space, and temperatures warmer than 60 degrees) then the plants will grow taller each week.  Another idea to talk about is, “What makes an experiment fair or unfair?”  An unfair experiment has too many variables and not a control that can be used for comparing.

Step 5:  Draw Conclusions:  Did my guess hold true or not hold true?

As the weeks pass, continue to ask:  Does our hypothesis/smart guess hold true or not hold true?  Conclusion: Yes, the indoor plant heights increased, so we the students are giving the plants all of the things they need.


Play. Learn. Love.

April 2014