Tag Archives: beans

Our School Garden Grows

Posted on by rhondacarrier

Students spent a few minutes on Thursday observing their beans and doing some weeding. Our beans are looking good. The beans in the photo were planted 3 weeks ago and are green and healthy.  In the rows on either side, students saw that the seeds they planted a week ago were germinating and pushing through the soil to the surface. Since we had just talked about roots, stems and leaves in the classroom, it was fun to put that into immediate practice. I told them to pull the weeds up by the roots. They were amazed at the differences in the root structure of various plants and the depth of roots compared to the number of leaves and heights of the plants.

We’ve had a weekend of steady rain since the photo was taken. I wonder how the garden will look tomorrow?

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Needed: Light and Water

Posted on by rhondacarrier

We did the following experiment in class:

  1. Place 10 seeds in a pot with soil. Cover the seed. Repeat for 3 other pots.
  2. Label the pots 1, 2, 3, 4.
  3. Water pots 3 and 4.
  4. Place pots 1 and 3 in the light.
  5. Place pots 2 and 4 in the dark.
  6. Observe for 10 days

The purpose of the experiment was to help students understand that light and water are needed for growth of a healthy plant. The need for light was easy to see. Although the plant in sunlight with water (see image below) was long and spindly, it turned green, developed leaves and lived longer than the other plants. The plants in the dark stayed white, withered and died.

The surprise to all of us was how many of the seeds germinated in the dry pots – as many as germinated in the pots with water. In fact the seeds in the dark cabinet germinated best of all. The pots in the dark were in a cupboard under a sink. We determined that the pipes had water condensed on the sides, so there was more moisture in the air than we realized, and of course the classroom air in Florida in the summer is humid – with so much moisture that the seeds had a very good environment for germination.

The experiment lead to a discussion about the fact that different seeds have different requirements. We’ll come back to the idea later when we discuss ecosystems.

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Bean Seed Germination Photos

Posted on by rhondacarrier

Students were amazed at how fragile the embryo was and how easily it fell out when the cotyledons were separated. Students summarized what they knew about requirements for seed germination. We also discussed why it was important to correctly and gently handle the germinating seeds and the seedlings. Students also wondered if the seeds would still germinate and grow if the embryo was separated from the cotyledons. Some came back to revisit this question when they developed their seed germination experiments a few classes later.

Classroom note: Iodine + starch produces a blue-black color and is used as an indicator for the presence of starch. Many bean seeds contain protein, so not all bean seeds will pick up the iodine stain. The blue-black color highlights the embryo, and makes it easier to distinguish the embryo from the cotyledon.

bean embryo

bean embryo