May Moment of Science:

April showers bring May flowers.  This old quote (originally attributed to Thomas Tusser in 1557) is often quoted in the spring and is a nice reminder about the importance of water for the growth of all plants.  This moment of science will help you to explore the anatomy of a plant by examining a seed.  Then, we will encourage you to plant a seed, give it all the necessary ingredients (including water) for it to grow, and watch as it grows into a beautiful flowering plant or delicious and nutritious food for you to eat. First, gather your materials:

  • Raw lima bean
  • Small container (cup, bowl, Tupperware, etc.)
  • Tap water
  • Seed appropriate for planting based on the time of year (see list, below)
  • Clear, plastic cup
  • Scissors
  • Soil (nutrient rich soil is best)

Then, follow these instructions:

  1. Start by placing your raw lima bean into the small container.
  2. Cover the bean with enough water so it is fully submerged.
  3. Wait about 10-15 minutes, until the bean is beginning to wrinkle, but is not completely soaked through.
  4. Carefully break open the lima bean along the natural seam.
  5. This young plant has been dormant (inactive) and will remain that way until the conditions are optimal for the plant to grow. For most seeds, they need water to be introduced into their environment to bring them out of dormancy.  Some of our native plants in California need to be scarred or even burned in order to begin growing.  Let’s examine the parts of the seed.  (See diagram below.)  *Note: some lima beans have larger examples of the epicotyl and hypocotyl than others.  Larger beans often will have larger, easier to see examples.lima bean
    1. Epicotyl: looks like small leaves; forms the leaves of the plant
    2. Seed Coat: protects the seed; keeps the young plant from growing until the conditions are optimal
    3. Cotyledon: provides initial food for the young plant; the main part of the seed itself
    4. Hypocotyl: forms the stem of the plant
    5. Radicle: forms the roots of the plant
  6. Once you have learned the parts of a seed, it is nice to be able to watch the seed begin to grow into a plant.
  7. Choose a seed or two (see list below).
  8. Use the scissors to poke a few holes in the bottom of the clear, plastic cup for drainage.
  9. Fill the cup with soil (it does not need to be filled to the top).
  10. Plant the seeds along the perimeter of the cup so you can see the seed from the outside of the cup.
  11. Pour a little water onto the top of the soil.
  12. Watch your plant grow! You should be able to see the leaves and stem begin to emerge from the seed and even see the roots begin to grow.  Make sure you keep the soil moist, but not soaked, with water so your plant can keep growing.
  13. Once your plant is big enough, you can transfer it into the ground or a larger container by carefully taking it out of the cup, along with all the soil, and planting all of it together in the new location. Continue watering as you watch it grow.

Seeds that are great to plant in May:

  • Marigolds
  • Sunflower
  • Zinnia
  • Corn
  • Beans
  • Pumpkin
  • Squash
  • Cucumbers
  • Melons

Plants need soil, water, sun, and air to grow.  Their roots hold them firmly in place in the soil and they also allow the plant to gather the water and other elements they need to make their food.  The food itself is made inside the leaves of the plant.  The water is picked up by the roots and moves up the stem to the leaves, where it is combined with the air.  Part of the air moves into the plant through holes in the plant’s leaves.  Using the light from the sun, the water and air in the leaves are changed into sugar, which the plant uses for food.