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Lesson 1: Seeds and Germination Needs

To prepare, read Background Information

Objectives
 Students will:

  • Learn how plants produce seeds
  • Explore the different parts of a seed
  • Discover germination and seed needs
  • Observe the growth of a seed into a seedling

Central Concepts:

  • The germination process
  • Proper seed planting procedures

Standards addressed: click here

Materials:

  • Seed packets
  • Clean plastic water bottles with tops cut off
    (Note: Cutting plastic can be tricky and should be done by adults ahead of time.)
  • Moistened soilless potting mix
  • Dark colored construction paper

Discussion Questions

1. Why do plants produce seeds? (To reproduce their species)

2. How are seeds produced? (Via the process of pollination)

3. What are the parts of a seed? (Seed coat, endosperm, and embryo)

4. What do seeds need to grow? (Moisture, warmth, air) What is germination? (When a seed "wakes up" from dormancy and sprouts.) What keeps seeds from sprouting inside their packets at the store? (Seeds are dormant until they have all the conditions they need to sprout -- moisture, warmth, and air).


In-Class Activity: Seed Planting Depth Experiment

1. Introduce students to how seeds are created and the parts of a seed. Create a chart or model to illustrate. Here are some images to guide you:
Parts of a Flower
Parts of a Seed
For a hands-on model, soak dry lima beans (available grocery stores) overnight and give each child several lima beans to open and explore. This is a very simple dissection, and even very young students can easily find and identify all the parts of a seed.

2. Discuss the conditions that seeds need to grow. Ask students to read the instructions on the back of sample seed packets and list the factors they need to consider when preparing to sow seeds.

3. Give each child a clean plastic water bottle with the top removed. Fill the bottles with moist soilless mix to about an inch below the lip. Instruct students to plant seeds around the inside surface of the plastic bottles at different depths. You can use any type of seed you have on hand. At minimum, plant one at the bottom of the container, one at the suggested planting depth (listed on seed packet; or use the rule of thumb of 1½ to 2 times the width of the seed), and lay one on the surface of the soil. If you have enough seeds, students can plant them at varying depths.

4. Make a construction paper sleeve for the bottle to block light from the seeds. (Light is a variable in the germination process of some plant species, so by creating a sleeve you are limiting the variables.) Students can extend the experiment by covering some bottles and leaving others exposed to the light.

5. Monitor germination and record observations. Note the date that germination occurs and measure the growth of the seedlings. Discuss findings and ask students to write conclusions about proper seed planting depth.

6. Follow up with a data-sharing session. Ask students: Did seeds germinate at all planting depths? Did they make it to the top of the soil? Did they sprout at all depths? Why or why not? (Deeply planted seeds use up the stored energy in the endosperm before their sprouts reach the surface; or seeds needs aren't met at those deeper levels, and they don't sprout.)

Extensions:

Math -- Keep track of the number of seeds that germinate in the experiment above. Determine germination rates and discuss how to display the findings as fractions and as percentages. Translate the findings into different types of charts and graphs.

Language Arts -- Create a seed journal to track the development of the seeds in the Seed Planting Depth experiment. Give students time each day to log their observations. Encourage creative writing at any time in the process.

History, Social Sciences, and Geography -- Check out the NGA article titled “History of Seeds that Feed” available on page 2 of Seeds Feed The World and use the activities suggested there. Or, assign students to research the origins of their favorite seed. Have them map the paths the seeds took throughout the world from their region of origin.

Health -- Explore the nutritional content of different seeds that we commonly eat (e.g., sunflower, sesame, pumpkin, peanuts, corn). Point out that many seeds are considered a protein source and explain why protein is so important to us. You'll find helpful background information in Seeds Feed the World

 

Copyright© 2005 National Gardening Association