This activity is excerpted from GrowLab: Activities for Growing Minds, a K-8 curriculum developed by the National Gardening Association. To learn more about this and other educational resources, visit our online Gardening with Kids store.

Go Seeds Go!

Overview: Students explore various seed dispersal adaptations and invent their own creative modifications to disperse seeds.

Time:

• Groundwork - 1 to 2 40-minute sessions
• Exploration - 45 minutes
• Making Connections - ongoing

Materials:

beans or other large seeds
6-inch pots
Seeds: Pop, Stick, Glide
miscellaneous materials-cotton, feathers, wool, toothpicks, rubber bands, springs, pipe cleaners, lemon juice, balloons, yarn, crepe paper, etc. 
egg cartons (optional)

Advance Preparation: Soak fifteen to thirty bean seeds overnight. 

Laying the Groundwork

Objective: To discover many of the ways seeds travel.

1. Discuss whether students think seeds have the ability to move from one place to another. Ask, for instance: Do you suppose people plant a lawn full of dandelions? How might the ability to move help a seed? How do you think they move? What examples have you observed in nature?

2. Read the book Seeds: Pop, Stick, Glide with the class.

3. If time and your location allow, take students on a fall "traveling seed" walk. Observe mature plants. Look at the ground, water, the air, and animals in search of clues that suggest how seeds might travel. Collect some seeds to bring back to the classroom.

Back in the classroom, check socks and pant legs for seeds that might have "hitchhiked" with you. Have students observe their seeds and try to guess how each might be dispersed. (Also include some pictures of seeds.) Students can use egg cartons to sort seeds, with each cell containing seeds dispersed in a similar way. Consider having students glue seeds on a bulletin board, sorting them by the way they’re dispersed.

4. Discuss and make a list of adaptations that seem to enable seeds to disperse in different ways. For example:

5. Share with students that when looking at a seed, we can’t always tell what its dispersal method is. In many cases, for instance, the fruit plays the key part, by luring animals that eat and them excrete seeds. In other cases, tension builds up as fruits dry (eg., in Impatiens and touch-me-nots), causing the fruit to explode violently and expel the seeds.

Exploration

Objective: To demonstrate understanding of seed dispersal adaptations by inventing creative travel mechanisms for seeds.

1. Challenge small teams to invent a strategy for dispersing some type of garden seed (or fruit). For instance, create one that . . .

• hitchhikes on your wool sweater or on an animal for 10 feet.
  
• attracts a bird; the seed passes through the bird’s acidic digestive tract and back to the soil. (Hint: Consider using acidic lemon juice in the simulation.)
  
• is thrown 5 feet from the plant by a special mechanism.
  
• is carried on the wind for at least 4 feet.
  
• floats downstream and is washed up on shore.
  
• (use your own ideas)

2. Supply students with the miscellaneous materials listed above. These materials should be used to modify seeds to help them reach a 6-inch pot. Bean seeds that have been soaked overnight will be the easiest to work with. Have teams first discuss their design, draw sketches, and decide on one design.

3. Once teams have had a chance to test and modify their designs, have a Go Seeds Go! Event. Invite each team, in turn, to demonstrate its seed dispersal mechanism. Have the team members first tell a short story to highlight the nature of the trip taken by their seed, explaining the natural conditions they simulated. Give each team three tries, allowing members to modify the setup, if necessary, in order to reach the pot. 

Making Connections

Possible discussion questions:

• What portion of the dispersed classroom seeds actually reached a pot in which they would have been able to grow? How does this compare to seeds in real life? Why do you think many plants (eg., dandelions) produce such a large quantity of seeds? (This strategy ensures that at least some will survive and produce new plants.)
  
• What do you think would happen if seeds did not travel away from parents? Imagine a tree dropping all of its seeds directly underneath. How might that affect the ability of each seed to thrive and grow?
  
• How do you think real-life conditions would be different from the simulations?
  
• How did the contribution of each member of your team help in the design of your invention?
  
• If you were a seed, what method of travel would you choose? Why? What do you think would be the pros and cons of that "lifestyle"? 

  Branching Out

• When taking a walk in a meadow or overgrown field, wear old socks over your shoes. Back in the classroom, use a hand lens to examine the seeds that have "hitchhiked" on the socks. "Grow" the socks.
  
• Charles Darwin once took a clump of soil from the leg of a dead partridge, watered it, and observed eighty-two different plants emerge. Suggest your students repeat Darwin’s experiment, scraping off and "planting" mud from their boots or from their dog’s paws. You and your pets are pretty efficient seed dispersers!
  
• Bring in a dandelion or other plant about to disperse its seeds. Have students calculate the number of offspring that one plant would produce if all seeds found new homes and survived.
  
• Research how the seeds of different fruits in your indoor or outdoor garden are naturally dispersed.
  
• "Become a seed,"  by acting out a certain dispersal method. Ask classmates to guess what type of dispersal adaptations the depicted seed has.
  
• Write creative travel stories from the perspective of a seed that has left its parent with the help of a natural force.
  
• Find pictures to compare seeds to human-made objects, (eg., maple seeds and helicopters or burdocks and velcro).

   Extension: People Moving Seeds

  Discuss with students the many ways in which people may aid in seed dispersal. Ask: What do you do with your apple or watermelon seeds when you’re through? Share that immigrants to this country purposely brought seeds from their own countries to plant, and accidentally brought additional seeds, in bales of hay, straw, or on articles of clothing. Exploring the origins of some of our common food crops can provide insights into humans' role in moving seeds. Tomatoes and peppers, for instance, are native to South America; cucumbers hail from India; watermelon comes from Africa; and oranges and grapefruits originated in China.