FOCUS: After a plant flowers and produces fertile seeds, those seeds must still find a spot to grow. We’ll see what the inside of a seed looks like, how it holds all that is necessary for a new plant to grow, and explore outside to see the many different seeds we can find and the ways they move from place to place.
Objective: To begin to explore and ask questions about seeds.
Give a variety of seeds and seed heads to children to examine in small groups, and ask what similarities and differences they notice.
Materials: a variety of seeds and seed heads, magnifying lenses.
PUPPET SHOW “Travel Agents”
Objective: To obtain information about some of the seed dispersal strategies that are important in a plant’s life cycle.
Perform the puppet show, or have a group of children perform it for the class. Afterward, ask questions to review the key details and vocabulary in the story. What do we mean by “seed dispersal”? (Traveling.) Why do seeds travel? (To reach a suitable habitat free of competition from the parent.) Hold up the puppets one by one and ask how the character got around. Use the How Seeds Travel poster to show examples of the different ways that seeds disperse.
Materials: puppets, script, stage, props, brown pompom for burdock burr; How Seeds Travel poster.
Objective: To collect and observe a variety of seeds and seed heads outdoors, looking for evidence of seed dispersal strategies.
Have the children work in small groups and provide each with a paper bag for collecting seeds. With their groups, children will collect a variety of seeds from their schoolyard. Have each group try to collect only one example from each type of plant, leaving the rest for other classes. Challenge them to find as many different seed heads as they can.
Spread out a large white sheet that will serve as a place for the children to return to after they collect their seeds. When they are finished collecting, have them gather around the sheet and spread their seeds out for all to see. After everyone has admired the collection, ask some questions to guide the children to look more closely.
Ask questions about the seed head collection such as these:
- Which ones look like they might be hitchhikers? Why?
- Which look like they might be eaten by an animal? Why?
- Which ones look like they are made to travel by wind? Why?
- Which ones came from trees?
- Which ones were flowers?
- Which ones have the most seeds in them?
- Which ones (if any) have just one seed?
Finally, have everyone pick a seed or seed head to disperse.
Materials: paper bags for collecting seeds (one per small group), Seed Safari sheet, clipboards, pencils, magnifying lenses, large white sheet or shower curtain.
UPPER GRADES CHALLENGE: Seeds Up Close (Grades 5-6)
Objective: To observe closely the structure of a seed head or seed case and its seeds and to make detailed drawings of each.
Bring students to a place where they can find and collect a seed head or seed case to study and draw, or provide a selection of seed cases that you collect ahead of time. Some common weeds to look for along roadsides are Queen Anne’s lace, curly dock, campion, wild cucumber vines, or milkweed. Cultivated flowers such as poppies, lupines, irises, mallow roses, and sunflowers have interesting seed cases that are easy to find in the fall. Have students examine the outside of the seed case first and then carefully open it up to see how the seeds are carried. Ask them to draw the unopened or opened seed case showing the seeds inside on the Seed Sketch sheets. How are the seeds released?
Have each student remove a seed from their seed case and examine it with a magnifying lens or under a microscope to see the finer details of the seed coat. Encourage them to include these details in a drawing of the seed. What evidence do they see of how their seed might travel?
Materials: Seed heads or seed pods from wild or cultivated plants, clipboards, pencils, magnifying lenses and/or microscopes, Seed Sketch sheets; optional: field guides to wildflowers or weeds in winter.
MILKWEED SEED MIX-UP
Objective: To use a model to see that the conditions where a seed lands will determine whether it can sprout and grow.
Beforehand, make enough copies of the Milkweed Seed Mix-up cards so that there is one for every child. Use the numbers in parentheses in the Materials list as a guide to create a set of cards. Be sure to have more favorable conditions than hazards. Fold these cards and put them into a hat or basket.
Explain to the children that they will be playing a running game in which they might be a milkweed seed, a condition favorable for germination, or a hazard for the seed, depending on the card they draw. Designate four bases in an open area. Have each child draw a card from the basket to discover which role they will be playing in the game, and remind them to keep their role a secret.
At “go,” the children will run around the bases in the same direction. When you call out “stop,” they must run to the nearest base and stay there. When everyone has stopped moving, ask the children with milkweed seed cards to raise their hands.
The object of the game is to see which of the milkweed seeds lands in a place with enough favorable conditions so it can sprout and grow. Have the children who landed on the same base as a milkweed seed reveal their roles. Remember, the milkweed seed can only successfully germinate if it has more favorable conditions than hazards. Together, determine which, if any, of the seeds were able to sprout. Point out that whether a seed could sprout or not was simply a matter of chance. Why do plants make so many seeds? (Only a small percentage will ever reach a place where they can grow.)
Before playing a new game, have the children return the cards to the basket. Reshuffle them and have everyone draw a new card.
Materials: Milkweed Seed Mix-up cards, one per child, including Favorable Conditions: good soil (4-6), sunlight (4-6), water (4-6); Hazards: drought (1-2), hungry insects (1-2); Milkweed seed (1-2); four gym cones for bases.
SCATTER TO THE FOUR WINDS
Objective: To model how wind carries and scatters milkweed seeds through the air.
Gather the children on one end of an open space with the wind at their backs. Hand out a single milkweed seed with its downy plume to each child. Identify a landmark that will be the final destination. Challenge the children to blow or fan their milkweed seed to move it through the air from start to finish, without touching the seed with their hands. If their seed reaches the destination, it will be able to sprout and grow into a new milkweed plant! Be sure to dry out milkweed pods overnight to make the seeds fluffier. Set this activity up in a hallway or gym if the conditions outside are too windy or wet.
Materials: milkweed seeds (at least one per child).
SEED LOOK and JOURNAL ACTIVITY
Objective: To observe a lima bean through dissection and identify the parts that allow it to grow into a new plant.
Ahead of time, prepare lima beans for the children to dissect. Dried beans should be soaked overnight. Frozen beans can be left at room temperature for a few hours to defrost. Have children work in small groups at tables, benches, or on a tarpaulin. Provide each child with a napkin, magnifying lens, lima bean, pencil, and paper or science journal. Have the children examine the beans with their lenses, looking at the seed coat. Ask them to describe the seed coat and help them find the hilum, where the bean attaches to the inside of the pod. Have them draw a picture of the bean in their journals. If possible, show them some dried pods to illustrate how the beans are attached. Now ask them to remove the seed coat and set it aside.
Have them carefully separate the cotyledons to expose the embryo, the tiny new plant inside. Use the Parts of a Lima Bean diagram to help them identify the beginnings of the root (radicle), stem (hypocotyl), and leaves (plumule). Now have them make a second drawing to show the inside of the lima bean. Optional: Use a water-soluble marker to stain the embryo.
For older children: Provide other beans for the children to dissect so they can observe and compare the seed parts. Fava beans, kidney beans, chickpeas, or any other large bean will do.
Optional: At least a week ahead, put some beans between damp paper towels to sprout them. Pass around for children to see the growing plants.
Materials: dried lima beans or other large beans (one per child) soaked overnight, Parts of a Lima Bean diagram and Lima Bean Information sheet, magnifying lenses, journals or paper, pencils, napkins or paper towels; optional: tarpaulin, water-soluble markers, assortment of bean pods, assortment of large beans, presoaked.
SEED SHOWCASE AND FRUIT SNACK
Objective: To observe and compare the arrangement of seeds inside a variety of fruits while enjoying a refreshing snack.
Bring along an assortment of fruits that contain interesting seed patterns, such as apple, strawberry, kiwi, pomegranate, or grapes (with seeds), optional: vegetables like green pepper, cherry tomatoes. Cut open the fruit to expose the arrangement of seeds and compare. Slice, serve, and enjoy!
Materials: assortment of fruit, serving plates, napkins, knife for slicing, small cutting board.
Objective: To review and share thoughts about seed dispersal strategies.
Ask the children to complete this sentence, “If I were a seed, I would travel by ____________.”
A STEP BEYOND
How Many Pods? Locate several milkweed plants that have gone to seed. Have the children compare and contrast the two plants by counting the pods and the seeds inside each pod. Ask the children what similarities and differences they notice between the two milkweed plants.
Banana Research: Have the children find out why bananas don’t seem to have any seeds.
Unique Seed: Have the children invent a seed with a totally unique method of dispersal. Be creative!