Seed Dispersal

How do Seeds Travel?

There are 5 basic ways for seeds to travel:

Wind
Maple, elm, dandelion, and cottonwood seeds all can be carried by the wind. These seeds have wings or other hair-like structures. The dandelion often produces lots of seeds to make sure that some get to places where they will germinate. Some plants like the burr have barbs that get caught in animal fur.
Animals
Animals carry seeds in their fur/feathers and in their digestive tracts. Some animals like squirrels bury seeds for a later date but then do not return for the seeds.
Water
Coconuts travel on the ocean by floating. Other seeds attach to logs or soil and float away. Some large and small seeds float.
Humans
People intentionally plant seeds in new areas.
Mechanical Means
Some fruits dry out and eventually become so dry that they explode or shoot out their seeds.

Activities

• Read books that tell about seed movement/dispersal. For example: The Tiny Seed by Eric Carle 

• Have children put an old pair of socks over their shoes and go for a walk around a park, garden, or the schoolyard. Back in class, have the kids examine the socks to see if any (and what kind of) seeds are stuck on their socks.

• Have children drop seeds/bulbs into small plastic cups/bowls of water to see if they sink or float.

recycled plastic egg carton container - sunflower seeds and bulbs float, bean seeds did not float

• Have children observe various seeds (maple, dandelion, etc.) with a hand lens then drop the seeds and observe how they fall. Record the seeds' movement.

• Wind Dispersal Experiment:  Give students a few different types of seeds. Have them observe the seeds with a hand lens and predict and record which seed they think would travel the farthest on a windy day. Talk to the students about safety issues around an electric or battery operated fan (keeping their fingers a safe distance from the fan.). Wearing safety goggles, have students drop seeds one at a time in front of a fan placed on the floor on low speed. All seeds need to be dropped from the exact same location. Have students observe the seeds being dropped and measure the distance each seed traveled. Students should record their data. A graph of the data could also be made.

some clipart by www.graphicsfactory.com