The Seed Dispersal Project is a great fall activity for elementary students who live in the northern states.
First, teach students about the different way seeds can be scattered, or dispersed in an environment.
Some are be moved by the wind (maple seeds, dandelion seeds). Some float and can be moved by water (apples, coconuts). Some move by sticking to animal fur (burrs, thistles, etc.). Some are eaten by other animals, digested, and dropped out the other end (berries, fruits, etc).
Tell students they are responsible for collecting seeds that are spread in different ways. You can have them collect seeds spread by wind, water, animals, etc.
They can mount the seeds on a posterboard, label the names of the seeds, and tell how they are spread.
Kids can learn about seed dispersal with a hands-on approach, and these projects look great hanging up in the hallway of the school.