Discuss different facts about leaves....

A leaf is a part of a plant.
Leaves are found on flowers, trees, bushes, and other types of plants.
Veins in leaves carry water within the leaf.
The leaf stalk holds the leaf toward the light.
Leaves carry food to plants.
Water travels from the tree roots up to the leaves through tiny tubes in the trunk.

Collect a variety of leaves and bring them into the classroom.
  Make leaf patterns for each child.  Place the collected leaves on a low table
 for the children to examine.  The children can observe whether the leaves feel rough
 or smooth, whether or not the leaves have a smell, whether the veins are visible,
and if there are stalks on the leaves.  Acknowledge all answers as valid. 
Have children color the different shaped leaves on the patterns. 

The Magic Formula

Explain to the children that some leaves change color in the fall, and ask if any of the
 children has ever seen red, orange, or yellow leaves.  Discuss the fact that only certain
 trees have leaves that change color and drop.  These are called "deciduous" trees.  Have
 the children slowly repeat the word deciduous.  Teach children the formula
 that turns leaves different colors:

Chlorophyll makes green leaves bright.
They stay that way from warm sunlight.
But in the fall there is less sun.
The leaves turn color, one by one.
They change to red, then gold, then brown,
Then they fall down onto the ground.
But in the spring, just wait and see,
All new green leaves will fill the tree.

Introduce Hibernation

Primarily with bears and squirrels.

What happens when a leaf loses chlorophyll?

Collect green leaves and place them on a tray to dry.... over time
they turn brown without chlorophyll the leaf loses his green color.

Fall Harvest Sensory Tub

(Photo submitted by Shell)

Place several items that are harvested in the Fall into a large tub.
Place the tub in your science area for the children to explore the different Fall items.