This natural phenomenon occurs when the chlorophyll in the leaves breaks down. As the green color disappears, the yellowish colors (masked by green during the summer) become visible and give the leaves part of their fall splendor.
Other chemical changes also take place in the leaves and cause the formation of additional pigments that vary from yellow to red to blue. Some of these pigments cause the reddish and purple colors in the leaves while others give the brilliant orange and fiery reds to the trees. The brownish and bronze colors are caused by the mixing of varying amounts of the pigments in the leaf in autumn.
Warm days & cool nights
Warm, sunny days, followed by cool nights, with the temperatures below 45 degrees F. are most favorable for the formation of the brilliant red autumn coloring. During the warm days, much sugar is produced in the leaves but the cool nights prevent it from moving from these leaves. The trapped sugars cause the formation of the red pigment which you see in the maple, dogwood, red oak, sweetgum, sassafras, and others.
The amount of color may vary from tree to tree because of each one's direct exposure to the sun. It even may vary on the same tree, for different exposures will cause different colored leaves. Autumn is a colorful season when we can enjoy spectacular scenery across the countryside.
As we watch the colored leaves in autumn, we often wish their brilliant colors would last longer, that we could save some to brighten up the winter. Why not try a few of the following methods of preserving these leaves and lengthening your enjoyment of them.
Children like to make leaf pictures with crayons. Place a leaf so the vein side is up. Put a sheet of thin paper over it. Hold the paper very firmly so the leaf doesn't move. With a crayon, color the paper over the leaf. Use rather slanting strokes or the side of the crayon. The leaf will begin to show up on the paper.
Then when you've formed the whole leaf, cut it out. It can be glued onto heavy paper to make note cards or leaf pictures.
To press leaves for using in crafts or a collection, gather them while they are still supple, not dried and brittle. Then make a leaf press. It can be a very simple one. Arrange your leaves between thick layers of blotters or absorbent cardboard. You also can use newspapers. Don't let the layers of leaves overlap or they won't dry well.
Place your stack of leaves in blotters between two heavy, flat boards, pieces of plywood, or heavy books. Bind them together tightly with cord or straps. These leaves should be stored in a dry, warm place for about 10 days. Check them frequently and tighten the straps as needed. With a tightly bound press, your leaves will stay flat.
Leaves under contact paper
You can display your pressed leaves under clear contact paper or plastic, either for making a picture arrangement or as a collection. You need to use two pieces of clear contact paper or plastic of the same size.
Plan the arrangement of your leaves. Then peel the backing off the paper/plastic, handling it only at the edge so finger marks won't show. Place the leaves into position on this paper. Remove the backing from the second piece and smooth into place over the leaves. Be careful you don't wrinkle the paper. Work from one end and smooth the paper/plastic carefully.
Enhancement with construction paper
These leaf pictures can be made, too, by placing your leaves on a piece or white or pastel construction paper. Then cover the front and back with clear contact/plastic adhesive sheets. Such pictures can be framed and hung.
These are just a few of the ways you can extend your enjoyment of leaves beyond autumn. With imagination and a search through craft books or websites, you should come up with more ideas.
More fall craft fun
3 Fall crafts for kids
Easy, cheap fall crafts
Fun fall crafts: Leaf prints