When the air turns crisp and the sun starts to wane, the trees may be the first to notice that fall is in the air. Got little ones wondering why the leaves are turning colors and falling to the ground? Give them a quick science lesson about plants and they’ll soon be little horticultural pros. Don’t forget to add jumping in a big leaf pile to your autumn learning activities!
Take a walk outdoors in a natural setting where you and your youngsters can see bright fall colors and talk about the concept of autumn leaf color and drop.
Talk about the concept of summer solstice and autumn equinox with your tots to give them an oh-so-brief overview of the way the Earth works. On the first day of summer -- summer solstice -- the sun is the strongest and the day is the longest of the entire year. Slowly, the sun gets a little weaker and lower in the sky until the first day of autumn -- autumn equinox -- when daylight and darkness are divided exactly in half.
Make a point about the amount of light and warmth that disappears between summer solstice and autumn equinox so your youngsters get the picture. Between the first day of summer and the first day of autumn, the gradual decrease in light and warmth has a major effect on some kinds of trees.
Switch the focus to those majestic trees growing outside and talk about how trees work. Tell your little ones that trees make a special pigment (color) called chlorophyll that makes leaves green. Explain that when the sun shines long and strong down on plants and trees, they make lots of chlorophyll, which keeps leaves green.
Ask your kids if they have any guesses about what leaves turning color has to do with days getting shorter and the temperature getting cooler as time approaches autumn equinox. Hopefully, you’ll hear ideas about less sunlight causing trees to make less chlorophyll, which means that leaves won’t stay green. If your kids need a little steering in this direction, that’s okay.
Explain to your youngsters that as soon as trees stop making all that chlorophyll, other pigments take over and new colors begin to show through on the leaves. This is when leaves turn yellow, gold, red and brown instead of just being green.
Finish up the lesson by explaining why the leaves will eventually flutter to the ground. Tell your kiddos that a tree has strong roots, branches and twigs -- these parts are tough enough to stay healthy even during a cold and snowy winter. Leaves aren’t so tough, though -- they would freeze quickly and this might hurt the tree. So, the tree protects itself by dropping its fragile leaves and going to sleep during the winter. When the weather gets warm again, the tree wakes up and the whole cycle starts over again.