Why do leaves change colour?
Why are leaves green?
In the spring and summer trees have green leaves. A chemical called Chlorophyll gives the leaves their green colour.
Leaves make Cholorophyll to use to make make food for the tree. The leaves need lots of sunlight to make Cholorphyll.
When the days become shorter and colder at the beginning of Autumn the leaves stops making Cholorphyll.
So why do leaves change colour in autumn?
When Autumn arrives the trees prepare to go to sleep for the winter. The leaves now use up any food they have stored away.
Because the leaf has stopped making the Cholorophyll that made it green you can now see the yellow, orange and red colours of the leaf – which were hidden by the green!
At the beginning of Autumn you’ll only be able to spot a few yellow and orange leaves. As the weeks go by most leaves will change colour.
Why not take a photo of the trees near you at the beginning of Autumn and again a few weeks later to see the change!
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Why do leaves fall in autumn?
As the leaf uses up it’s stored sugars (food) a layer of corky cells form at the bottom of each leaf near it’s stalk shutting the leaf off from the tree.
As the corky cells shut the leaf off from the tree sugars build up in the leaf turning it from yellow and orange to red .
The leaf has done it’s job and will now fall from the tree. When the leaf has died it will become brown and will feel crunchy in your hand.
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Autumn Activity Ideas
Go for a woodland walk
Go for a walk in a woodland near you. It’s fun playing in the leaves as they fall. Have a look and see how many different coloured leaves you can find. Look at the shapes of the leaves. Watch them as they fall from the trees. And have fun!
Make a leaf picture
Collect different coloured leaves and make a picture with them. The five flamingo’s have made an owl! All you need is some leaves, glue and paper.
Make a bird feeder
Encourage birds to visit your garden by hanging up a seed bird feeder. Once you have hung your bird feeder you can sit and watch all the different birds as they visit your garden.