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What Makes Autumn's Colour?

October 8th 2014
By: Melanie

Throughout the Spring and Summer leaves make the food for plants and trees. Plants take in water up through their roots and carbon dioxide from the air, they use sunlight through a process called photosynthesis to turn this water and carbon dioxide into oxygen and glucose. Plants use glucose as energy and a building block for growing. To be able to do photosynthesis the plants need a chemical called chlorophyll, and its chlorophyll that gives leaves in particular their green colour.

As the days get shorter and shorter deciduous trees know winter is coming and during the winter there is not usually enough light for photosynthesis so trees go into a state of rest, and live off the food they have stored during the summer. As they shut down the green chlorophyll disappears from the leaves and they become more yellow, orange and brown in colour, small amounts of these colours have been in the leaves all through the year but covered up by the green in chlorophyll.

The bright reds and purples we see in leaves in Autumn derives from glucose trapped in inside after photosynthesis has stopped. Further sunlight and the cool nights of autumn can cause these leaves to turn this glucose into a red colour. Maples are some of the trees that can be most affected in this way that's what makes your Japanese maples, such a wonderful display of colour at the end of the summer, nearly time to look out for your best local wood in Essex and Herts for Autumnal colour.