It’s officially pumpkin spice season, and that’s worth celebrating. It likely comes as no surprise to our readers, that the arrival of Fall means new fall colours for our trees. Some even lose their leaves altogether… But why? How can this annual phenomenon be explained?
Some botanical facts
First and foremost, trees need lots of sunlight in order to flourish. Essentially, they transform light from the sun into energy and nutrients through a phenomenon known as photosynthesis. Chlorophyll which can be found in their leaves, is what gives trees their green colour, and needs lots of sunlight to function optimally.
As you know, during the Fall season, days shorten, and the amount of sunlight we see in 24 hours decreases. In order to survive, the tree enters a state of rest and gradually slows down its functioning in preparation for winter. When photosynthesis slows down, chlorophyll abandons the tree’s leaves and instead heads to the trunk, leaving the beautiful colours of Autumn in its place. As the temperature continues to get cooler, sap begins to circulate throughout the tree, leaves dry out, and subsequently begin to fall.
Nothing is lost! Once the leaves have hit the ground, they create a barrier that protects the tree’s roots against frost and conserves humidity levels. As they decompose, the leaves enrich the soil and contribute to the nourishment of the tree’s roots.
The only exception to this rule is coniferous trees, such as pines or firs. Why? Unlike leaves, coniferous trees are ordained with needles that have a layer of wax around them that protects them from the cold throughout the Winter season. However, some varieties such as larch, bald cypress and metasequoia can lose their needles every year or two.
The Magnificent Fall Colours
Yellow/Orange: The green colour of the chlorophyll slowly fades to reveal other pigments present in the leaf: carotene, which is orange, and xanthophyll, which is yellow, creating magnificent shades of colour.
Red: Anthocyanins: Some trees produce anthocyanins that allow them to ward off insect pests and protect themselves from the sun’s rays thanks to its antioxidant properties.
In any case, you can always put your trust in our team to take care of your trees all year round.