Palms

I heard that leaves change color in Fall due to less sunlight hitting them, signaling the trees to stop creating chlorophyll, allowing the carotenoids to show through, making the leaves look reddish-orange.

But if this were completely true, then why don’t leaves change color in the Summer if you live in a place where it is really cloudy, thereby simulating, in terms of the amount of light hitting the leaves, that it is Fall?

It is not so much the amount of sunlight as the length of daylight. As the days get shorter the day length eventually reaches a trigger point and the leaves stop producing chlorophyll, allowing the underlying colors to show up. Good question, though.

Posted leaves |