WGNO

Shorter days, not cooler temperatures responsible for early change in leaf color

(KTVE/KARD) Have you noticed that the leaves may have a little bit of a tinge of Fall in them? That’s because they’re already starting to change.

Some smaller trees and plants… such as Sumac… Black Gum and Walnut… have already embraced spirit of Fall a little early this year, turning bright shades of red, orange and gold. But the chill in the air is not necessarily behind the change in color.


“What’s happening is the number of daylight hours is decreasing” says Kerry Hefner, Horticulturalist with Louisiana Agricultural Center.

This then triggers a series of chemical reactions within the leaf.

“Chlorophyll essentially stops, it will gradually slow down and then stop. And then, molecules called accessory pigments that generally are there either throughout the season or they are produced at some point during the summer and then unveiled as chlorophyll goes away” Hefner said.

With this being said, chilly temperatures do have a hand in how nice the leaves will end up looking.

“Cooler temperatures might help to intensify the colors ” Hefner said.

In addition to how much water is in the tree, the minerals in the soil and the overall health of the plant. It also affects when they fall, as they need a sharp cold snap to trigger the detachment of the leaf.