When should we expect the fall colors on the trees this year?
BOWLING GREEN, Ky. – Autumn seems to have fully settled in here in south-central Kentucky.
The fall temps are a very welcoming sight after what seems to have been a very hot summer. But while the fall has arrived, some are now asking where’s the colorful trees and leaves?
Well, when the colors pop, that is dictated by a chemical called chlorophyll, which helps trees produce food and keeps the leaves green. When the cooler temps start to roll in, those chemicals start to fade, turning those leaves those pretty colors.
“When fall rolls around, the environment signals to plants that it’s time to get ready for a winter and so chlorophyll kind of goes away,” said Martin Stone, a professor of horticulture at Western Kentucky University. “The plant doesn’t replace the chlorophyll, during this time of year, and the oranges and yellows kind of persist longer in the leaf. And so they suddenly it feels like they suddenly appear. But really, they’ve been there the whole year.”
It is a balancing act, however, as colder temperatures could lead to frost and even freezes that can quickly kill leaves, and any hopes of those long lasting colors that we all love.
“Whenever we have a frost, it forms ice crystals and it messes with the cell structure in those leaves. Leaves are what the plants use to make food. It’s the green, the chlorophyll makes food when it interacts with the sunlight. So this time of year we have less sunlight. They’re able to make less food. And that’s the reason that we see this change in color start. And for those trees or those plants that don’t change color, well, that’s when they start to kind of wither for the season. And so the frost messes with that more by damaging those cells even more,” said News 40 Meteorologist Scott Burchett.
For south-central Kentucky, the first frost usually occurs sometime around Halloween, leaving not much time left for those colors to come out and stick.
But that first frost date is not definitive, and could move a later into the season, creating even more time for the leaves to change their color.
“We know when the average frosts are at the beginning of the season, the last frost and then the first frost in the fall, but that can fluctuate two weeks in either direction. So each season is individual. We can talk in generalities about average dates, but any given season it can fluctuate seven, ten, 14 days in any direction,” Stone said.
With the cooler temps now here and that average first frost date quickly approaching, the question now remains is there any hope for those gorgeous colors this year?
“There is hope for us to have a good looking fall. Like I say, we are late. But if you look around at the leaves in town, here in Bowling Green and in our area, they’re generally still bright green, which means that they’re not yet ready to change. We can just hope that the freeze is delayed and we have this beautiful, clear, sunny days and cool nights. And eventually, hopefully, they will turn and give us the show that we’re we’re looking for,” said Stone.
