"It's been a strange year -- I think the trees are a little confused," said Mary Kroening, University of Missouri extension horticulturist.
Apparently, it's the periodic fall-like weather the state's been having this summer that's confusing the trees. The cool, sunny weather mirrors that which typically occurs in September and October -- a time when trees begin storing their food for winter and changing color.
Horticulturist Chris Starbuck with the University of Missouri pointed out normally the coloration process starts with shorter days -- which is why the pigmentation process usually starts in early October. Bright, sunny days are ideal for fall color, and often times plants of all kinds will turn because it helps them to conserve their sugars they make in the day through photosynthesis, he said.
"If the weather stays warm, and sultry, it burns all of its sugars at night and isn't available to produce pigments, but if they get a lot of photosynthesis in the day, then they conserve their food at night and produce pigments," Starbuck said.
Fall leaf color is produced when the plants stop making chlorophyll, which makes the green color in leaves, Kroening explained. So when it's turned off, green is no longer a dominant color and the other colors are likely to become more pronounced as the tree readies for winter dormancy, she said.
"A lot of the red and yellow pigments are there all summer, but we don't see them because the green chlorophyll is dominant in the plant," Kroening said.
Some trees beginning to turn color across the state already include black gums, dogwoods, sumacs, maples and bradford pears.
"It's been such a wonderful, cool wet summer," Kroening said. "Typically, if trees are drought-stressed, their ability to show fall color is reduced. But they're in great shape, not over wet not over dry -- assuming we stay the same way."
Starbuck has worked in Missouri for the last 25 years and has never seen a summer like this one, he said.
"This is kind of unusual," Starbuck said. "Sometimes when trees are stressed, generally in drought conditions, this happens. But we're certainly not experiencing a drought -- it's much cooler than average weather."
Once the colors do begin to burst into fall mode, A.J. Hendershott, supervisor for outreach and education division for the Missouri Department of Conservation, urges families to check out the scenery.
"Just getting out and doing it as a family activity is the best way to see the color -- and walk it, don't drive it," Hendershott suggested.
Hendershott said visiting anyplace that has a lot of trees such as the Mingo National Wildlife Refuge, Big Oak Tree State Park or just below the Benton hills and Crowley Ridge.
"Colors are always going to change, the question is are they going to be good," Hendershott pointed out.
And it's upcoming weather that will determine how bright the fall color is this year, Starbuck noted. Peak fall color in Missouri is usually mid-October.
Meanwhile, rain with temperature highs in the high 80s and lows in the high 60s are predicted for this week, according to the National Weather Service.
"It's hard to predict what might happen," Starbuck said. "If it turns 100 degrees, it might mess things up a bit."