Minnesota trees on track to produce bright colors this fall
This could be a great year for fall color in much of Minnesota.
Thanks to a healthy dose of rain, most of the state is neither abnormally dry nor in drought - a good sign for those hoping for bright yellows, oranges and reds in the trees.
"For right now, we're on track to have a great fall color year," said Val Cervenka, forest health program coordinator for the Minnesota Department of Natural Resources.
While decreasing daylight largely drives the timing of fall color, hydrology and weather conditions can affect its intensity. Drought, for example, can mute what would otherwise be bright colors.
As of Sept. 1, there was no drought in the state and the only area considered abnormally dry was a pocket along the North Shore, according to the U.S. Drought Monitor. The dry conditions near Lake Superior might have an effect on the leaves, but not if there are significant rains over the next few weeks.
"They could get a lot of moisture and that could increase the color by the end of the season," Cervenka said.
Along with rain, temperature can play a role in color intensity.
"Warm sunny days, followed by cool, but not freezing, nights are what will give us the best color," Cervenka said. "And this is still pretty darn early for that. We're still going to get the warm sunny days, but we're nowhere near the really cool nights we need."
It's also too early to tell for sure what fall color will be, as the weather over the next few weeks could end up negatively affecting the colors.
"It can change, if say, all of a sudden we didn't get rain for a month," Cervenka said. "It's kind of localized, too."
A hard freeze would also have an effect, causing leaves to fall. On the other hand, a light frost could help intensify color, said Cervenka, calling it "a fine line."
It's unclear exactly when peak fall color will hit various parts of Minnesota, but it usually begins along the Canadian border in mid- to late-September and ends in southeastern Minnesota in early to mid-October, according to the DNR.
The Twin Cities metro usually sees peak color in late September to mid-October.
Some leaves can be spotted already changing, but those colors are coming prematurely due to dryness and other stressors.
The color changes normally come when a tree determines that it's time to shut down for winter.
Chlorophyll, a key ingredient of photosynthesis, is continually breaking down in leaves, but in the fall, the chlorophyll stops getting replaced and the green pigments its responsible for disappear, revealing the yellows, oranges and reds made by other biochemicals.
One way to check fall color conditions is through the DNR's fall color map, found at dnr.state.mn.us/fall_colors/index.html.
The map is continually updated with fall color reports from Minnesota's state parks. As of Friday, only two parks - Bear Head Lake State Park in northeastern Minnesota and Camden State Park in southwestern Minnesota - were reporting fall colors.