The late summer drought is causing some trees to show their autumn colors early, but the annual foliage show is only just beginning.
Hank Stelzer, a forestry extension specialist at MU’s College of Agriculture, Food and Natural Resources , said adequate moisture throughout summer and bright light, warm days and cool nights in the fall are ideal for fall colors.
The late drought caused yellows and browns to emerge early in the leaves of some trees, but shades of red and purple are still on the way.
“The pigments that are responsible for the yellows and browns we see in the fall are actually in the leaves throughout the growing season,” Stelzer said. “We just don’t see them because they are hidden by the green pigment in the leaves. As the growing season comes to a close, the green pigment breaks down allowing the yellows and browns to show through.”
Stelzer added: “The reason we are seeing some yellows now is due to the lack of rainfall these past few weeks.”
Stelzer said the reds and purples we see in the fall are the result of pigments being produced during September and early October in trees rich in anthocyanins, such as white oaks, maples, ashes, sassafras and sumac.
Sassafras, sumac and Virginia creeper are among the first to change color in mid-September, according to the MDC Fall Color Report. Black gum, bittersweet and dogwood begin to change around late September.
“I’ve noticed some ash trees changing already,” Ann Koenig, a forester at the Missouri Department of Conservation, said. Stelzer said he has predominantly seen hickories starting to show color.
Ashes, maples, oaks and hickories normally don’t reach the height of their display until the overall color peak, which should be the second or third week of October, Stelzer said.
Although there shouldn’t be any diseases causing problems for the foliage this year, Japanese beetles are “another issue totally,” Stelzer said.
“People might notice fewer trees with fall color because Japanese beetles hit some species of trees pretty hard,” Koenig said.
“They’ve decimated some trees in our cities and towns,” Stelzer said. “We don’t see them across the wooded landscape.”
Trees that are personally owned and being fertilized are more at risk of being affected because the beetles go after the nutrient-rich foliage in the fertilizer, Stelzer said.
Stelzer recommends the Katy Trail State Park from Boonville to Hermann for those looking for the best views of fall color in central Missouri. Tram tours will be offered on the trail again this season from Rocheport to McBaine.