BLACKSBURG — This fall is setting up to please leaf peepers.
“What’s cool about Virginia is we have such high diversity of tree species,” John Seiler, a professor in forest biology at Virginia Tech and an expert on autumn foliage, said while walking through Stadium Woods on campus this week.
The state’s forests offer better colors “than we’ve ever been given credit for,” he says.
“I say it’s even better than New England.”
Seiler predicts Oct. 24 and Oct. 31 as prime weekends to catch a rich array of yellow, orange and red leaves throughout the region, though continuing cold weather could speed up that time table.
A good amount of rainfall this year, particularly in September, will make for a vibrant display, which is caused by a mix of environmental and genetic factors. Drought causes leaves to turn early and fall sooner, and the red pigments in some leaves don’t develop as well.
Bright, clear days this month will be critical to produce the red in leaves, since intense sunlight activates sugar compounds that cause the color, Seiler said.
Tech’s fall foliage expert cautioned to avoid judging the season based on urban trees. Such trees are often under water stress, which means leaves turn and fall off earlier, and the original seed doesn’t necessarily come from the region.
The coronavirus pandemic has forced Seiler’s tree identification class fully online, while another is in-person and a third in a hybrid mode.
While Seiler hopes to do more in-person classes this spring, Tech has the benefit of having what he calls the “biggest collection of digital plant material,” with upwards of 26,000 photos.
Seiler is also one of the brains behind VTree, a smartphone app used across the country to identify foliage. The phone’s GPS narrows down species of foliage where you’re standing and has short questions to help pinpoint the type of tree you’re seeing.
For those who may still be stumped, the app allows users to send photos to “Dr. Dendro” — as in dendrology, the study of trees — for further clarification.
And Dendro would be Seiler, of course. Every morning, he wakes up to about five to 10 emails from people hoping he can tell them what kind of tree they’ve encountered, he said.
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Trees like this dogwood are not stagnant. As the days get shorter and the temperatures get cooler, leaves will change from green to red and from green to yellow and orange.
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Virginia Tech forestry professor John Seiler uses Stadium Woods on campus as an urban forest classroom. Some of the white oak trees in the woods are over 360 years old, he says.
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Certain leaves on a black gum tree may change color before others depending on genetics, the environment and the amount of sun it receives.
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A sugar maple tree is in the process of changing colors on the Virginia Tech campus. The tops of trees often turn color sooner due to sunlight exposure.
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Virginia Tech forestry professor John Seiler, a.k.a. Dr. Dendro, is a tree expert and a developer of the Virginia Tech tree identification app.
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Black gum leaves exposed to intense sunlight often turn red, whereas the shaded part of the same leaf may not change at all.
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Seiler
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Black gum trees often turn maroon and orange in autumn, making it a popular tree on the Virginia Tech campus.
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Virginia Tech forestry professor John Seiler answers questions from the public on the school's tree identification app.
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Virginia Tech forestry professor John Seiler looks at a dogwood tree that is in the process of changing color. Leaves change color as the tree extracts fluids and nutrients from the leaves.