For 42 years, John Seiler was here for students. 

Describing himself as a “blue collar professor,” the man known as Dr. Dendro taught various classes in forestry, always with a zeal that was evident to the students.  

At the end of May 2026, Seiler closed his career as a professor at Virginia Tech, retiring with a long and distinguished career that impacted thousands of students. 

For Seiler, longevity wasn’t the centerpiece of his personal vita. He was known for how he related to students, how much he expected of them, how hard he worked and asked them to work, and how he wove personal style into his classes.  

Seiler’s time predates the 1992 establishment of the College of Natural Resources and Environment. Prior to its creation, the School of Forestry and Wildlife Resources was housed in the College of Agriculture, now the College of Agriculture and Life Sciences.

While he was a successful researcher who conducted many studies and advised dozens of graduate students, Seiler taught many undergraduate courses in the department now called Forest Resources and Environmental Conservation. He’s best known for teaching dendrology, a core course, for more than three decades, giving it the unusual duality of being routinely described by alumni as their hardest class and their favorite class.  

Dendrology taught lessons far beyond the characteristics of trees: it required dedication and tenacity because falling behind made attaining a high grade even more difficult, and the class was held outside, no matter the weather.

To those earning an A, Seiler presented a peppermint patty, which held a symbolic value far exceeding their worth. 

A native of Pittsburgh who proudly donned the black and yellow of the Steel City’s various sports teams, Seiler graduated from Penn State, then settled in Blacksburg to earn his doctorate. 

He looked back on his teaching career, his students, and the changes the university has experienced in his time on campus: 

When did you come to Virginia Tech?

I came here in the fall of 1981 as a graduate student. I finished my Ph.D. in the summer of 1984. Right at that point, my [advisor, Jon Johnson] left, and I got hired as a postdoc to pick up some projects that he left, immediately.  

In the meantime, they start announcing their new job. I applied for it and ended up getting a position here, which at the time was unusual.

I started as an assistant professor in January 1985, six months after I finished my Ph.D.  

I got [Johnson’s] old desk, his phone, his Rolodex. All the phone numbers. I literally just took right over from him and went right into his office.

How did Pittsburgh shape you?

I grew up in Pittsburgh, maybe four miles from downtown. Steel mills all over the place, the air stunk; the water was filthy. Now it's all cleaned up. They reinvented themselves. 

There was a work ethic that came from a place like that. It stays in your blood. 

I'm a blue-collar professor, not a not a white-collar professor. That work ethic stuck with me a lot.

Can you describe the School of Forestry and Wildlife Resources when you arrived?

It was smaller, but when I got here, there were already three departments: wood products, forestry, and fish and wildlife.  

John Hosner was the director, and the administrative structure was much smaller. 

One really big difference is the forestry department had very strong sections. I was in the forest biology section. We had a forest biometry section, a forest economics section, a forest recreation section. Those sections had section heads. When the department needed things, they'd tell the section heads. 

Everything from the annual report to advisory board meetings were organized by these sections, and then the sections were all in suites together. Forest biology was in Suite 228.

We had softball tournaments where every section had a softball team. Afterward Hosner had a picnic at his house. 

So how much classroom instruction versus research was there?

There was probably a little more teaching for everybody, maybe 20 percent more teaching. Everybody had classes all the time. I don't think you really had a semester off.  

I always kept a big research program, too. But I always had a really heavy teaching load. It’s just something I love to do.

One time, Dave Warcutt said he needed help teaching plant physiology, which was not even in our school. It was in another department in Ag. And I said, “I'll teach half of it with you.” I taught plant physiology down the hill for three years. 

I taught a class that had horticulture kids in it, and biology kids in it. Our kids weren't in it. When an opportunity to teach arose, I always went for it. 

I never understood when someone would ask about the teaching load, like it’s bad. I always would say: “It's going great. I just created a whole new class called Appalachian Forest Ecology, and now I've got two classes each semester at a minimum.” They start looking at you like you're from Mars.  

I've taught all kinds of weird stuff. I taught wildland fire. I had no practical experience in it at all, but there was nobody else in the section.

How did you come to teach Dendrology?

Pete Feret taught it. He passed away suddenly in 1993. Pete and I co-taught forest biology. I got dendrology and all of forest biology, too.  

When did the Dr. Dendro persona come around? 

I don't know exactly. It was pre-social media. John Peterson just started calling me Dr. Dendro. [Former department head] Janaki [Alavalapati] used to say it all the time, but that was because I was starting to become known as that. So, he'd say, “This is Dr. Dendro,” at Forestry society meetings or anywhere we met people.” 

How did the tradition of giving out peppermint patties start?

As a grad student, I was taking physical chemistry with Dr. Jim Wightman, a chemistry professor, who is an outstanding alumni distinguished professor. He was passing back the first exam, back when you handed back exams. And it's a pretty big class and me and a few other people scattered around didn’t get our exams. Then he says, “There's a small group in here that got A's on this exam.” He called us up and we all got a candy bar. I still remember, I got an O. Henry. I really thought that was special.  

I decided to do that, but I'm going to get peppermint patties because they look like a medal. Students really go after them.

The deal is you must have an A-minus or above at the last lab before the final. Students who raise their grade [into the A range] on the final can get the peppermint patty.  

I had them their sophomore year, but at some point, we started seeing a couple go across the stage during graduation. [Former Dean] Paul [Winistorfer] said, “What’s with these peppermint patties?” He knew it had something to do with me because they were showing me. He wasn’t annoyed, just puzzled. 

They're getting the peppermint patties when they're sophomores, and they're keeping them till they can wear them like a sash at graduation. 

I saw a student from 20 years ago and her husband was there. She told me they were cleaning out a home office and he found the peppermint patty and asked, “What's this thing?” She said, “You don't throw that out.” And she grabbed it. She had to explain what it was.

Is it strange that Dendrology is among the most popular classes while being one of the most difficult?

That's rare that the most popular and most difficult coincides like that. I just heard this story from somebody I didn't even recognize who had the class 25 years ago. She said, “That was the best class I ever took, and the hardest darn thing I ever took.” 

Every week, if it’s not an exam, we were right out the door -- a few announcements and then we just headed right out, no matter what the weather is. We were out there this year when we had the Arctic air for three weeks straight. And that goofy snow that had the ice underneath. They were out there in that. Unless Tech is canceled, we go, and I tell them that. It's pouring rain and someone asks, “Are we going?” Unless the campus is closed, we're going.

Dendrology is a lot of stuff to take in. Students are so used to waiting five weeks and then studying. Wait five weeks and study again. You can't do that. And it's the first time they've ever been hit with that. You have to always do a little.  

It's like music: you're sick for two weeks, you missed two piano lessons, except the problem is we can't go back. You're jumping into week four with everyone else. So, it's extremely hard. We even tell them at the end of the first lab, “Here's what you just had. The piano lesson. What do you have to do between piano lesson one and piano lesson two?” They say, “You have to practice.” I said, “If you don't practice, what happens?” They say the piano teacher knows. I said, “I'm gonna know.”

Have there been changes? Constants?

When you came to work for John Hosner, you came here because you knew you were coming to the best program. Everybody worked like you were working for the best program in the U.S.  

I came here knowing this was the best place, and John Hosner meant to keep it that way.  

Every year when the advisory board would come here, he'd put pressure on the administrators that we need to be our own college.  

I think we proved him correct. 

We might be the smallest, but per capita, it's a very aggressive, active college.  

There was this mindset of, if you made it here, it was one of the best places to make it. 

I see rankings that say we’re still pretty high. 

What's next? 

A lot of things. I have several ministry things that are church related. If there are things folks can't do, I do it for them. Like when they have a drippy faucet, they have a hole in their drywall; they need a shower handle put on. I was always saying, “I can't come this Saturday, but I'll come next Saturday.” Now I'm going to be able to say, “I'll come over this afternoon.” There's a woman who bought a bunch of flowers, but she can't plant them. I said, “I'll be over next week.” I'm looking forward to being able to say, “Hey, I'll be over there after lunch.” 

There are also some other things my wife already volunteers for that I’m going to sign up for and volunteer. 

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