(Radio Iowa) – If you were to try counting all of the trees on the University of Iowa campus on this Earth Day (Monday), you’d need to be able to count to eight-thousand. The man who leads the team that cares for them all realizes he’s one of the lucky people who’s found the perfect job for himself. U-I arborist Andy Dahl says he’s been planting and caring for trees since he was five years old. “I used to pick up acorns and put them in my pocket and plant them all over, or mow around the baby oak trees coming up in my parents’ yard,” Dahl says, laughing. “My dad would get so angry that I was leaving those, missing big swaths of grass to let the trees grow, so yeah, my love of trees started at an early age.”

The U-I has been named a Tree Campus USA for the 15th straight year, in large part because of those eight-thousand trees which cover an astounding 350 different species.  “I’m big into diversity, so the more species of trees you have, the less chance you have of something like Dutch elm disease or emerald ash borer coming in and wiping out wide swaths of trees,” Dahl says, “so we try and plant a wide diversity of trees to avoid that.” The list of trees on the Iowa City campus includes an apple tree that was grafted from one planted by Johnny Appleseed, and a horse chestnut tree grown from the one that symbolized hope for Anne Frank as she hid from the Nazis during World War Two. One of Dahl’s campus favorites is the giant American elm on the Pentacrest, just outside Schaeffer Hall.

“It’s a former state champion and it dates back to the 1870s,” Dahl says. “It is very, very large. Now in 1998, we lost about 30 feet of height in it from the straight line winds, but it’s still hanging on. I think it’s beautiful. Others think it has character with the scars over the years from the storms.” That’s the only tree on campus that’s being treated chemically in order to prevent the scourge of Dutch elm disease. Several campus tree plantings are planned as part of Earth Day celebrations, while Dahl and some co-workers will be on the Pentacrest at 10:30 A-M, handing out 100 whorled milkweed plants to students and anyone else.

“We’re going to give them away in little cups, so people can grow them on their windowsill until later,” Dahl says, “or they can do what we call guerrilla planting: if you see a spot in the ditch, on a railroad track or something, you can plant that to benefit these native pollinators.” He says the whorled milkweed species will grow to two or three feet in height with white flowers. It’s native to Iowa and is vital for insects like bees and butterflies, especially monarchs.