By Mark Abrams

PHILADELPHIA (CBS) — A “baker’s dozen” of new trees are set to take root in Washington Square, in Philadelphia’s historic area.

Michael Dixon, facility manager of Independence National Historical Park, is supervising the planting of trees in the historic Washington Square area over the coming weeks.

Today, Dixon (below right) carefully directed the planting of a new sassafras tree and a river birch.  He says it’s only the beginning.

(Michael Dixon. Credit: Mark Abrams)

“We’re going with 13 entirely different varieties that presently, here at Washington Square, are from buckeyes to magnolias to sassafras,” he said.  “And those are the common names, not the scientific ones.”

Dixon, who clearly knows his trees, says he worked closely with a federal landscape architect to find the right varieties, and to “put something for all of the patrons that come to our park.  It’s something different to look at, and not only improves the aesthetics but the environment at the same time.”

Dixon says he takes his job seriously and respects the sacred ground which is entrusted to him.

“This used to be a potter’s field. Your first urban prison’s over there. The Revolutionary War buried thousands here, and every time we do an installment, an excavation, or a root grinding, we have to have an archeologist on site, by law.”