By Eric Sorensen, WSU News

It’s that time of year for Gary Chastagner, variously known as Mr. Christmas Tree, Dr. Christmas Tree, Dr. Gary and even Scientific Santa Claus. He was fresh off trips to Arizona and Anchorage, Alaska, where he had been looking over Christmas tree lots, and paused on an unseasonably warm day at the Puyallup Research and Extension Center to share the latest in his field of nearly 40 years.

A plant pathologist, Chastagner is one of the world’s leading experts in the care, feeding, selection and display of Christmas trees in both the field and the living room. His thoughts on falling needles and the best stand for holding your tree have graced the pages of The New York Times, the Los Angeles Times and the Wall Street Journal.

He’s fresh off the largest Christmas tree research project in U.S. history, a $1.3 million effort funded by the U.S. Department of Agriculture National Institute of Food and Agriculture to find genetic markers for resistance to Phytophthora root rot and for improved needle retention. The work could help both growers, who can lose 75 percent of a crop to root rot, and consumers who hate vacuuming.

At 69, he appears to be in no hurry to retire. He is enjoying life in the field and out among the market stands, clipping branches for analysis and chatting up vendors.

“While some of my family was out shopping on Black Friday, I was visiting retail lots, looking at trees and collecting samples,” he said. “We’re trying to get information on the quality, particularly as it relates to the moisture status, of trees that are largely grown here in the Pacific Northwest and shipped into other market areas.”

His large research project, which is wrapping up, confirmed that noble and Fraser firs are particularly susceptible to Phytophthora root rot, while Canaan fir is less so and Nordmann and Turkish firs, under the right conditions, were quite resistant to the disease.

Meanwhile, the Collaborative Fir Germplasm Evaluation Project, or CoFirGE, is still looking at the genetic materials in a seed collection drawn from around the world, including trees from northern and western Turkey, where Chastagner and other scientists went collecting in 2010. The work, which involves more than a dozen universities and industry groups, aims to find superior trees from several varieties.

“That’s really going to benefit the Christmas tree industry by keying in on some species and alternatives that might help them manage Phytophthora root rot,” Chastagner said.

A close up of a green Christmas tree branch being held by Gary Chastagner
Chastagner inspects the branch of a Christmas tree

As it is, it’s something of a Christmas miracle that a tree performs well at all once severed from its roots and transported hundreds of miles. Anchorage trees are shipped in by barge from the Lower 48, where the stock is much fuller than the local Charlie Brown trees. On a recent visit, Chastagner saw retailers taking good care of their product, keeping them out of the cold and moist enough to retain their moisture.

“When customers take those trees home, if they properly care for the tree, they’re going to have a really good experience with minimal problems,” Chastagner said. “That’s very different than in Tucson, or a very warm market. They were having record high temperatures Thanksgiving weekend in the Tucson area. It’s really difficult to keep the trees fresh.”

Even without a root system, a Christmas tree is in a sense alive, or at least “physiologically, biologically active.” It still draws water, transpiring it out the pore-like stomates on the undersides of its needles. With enough water—and the key feature of his preferred tree stand is a huge water reservoir—Chastagner has seen a cut tree last as many as three months. Some will have buds come out.

“The new growth will start to come out on these trees,” Chastagner said. “It can’t sustain itself but the tree from a physiology standpoint is still behaving very much like is was still attached to its roots.”

Chastagner had yet to pick a tree when we spoke, but he was leaning to a noble fir, with plenty to choose from among the retired stock on the research center’s 15 planted acres. Sometimes he’ll get a particularly large tree, trim the branches off the lower three feet, and put it in a deep hole outside the house.

“I drop the base in that hole and I have an instant Christmas tree right in front of our picture window,” he said. “Sometimes my wife gets a little frustrated because it’s still up in March. You have no problems with it drying out. There’s no needle-loss issues or anything like this. And yet you still have a Christmas tree.”