Dr. Christmas Tree is used to the question. He gets it all the time. What is the perfect Christmas tree?

Don’t expect him to name one kind of conifer. The answer varies depending on who’s buying. He usually answers the question with a question. How long do you want the tree to last?

Gary Chastagner leads the Christmas Tree Research program at the Washington State University Puyallup Research and Extension Center’s Ornamental Plant Pathology program. Throughout his four decades of research, the plant pathologist has studied needle retention, cut-tree care, disease management, variety improvement, and more. The goal: longer-lasting and healthier Christmas trees.

Gary Chastagner holds an evergreen tree branch
Gary Chastagner (Photo Randy Harris/Offset)

His latest work focuses on finding high-quality varieties with excellent needle retention and resistance to Phytophthora root rot, a fungal disease that limits where highly desirable species can grow in the United States.

The Pacific Northwest produces about a third of the country’s Christmas trees, including virtually all the noble fir. It has the potential to hold its needles and last for a long time post-harvest. But there’s limited, if any, Phytophthora root rot resistance within populations of noble and Fraser fir, another long-lasting variety that retains its needles well.

“We have identified several species of conifers, such as Nordmann and Turkish fir from areas around the Black Sea, which appear to be resistant to the Phytophthora in the Pacific Northwest,” says Chastagner, who⁠—along with researchers nationwide⁠—is finishing a 10-year study to determine regional adaptability of these species for use as Christmas trees in America. The work has taken him to Turkey and the Republic of Georgia for seed cone collection.

Chastagner, who recently won a Lifetime Achievement Award from the National Christmas Tree Association, has been looking for alternative species since the late 1980s after arriving in Puyallup in 1978. He began working on Christmas trees the following year, examining Swiss needle cast on Douglas fir⁠—which then made up some 90 percent of Christmas trees grown in the Pacific Northwest. Growers needed help managing the fungal disease, and the state legislature directed WSU to work on the problem.

“Within a couple of years, we had demonstrated that over 80 percent of the Douglas fir trees in Washington and Oregon were infected and that losses exceeded $3 million per year even though the premature loss of needles caused by this disease at the time of harvest only affected the marketability of a relatively small number of the infected trees,” Chastagner says.

His lab showed the presence of infection on trees whose marketability was not affected had a hidden impact; they dried faster and shed more needles when they were displayed post-harvest. His lab also showed that a single annual application of fungicide to new growth two or three years before harvest, costing five cents per tree, controlled Swiss needle cast.

“The treatment program we developed is still widely used today, not just here in the Pacific Northwest but elsewhere. Growers have basically been able to eliminate losses caused by this disease for almost 40 years now.”

That research led to his next project: studying how much moisture trees could lose between harvest and sale without being damaged. Identifying this threshold, coupled with studies on changes in moisture of trees throughout the supply chain, showed most drying occurred on retail lots.

Chastagner’s research took him throughout the United States for retail lot surveys. He conducted his first surveys in 1982, when most retailers displayed trees on wooden stands. “Utilizing information from our retail lot trials, now many retailers display trees in water and use overhead misting at night,” says Chastagner.

Three-foot Christmas trees are part of his checked baggage. He gives his grandchildren their own annual Christmas trees. “Each kid gets to decorate their own tree,” he says. “If my wife and I can’t visit, I put them in a tube and mail them. They get their trees one way or the other. But it’s more fun when we go and take them.”

Chastagner and his team maintain about 12 acres of Christmas trees. Their research has been supported by the Pacific Northwest Christmas Tree Association, the Real Christmas Tree Board, Washington State Department of Agriculture, US Department of Agriculture, and industry partners.

“Gary Chastagner has been the most influential person in my development as a Christmas tree farmer,” says Randy Rapetti, a choose-and-cut grower in Camino, California. He’s allowed Chastagner to establish a Nordmann fir demonstration planting on his farm and written letters of support for research proposals. “I am a better farmer, and a better person, because I know him.”

Kristi Scholz-O’Leary, president of the Pacific Northwest Christmas Tree Association, agrees. She and her parents, JoAnn (’68 Ed.) and Ken Scholz, who chairs the group’s Advanced Research Fund, run Orting’s Snowshoe Evergreen, a conifer nursery, choose-and-cut farm, and wholesaler that also houses one of Chastagner’s test plots.

“His work stretches far beyond the Pacific Northwest,” says Scholz-O’Leary, who chairs the association’s capital campaign, which, along with the Washington Nursery and Landscape Association, is raising funds to establish an endowed chair for continued research after Chastagner’s retirement. “We certainly would not be where we are today as an industry without Gary’s work. He’s not only a scientist and a researcher, but he is able to forge partnerships with other scientists and researchers. To me, he’s more than Dr. Christmas Tree. He’s a miracle worker.”

If you want your tree to last 7 to 10 days, pretty much any evergreen will do. But if you want to put your tree up at Thanksgiving and have it last into the new year, you’re going to want a noble or Fraser fir, or Nordmann or Turkish fir. “In some of our trials, we’ve been able to maintain some of these high-quality trees for two to three months,” Chastagner says. “But it depends on how both the retailer and the consumer take care of the tree.”

Wholesale growers tend to sell “very uniform” trees to retail lots. Choose-and-cut farms “cater to quirkiness or diversity or whatever it is a person is looking for. “Sometimes,” says Chastagner, “the perfect trees are Charlie Brown trees.”

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