MARY LOUISE KELLY, HOST:

North Carolina is a leading producer of Christmas trees, and the Cadillac of trees is their native Fraser fir. It is, though, an evergreen under siege. Paul Garber from member station WFDD reports on the threats to these holiday favorites and the scientists who are trying to save them.

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PAUL GARBER, BYLINE: A light snow is falling on Waightstill Avery’s Christmas tree farm along the North Toe River. But the scene is hardly festive. The river overflowed when the remnants of Hurricane Helene swept through in September. Even trees six feet tall were completely submerged. The ones left standing are covered in silt, making them unsellable.

WAIGHTSTILL AVERY: It’s a mess. In all this field, everything you see from here to the green grass will have to be dozed. There’ll be a foot of soil taken off the top.

GARBER: Avery says he lost about 60,000 trees. Some were ready for market. Others were just taking root. Surveying the crop before the storm, he was optimistic.

AVERY: You just thought, OK, this is going to be a good season, and here’s what we’re going to make happen. And in one night, it’s not going to happen.

GARBER: Long before Helene hit some tree growers here, the race was on to save Fraser firs from a variety of threats they face - warmer winters, pest infestations and the biggest threat of all - a spreading root rot called Phytophthora, Latin for plant destroyer. It’s similar to the blight that caused the potato famine in Ireland.

JUSTIN WHITEHILL: We’re really digging into the question of what happens when the Phytophthora starts to infect Fraser fir.

GARBER: That’s Justin Whitehill, who runs a Christmas tree genetics program at North Carolina State University in Raleigh. He and his team are reading the DNA of Fraser firs to find out how best to protect them, and beating the root rot is job No.1. It’s a challenge because once the rot hits, it’s almost impossible to get out of the ground.

WHITEHILL: The pathogen can survive in soil for, we know, at least 20 years because we’ve had abandoned farms and land that folks have gone back to and tried to replant, and as soon as they replant, the disease pops up again.

GARBER: If there are Fraser firs and Christmases yet to come, Tracy Taylor’s work may play a key role.

TRACY TAYLOR: North Carolina has developed the best Fraser fir genetics in the world, and they’re in this field right here beside us.

GARBER: Taylor is superintendent of the Upper Mountain Research Station in Ashe County. He runs a seed orchard of young trees culled from the 25 hardiest, most resilient Fraser firs scientists could identify through genetics. In a few years, seeds from these trees will be sent to Whitehill’s lab in Raleigh. They’ll be analyzed for ways to grow Fraser firs that are able to withstand the threats. Fraser firs grow naturally in foggy Appalachian mountaintops 5,000 feet high. But that’s not how they grow commercially, says Taylor.

TAYLOR: In the field we’re standing in, we’re probably standing about 3,100, 3,200 feet. So we’re already bringing those trees down in elevation, which is a form of stress. Then some of these other factors we deal with, like root rot, drought, insects, heat - anything that comes along, you know, the stress starts to compound and makes it more and more challenging.

GARBER: So what makes a Fraser fir special anyway? Taylor said it’s got everything consumers like - the perfect shape, the denseness of its branches, the needles that cling to the tree longer than most others and, of course, that holiday aroma.

TAYLOR: We say it smells like Christmas. People like the way it makes their house smell when they put a Fraser fir in their living room.

GARBER: The race to save the trees is not just about saving an important piece of the holidays. Fraser firs form the backbone of the agricultural economy in this mountain region. For NPR News, I’m Paul Garber in Ashe County, North Carolina.

(SOUNDBITE OF LONDON CHAMBER ORCHESTRA’S “O’TANNENBAUM”) Transcript provided by NPR, Copyright NPR.