He's checking it twice, Hub

Ross Pentz is Christmas Tree Extension Specialist at Nova Scotia's Department of Natural Resources. Which means he is the guy in charge of finding the giant spruce sent to Boston each year for our city's big holiday tree lighting ceremony. (Globe Staff Photo / Scott LaPierre)

WEST DUBLIN, Nova Scotia - It might not be on your mind right now, but your Christmas is just about all Ross Pentz can think about these days.

Pentz is the Christmas tree extension specialist at Nova Scotia's Department of Natural Resources. That means he is the guy in charge of finding the giant spruce that becomes Boston's official Christmas tree each year.

Heavy is the burden. Not many trees survive snow, wind, and bugs for the 50 years it takes to reach 50 feet. And even if they do, few are sufficiently lush and upside-down-ice-cream-cone-like to make the cut.

And though Nova Scotia ships 1.5 million Christmas trees to the United States, Bermuda, Panama, and Japan each November, Boston's official tree cannot be found among the vast, blue-green swaths of balsam firs that blanket the region's foggy coast. A really big tree has to have room to spread, so Pentz usually spots them standing alone, ornamental centerpieces of backyards or church grounds.

So the sinewy 53-year-old, a third-generation tree grower himself, is always searching. Always.

"It kind of gets in your blood," he says.

Sometimes he'll spot the perfect Boston Tree on vacation outside his province. These trees tantalize him.

"I'll think, 'Darn, I wish I had that tree in Nova Scotia,' " he says.

Sometimes he'll see a tree on the way to work or the beach, its tip peaking out over a rooftop. Sometimes it won't be quite big enough, so he'll watch it for a few years, hoping it lasts.

The tradition of the tree gift, begun in 1971, has its roots in the Halifax Explosion of 1917. Near the end of World War I, a pair of ships collided in Halifax Harbor, detonating a huge explosives cargo and killing nearly 2,000 people. Boston rushed doctors and supplies into leveled Halifax neighborhoods.

Even after all these years, Nova Scotians are still grateful, so grateful that owners who might not have dreamed of cutting down the big spruce Grandpa planted will gladly part with it when Pentz knocks on their door and asks if they would consider letting him put it on his short list for Boston.

"Oh, yes, people do consider it a great honor," Pentz says. "They say, 'Oh, my God, how can I refuse?' "

News crews swarm when the Boston Tree is trussed up, felled, and loaded onto the truck each November. Hundreds of schoolchildren come to witness the spectacle, cheering loudly when the saw whinnies, and the behemoth comes down.

Pentz holds his breath on the big day.

"Last year I had a fright," he recalls, pressing a palm to his forehead. "I was afraid they were going to break the top off the tree, which would have been a disaster. Ah, yes, it scared me so."

This year Pentz has several contenders. But because summer can bring storms, disease, and regrets, he'll wait until the latest possible moment, usually September, to name a winner.

One of the finalists, a majestic spruce, sits on a rise behind a construction worker's modest yellow house near the LaHave River on Nova Scotia's southern shore. This tree is perfect: Enormously tall, impossibly lush, completely symmetrical, its branches spread wide in the mist like welcoming arms.

A downpour begins as Pentz rushes out of the car to snap a picture one recent day. He has been watching this one for several years. When he came knocking a few months ago, he says, the owner was honored that his tree was being considered for Boston. But Pentz won't reveal the man's name.

"They're very disappointed sometimes, if the selection gets made and it's not their tree," he says.

When Mayor Thomas M. Menino lights the tree on Boston Common this Dec. 4, many of us probably won't be thinking of earnest Ross Pentz and the grateful people of Nova Scotia.

But Pentz and the others will be thinking of us.

Yvonne Abraham is a Globe columnist. She can be reached at Abraham@globe.com.