A 45-foot-tall Colorado blue spruce dangled from a crane high above its longtime home on Brentwood Street in Portland as a police officer herded a group of onlookers into a nearby yard. Once across the street, their eyes and iPhones fixed on the swinging trunk.

“It’s really cool,” said 7-year-old Leila Watson, whose family gathered at a neighbor’s house for hot chocolate Thursday morning before watching the soon-to-be city Christmas tree get lifted up and lowered onto a trailer.

Every year, the city chooses a tree from a yard in greater Portland to turn into the centerpiece of its holiday decorations. This year’s tree grew for more than 50 years beside the home now owned by David Little and Mikki Jones-Little. It will be lit with some 4,000 lights in a ceremony next Friday and reside in Monument Square throughout the holiday season.

City Arborist Jeff Tarling, who said he’s “always looking” for the next city Christmas tree, considered a couple trees in Westbrook before determining they were too small. Another in a backyard in Scarborough would have been too hard to access, he said, and there were others in Portland, but the owners weren’t quite ready.

That’s when he turned to the Brentwood Street couple, who had lived in the home since 1990 and had been considering donating the tree to the city for a while.

“It’s time,” Jones-Little said Thursday.

The tree, which they watched grow from the height of their second floor to above their roof, had shaded out most of their small side yard, including a garden planted by Jones-Little, a landscape designer. Sensitive to the moisture in Maine air, the tree had started to shed its needles and was on its way to losing them all.

The couple probably would have had it cut down in a year or two. By donating it to the city, they said, they’re avoiding that cost and giving the tree a new purpose.

“It’ll be immortalized,” Jones-Little said.

About 30 friends and neighbors of the couple gathered on sidewalks near the tree Thursday morning. A chainsaw began to buzz just before 9 a.m. and, within minutes, the tree was lifted above cable lines in front of the house and laid onto a nearby trailer.

Amid a caravan of city trucks and police cruisers, the tree departed from the Deering Center neighborhood, barely making it a block before its branches got snagged on telephone wires – a repeated occurrence along its hour-long, 3-mile journey to Monument Square.

The sight of the slow-moving spruce, which at times took up both lanes of the road, stopped joggers and bikers in their tracks to take a look or a picture. Along the route, people came out of their homes and got out of their cars, held up by the caravan, to watch the tree lumber down the street.

A man in a hard hat and neon vest, armed with a long pole to unhook the branches, walked alongside the tree, as it plowed into traffic signals and whacked a limb of another tree on the side of the road.

When it reached Monument Square, police blocked off a section of Congress Street so it could be lowered into its new home and adjusted until it stood straight.

The tree was originally planted by the late William Richardson, who sold the Brentwood Street house to its current owners.

Ginnie Pelletier, the daughter of Richardson and his wife Freida, said she was “so thrilled” when she saw a television report Thursday morning that it had been chosen as the city Christmas tree. She rushed over to Brentwood Street to see it come down.

Pelletier, 57, moved into the house with her parents when she was a year old. She doesn’t know why or exactly when her father planted the tree, but it was part of the yard that she played in as long as she can recall.

“I remember when it was the size of a normal Christmas tree,” she said.

Her mother, who died in April, thought the tree might go up in Monument Square last year.

That it was chosen this year, Pelletier believes, is a sign from her mom, just saying, “Merry Christmas.”