The odor in the breeze is unmistakable. Either someone’s thrown a thousand Yankee candles in a bonfire or —

“You can kind of smell it from here,” says Jim Rainey, sliding silver sunglasses up his nose, exiting his office in the solid waste management and traffic engineering building, walking deeper into the industrial grounds of the Arlington County trade center off Interstate 395.

And there it is. The heap. The tree heap. Three-thousand seventy-nine Christmas trees. An orgy of conifers, piled high and wide.

Where did Christmas go?

Part of it went here. Trundled in from the curbs of Arlington County.

A strand of tangled tinsel wriggles on a snapped branch. A red bow is stuck on the crown of a tree atop the pile. A single ornament, silver and dodecahedral, peers from behind a trunk near the ground.

They forgot me, it says.

Or, rather: Shhh. I’m not going back to that attic.

Few things go from God to gutter faster than the Christmas tree. First it grows for about seven years on one of the United States’ 15,000 Christmas tree farms among 350 million of its brethren. Then, for a matter of weeks, it is the touchstone of home and hearth, the canopy for the baby Jesus, the holder of very specific memories — like Aunt Jan’s ceramic angel-harpist ornament that’s always a little too heavy for even the sturdiest branch (and that’s why it reminds you of her).

Then it’s Christmas, and New Year’s, and the tree starts to look a little wan, a little out of place — like a scarf in summer — and the love is gone.

First, the denuding, then the curbing.

Fraser firs, forsaken. Balsam pines, spurned. Sad.

“Yes, but at least they’re not being burned or thrown in a landfill,” says Rainey, citizen services supervisor for the county’s Department of Environmental Services.

The Arlington tree heap will soon be heaved into a tub grinder and pulverized into goldish-green mulch — each tree yields five to 10 cubic yards of mulch — that homeowners will use to landscape their yards and nurture their gardens. Winter becomes spring, circle of life, “The Giving Tree,” et cetera.

But for the next week, the sad carcasses of curbed Christmas trees wait for deliverance. They roll off curbs into traffic, catch trash, look pathetic, prompt uncomfortable parent-child explanations. Last year, a little more than 9,000 trees came in from Arlington County. The District gathered about 102 tons of holiday trees. Prince George’s County collected 78 tons of Tannenbaum, which were shredded in Upper Marlboro for the annual mulch giveaway.

The waste-management fleets take your trees away. Sometimes they are perplexed: Nine- or 10-footers outside squat, single-story homes, for example, or a discarded tree standing upright, still screwed into its stand, still decorated and twirled with lights, as if its owner wanted to dispose of Christmas 2010 in its entirety. They’ve seen it all.

The White House’s towering 181/2-foot Douglas fir from Lehighton, Pa., came down early last week but was not laid sideways on Pennsylvania Avenue for pickup. The National Park Service retrieved it and will grind it to mulch for its parks (relax, it all goes back to the taxpayers in wood-chip form).

Across the river, four more-modest trees lean against four single-car garages underneath four red-brick townhomes in the Shirlington Crest subdivision in Arlington on Thursday afternoon. None of them belongs to Michael Shaw, who is the only person on the block to answer the door.

He has nothing to say about the Tannenbaums out back. The Shaws have an artificial tree.

“My wife and I both prefer a real tree, but it’s just one of those things,” says Shaw, 39, an equities trader. “Without even asking, my wife’s brother mailed us this 80-pound box. I think he got it from Frontgate, or one of those magazines.”

Box it up, and back to the closet. Or out to the curb, where the trees lie like homicide victims. Adult conifer, 5-foot-8, found on its side, its top pointing southwest toward the setting sun along 14th Street SE in Anacostia. Midsection crushed (blunt door-frame trauma?), trunk sap-spattered, needles bleached gray by a couple of days spent outside. Found on its person: a jumbo Honey Bun wrapper and a flattened 20-ounce bottle of Rock Creek Fruit Punch.

There are obese pines shoved into wrought-iron tree boxes on the sidewalk on New Jersey Avenue NW. In Capitol Hill, there are Charlie Brown-ish firs wedged upright between evergreen-colored garbage cans — a last hospicelike, dignity-preserving gesture on behalf of the homeowner.

Of course, there are those who love the tree too much, who keep the tree up for an unseemly length of time because they can’t let go of the Christmas spirit. Or because they don’t want to acknowledge the new year. Or because they are lazy (these are the people who still have a pumpkin on their front stoop).

Or because they’re convinced they can replant the tree outside.

“I have people e-mailing every year in February, saying their tree is picking up water and putting out growth,” says Rick Dungey, public relations manager for the National Christmas Tree Association, on the phone from Chesterfield, Mo. “And they ask, ‘Can I replant it? Will it grow a new root system?’ ”

Dungey laughs for a good eight seconds.

“The answer is no,” he continues, soberly. “The plant has stored energy within its tissue and basically what’s happened is the plant’s come out of its . . . dormant state because it’s been exposed to the light and warmth of the house. In other words, the tree thinks it’s spring.”

The dying tree thinks it’s being reborn? Sad.

“Human beings have been doing things like this to express their emotions for thousands of years — using a product of nature to feel more alive, to feel connected,” Dungey counters. “How is that a bad thing?”

Guess it’s not. But as you pass a curbed tree next week, give it a nod. You may be in its presence again, perhaps in May, when its wood chips are in service to azaleas and dogs.