Time is running out fast for consumers who haven't decked their halls or trimmed their tree. There's still more than a week before Christmas, but tree lots are emptying out.
"Demand has been very strong," said Oscar Slotarbeck, head of company surveys for ISI Group, which tracks Christmas tree sales. The weekend after Thanksgiving, sales rose 16 percent compared with last year—the biggest jump in the survey's 11-year history. Sales slowed a bit in early December due to winter storms, but were up 7 percent year over year.
Christmas tree purchases have waxed and waned with economic uncertainty. Last year, people bought 24.5 million real trees, down from 30.8 million in 2011, according to the National Christmas Tree Association. That, in turn was up from 27 million in 2010. Consumers who bought a tree last year reported spending an average $40.30.
Some of this year's boom stems from more consumers wanting trees, as well as more people buying early because there's one fewer week between Thanksgiving and Christmas this year, said Slotarbeck. But tree sellers hadn't anticipated higher demand.
"My sense is, a lot of the various sellers expected the season to be roughly the same as last year," he said. "Some of the retailers said things sold so well the first weekend, they were running low on some particular large, popular trees."
That may lengthen the hunt for families set on say, an eight-foot tall Fraser fir.
But consumers looking for a small tree will have an easier time of it. So-called apartment or condo trees—narrow specimens that top out at four feet, max—have become trendy, said Rick Dungey, a spokesman for the National Christmas Tree Association. "Ten years ago, you'd never have seen something like that," he said.
No matter how tall the tree, getting a good price can require calling around. Prices can vary widely, with some locations charging a flat rate for any tree on the lot, and others varying by height and tree species. Some outlets even offer coupons.
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And if the holiday season is getting hectic, there are more options to have a fresh-cut tree shipped this year, said Dungey.
Online car service Uber ran a one-day promotion offering home delivery of a 7- or 8-foot Fraser fir and stand for $135; Home Depot, Target and Sears, as well as Christmas tree farms, also ship fresh-cut trees—cut on the farm at the time of your order—nationwide.
This late in the season, online prices are already dropping, although you'll still pay a premium over lot rates. Target recently knocked 25 percent off its tree prices, with a five-foot Fraser selling for $99.94 instead of $133.26. At Sears, an eight-foot Fraser goes for $152.99, a $17 discount.
—By CNBC's Kelli B. Grant. Follow her on Twitter .