Claudio Toca, of Woonsocket, ties a tree to the roof of his car after cutting it at the Petersen tree farm in Glocester.

The Providence Journal / Glenn Osmundson

GLOCESTER — It may be the year of the Charlie Brown Christmas tree.

Businesses that sell natural Christmas trees and the greenery that goes along with them are keeping a watchful eye on their parking lots — and the calendar — hoping Rhode Islanders soon will be in the mood to spend money on a holiday evergreen.

“I’m assuming it will be the same” as last year, said Jim Petersen, owner of the Petersen tree farm on Putnam Pike. “People who like to get a fresh-cut Christmas tree will put money aside for that.”

Petersen sells several hundred trees each year, all of them grown on his roughly 85-acre farm.

The number of natural Christmas trees sold in the United States has been on a generally upward swing since 2002, when Americans bought 22.2 million natural trees, according to statistics kept by the National Christmas Tree Association. Last year, 16 percent of the 31.3 million natural Christmas trees sold in this country were cut by people who headed out to the nation’s independent tree farms.

“I like the smell of it in the house,” said Claudio Toca, who had traveled to Petersen’s farm from Woonsocket yesterday with his wife and daughter.

The family spent about 20 minutes walking the soggy front field of Petersen’s property before settling on a 5-foot, 6-inch spruce that they loaded on to the roof of their Ford Taurus sedan. They paid $25.

The Tocas were among the smattering of Rhode Islanders yesterday who carted home a Christmas tree.

Thanksgiving weekend is typically a time when people “tag” trees at farms; paying for an evergreen in advance of cutting it down sometime in early December.

The same goes for the garden shops and the temporary retail stands that pop up at this time each year. Most sales occur on the first two weekends of December.

It’s too early to tell how economic forces will affect these holiday businesses, which last year got smacked by high gasoline prices and the value of the U.S. dollar.

About a quarter of the natural trees were bought last year at big-box chains such as Home Depot — just one of the national chains whittling away at the holiday season business done by garden shops, temporary retail lots and nonprofit groups.

Canadian tree growers set contracts with U.S. wholesalers in August. Last year, the Canadian dollar was worth about 90 U.S. cents at the time those contracts were set and then fell back to par by Thanksgiving.

The exchange rate is back to a more typical relationship, with the Canadian dollar worth about 81 U.S. cents.

The national average for regular unleaded gasoline was $3.06 per gallon at this time last year. After hitting a record $4.11 on July 15, the average price of a gallon of regular gasoline is $1.91, down 54 percent, according to AAA.

That has Erica Toca in a good frame of mind.

“It’s good to take a positive view,” she said of the price drop.

But it’s not the gasoline prices or exchange rate that has businesses wary this year, but the general economy.

Gregory Murray, owner of Chepachet Hardware, has more trees priced in the $12-to-$25 range — 2- and 3-footers suitable for the mopey cartoon character created by Charles Schulz — than in years before.

“I made changes to my purchasing because of that,” Murray said. “I scaled back on my large trees and I beefed up on the small ones.”

pgrimald@projo.com