Warm weather ushers in back-yard barbecues, swimsuits and door-to-door sales that could be scams.

Richard Larson, owner of RL Automotive in East Bethel, was heading to lunch last week when a guy eyeing a broken area in his parking lot said he happened to have some extra asphalt and would give him a good deal.

Larson described the area he wanted repaired, but when he came back after lunch, the contractor had already repaired an area four times greater than they’d agreed upon and presented him with a bill for $5,000.

“We went back and forth about the bill and settled on $4,000,” said Larson. “The workmanship was fine, but at way too high of a price. It was a scam, and I should’ve known better.”

Asphalt resurfacing, meat sales, tree trimming, magazine subscriptions — they’re some of the goods and services sold by solicitors who make house calls in the summer. The Better Business Bureau of Minnesota and North Dakota wants people to have a plan when they’re confronted.

“Though many door-to-door salespeople operate honestly and represent reputable businesses, there are others who are looking only to make a sale and move on as quickly as possible,” warned Dan Hendrickson, communications coordinator for the BBB of Minnesota, in a statement.

Carol Vogstrom of Plymouth hired a tree trimmer who came to her door in March. “He talked price up front, $635 to trim two oak trees, but that was supposed to cover hauling away the debris,” she said.

The trimmers said they would be back the following day with the wood chipper to remove the dead branches but never returned, despite many phone calls.

Vogstrom blames her mistake on timing.

“It was very convenient to have them show up because I knew the trees needed trimming and that they were supposed to get trimmed before the weather was too warm,” she said. “That clouded my judgment.”

Bob Hignite of Lanesboro, Minn., said he sees several door-to-door salesmen canvassing his neighborhood every summer.

“I watched the asphalt guy go house to house like ‘The Music Man,’ ” he said.

When Hignite asked how the work would be done, he was told there would be no edging or base gravel put down over his dirt driveway. “People think they’re getting a good deal, but it’s more the convenience factor,” he said.

Meat sold door-to-door under the guise of a truck that broke down nearby or an overstocked restaurant is nearly always a worse deal than at the grocery store, said Ann Walters, food standards compliance officer for the Minnesota Department of Agriculture’s dairy and food inspection division. “A legitimate salesperson will tell you the price per pound,” she said.

Walters reminds consumers that any door-to-door purchases have a three-day rescission, or cooling-off, period, in which the consumer may cancel purchases costing more than $25. The company must provide a refund within 10 days as long as the item sold is in its original condition.

Consumers also should ask for identification, including an ID and business card. If the salesperson is offering meat, for example, ask for the retail food handler’s license for selling meat.

Hendrickson said the Minnesota office has received 75 complaints about door-to-door sales in the past 12 months. People who have concerns can file a complaint at BBB.org or with local law enforcement or the Minnesota attorney general’s office.