Higher gas prices and the sagging economy have retailers expecting weaker spending for Mother's Day.

According to a survey of 8,180 consumers by the National Retail Federation and BIGResearch, shoppers are planning to spend an average of $138.63 on gifts, down from $139.14 last year. The most popular gifts this year include cards, flowers, dinner or brunch, gift certificates and clothing, though the overall number of buyers was down in all categories, the Washington-based trade group reported this week.

On the upside, total spending on jewelry is expected to increase this year from $2.1 billion to $2.7 billion, the survey found. About 30 percent of respondents said they planned to buy jewelry. Spending is also expected to be up on consumer electronics.

"Consumers will be very cautious with their wallets this Mother's Day, heeding mom's advice that she really doesn't need much," Phil Rist, vice president of strategy at BIGResearch, in a statement. He said high gas prices and other economic issues will likely be on consumer's minds as they shop for gifts.