Procrastination can pay for last-minute sports tickets or 11th-hour holiday bargains. But when it comes to retirement savings? Bad idea.

More than half of middle-class Americans say they plan to save more for retirement "later" to make up for not saving enough now, according to a new Wells Fargo survey. Worse, many aren't saving at all—34 percent of the 1,001 adults surveyed aren't currently setting money aside for retirement and 20 percent have no retirement savings. The median balance among savers is $20,000, down from $25,000 last year.