Whole Foods appears to be losing its loyal customer base.

The company's sales at stores open at least a year, or same-store sales, declined 0.2% last quarter, marking the first quarterly drop since 2009. So far this quarter, same-store sales are down 2.1%.

Whole Foods is hoping to stem the declines by increasing discounts.

"If we had a magic bullet, we've already shot it," Whole Foods co-CEO John Mackey said Wednesday on an earnings call. "We don't think there's anything we can do immediately except increase promotional activity to drive sales. We think it's basic blocking and tackling."

That means customers can expect to see a lot more sales on produce, meat, seafood, and other items in Whole Foods stores over the next couple of months.

Instead of just lowering prices across the board, stores will be highlighting more limited-time discounts, executives said.

Whole Foods is battling an increasingly competitive market for organic and natural foods.

"Our partners at United Natural Foods estimated over 70,000 new points of retail for natural and organic products over the last three years," Mackey said. "In this dynamic and increasingly competitive marketplace, we recognize we need to move faster and go deeper in creating a solid foundation for our long-term profitable growth."

Mackey said the company needed to do a better job of explaining to customers why Whole Foods' organic food was superior to the organic offerings at more conventional grocers, such as Walmart and Kroger, where prices may be lower.

Whole Foods will also be introducing a range of lower-priced products at its new chain of 365 by Whole Foods Market stores.

The company plans to open three 365 stores in fiscal-year 2016 and up to 10 stores in fiscal-year 2017.

Mackey says the new chain will be to Whole Foods what Nordstrom Rack is to Nordstrom.

"The time is right to take the high-quality standards we have developed over the last 35-plus years, and make them more broadly accessible through a streamlined, value-focused format and serve communities we would not be able to reach with our larger Whole Foods Market stores," Mackey said.