“Got mask? Come on in!” says a big sign outside Leitner’s Garden Center in St. Paul.

“It’s a request, not a requirement,” said Joan Westby, the store’s general manager.

But it’s been working. She estimates that 90% of customers are now wearing face masks, with some of them running back out to their cars to grab them.

As the economy begins to slowly reopen, wearing face masks is becoming the new expectation. Until there is a vaccine or other proven treatments for COVID-19, many public heath experts say widespread use of face masks, along with social distancing, will help limit the spread of the virus in the months to come.

Many grocery stores and retail shops are now requiring employees to wear face masks while encouraging customers to do the same. Costco is going one step further and will make them mandatory for shoppers starting on Monday.

Major airlines including Delta and American said last week that they, too, will start requiring passengers to cover their faces on flights.

Several states from New York to Illinois, Pennsylvania and Massachusetts also have put regulations in place saying residents must wear face coverings in public spaces such as in stores or while using public transportation.

Minnesota hasn’t gone that far yet, but last week Gov. Tim Walz encouraged residents to wear face masks in public as he announced a two-week extension of the state’s stay-at-home order. Under the revised order, more retailers can reopen on Monday for curbside pickup and delivery, with state officials recommending that workers wear masks and gloves as much as possible.

While it may not be “pleasant” to wear them, Walz said face masks will play an important role as businesses ramp back up.

“There is some pretty good data behind it that it might help you from infecting someone else,” he said. And, “I do think there’s a psychological piece behind it to show that we’re all in this together.”

The CDC, which initially said the public did not need to wear face masks, reversed course in early April and began recommending then that the public wear cloth face coverings in public settings where social distancing is difficult. Public health officials now say asymptomatic people could still transmit the novel coronavirus.

Last week, Vice President Mike Pence made headlines when he did not wear a mask during a visit to the Mayo Clinic in Rochester. After facing criticism, he donned one the next day when touring a General Motors plant in Indiana.

Wearing masks in public is “a big cultural shift for us,” but Americans are going to have to get comfortable with it, said Andy Slavitt, the former acting administrator for the federal Centers for Medicare and Medicaid Services.

“People are going to figure out that people are not going to get back into the economy — start spending, start traveling — until they feel safe,” said Slavitt, who lives in the Twin Cities. “One thing that absolutely helps people feel safe is if people have an N95 mask. There isn’t enough of those, so people are making do with homemade masks. They’re certainly better than not having a mask.”

Doug Loon, president of the Minnesota Chamber of Commerce, said that he expects some companies whose employees work in cubicles or other tight spaces will have workers wear some sort of masks when they return to the workplace.

In a mid-April survey of about 200 Minnesota manufacturers, 54% of them said they will start requiring workers in plants to wear masks, said Kirby Sneen, president of the Golden Valley-based Manufacturers Alliance.

“I wouldn’t be surprised if that increases in the next couple of months until there’s some sort of treatment readily available,” he said.

While it’s still unclear when entities like museums, restaurants, hair salons and gyms will be able to reopen, many are discussing whether they will encourage or require patrons to wear masks.

Chanhassen-based Life Time plans to have its employees wear face masks when it reopens its fitness clubs. It will follow state or local regulations as to whether gym members will be mandated to do so, said a company spokeswoman.

Richfield-based Best Buy’s workers also will be in face masks when the company reopens 200 stores nationwide this month for appointment shopping. In states where the public is required to wear face masks, Best Buy will provide masks for customers who don’t have them. In other states, such as Minnesota, it will encourage customers to cover their faces while also enforcing social distancing.

Many “essential” retailers that have remained open were initially hesitant to let workers wear masks. But as the federal guidance changed, many such as Walmart and Target have started providing workers with and requiring them to wear face masks.

Some workers, who have been troubled by shoppers standing too close to them without face masks, have been pushing retailers to mandate masks for customers, as Costco is doing. But many retailers are reluctant to do so.

Brian Cornell, CEO of Minneapolis-based Target, said recently that he’s been speaking with governors across the U.S. and is looking to them to provide direction and emphasize the importance of wearing masks in public.

When he goes into stores, Brian Yarbrough sees only about half of shoppers wearing face masks. Still, he said retailers, especially those that have been closed in recent weeks, are going to be hesitant to require shoppers wear them at a time when many are desperate for sales.

“These are difficult times,” said Yarbrough, a retail analyst with Edward Jones. “None of these retailers have ever seen anything like this.”

Enforcement also is an issue, putting employees in the potentially dangerous situation of having to confront customers.

“We don’t want our members to be the mask police,” said Jennifer Christensen, president of Local 1189 of the United Food and Commercial Workers, which represents grocery store workers. “That’s not necessarily a safe thing. You don’t want something that will bring you closer to someone not wearing a mask.”

Still, she said, her union strongly encourages customers to wear masks in stores to help alleviate the tension in areas of the store where there is a bottleneck or when customers walk up too close to workers to ask questions. In stores where workers are all wearing masks, shoppers are more likely to follow suit.

“Our members are safer if everyone is wearing a mask,” she said.

Some Twin Cities-area grocery store workers are just now getting face masks because of a shipment of them to a major chain in town was delayed, she added.

“It becomes a culture of shopping,” Christensen said.

Matty O’Reilly, who runs several restaurants including Bar Brigade in St. Paul and Republic in Minneapolis, has already told his employees that they will be wearing masks when he’s able to reopen for in-person dining.

“It comes down to consumer confidence,” he said. “So even if it’s not required, which I hope it will be, we’ll do it anyway. It’ll give guests an indication that we care about them.”

He’s planning to accept only reservations in the beginning to control the flow of traffic and will ask patrons to wear masks, too, especially when coming in and heading to their table.

“It’s going to be an adjustment on everyone’s part,” he said. “There’s going to be a learning curve.”