The owner of a popular Staten Island pharmacy gave Mayor de Blasio an earful Friday about the borough’s growing homeless problem — especially how one drunken vagrant accidentally set his business on fire.

The mayor, who spent the week on Staten Island as part of his “City Hall in Your Borough” program, dropped by St. George Pharmacy for a brief tour of the gutted interior that still reeks of smoke following the June 6 blaze.

Owner Al Gentile told de Blasio that “homeless panhandlers” regularly occupy the sidewalks on his Stuyvesant Street block, harassing customers and others passing through the main commercial corridor.

Gentile said his 35-year-old property also endured drunk homeless men “sleeping it off” while leaving behind “boxes, beer bottles and vodka bottles.”

Squatter Hector Meza, 40, is facing arson charges for accidentally knocking over a lit candle on Gentile’s porch. He reportedly tried to put the fire out by urinating and pouring beer over it.

“Is there a place at night for them to go? Is there something else you can do?” pleaded Gentile.

De Blasio then boasted about how his administration has gotten thousands of homeless “off the street” and has begun offering “more job training” at homeless shelters.

When told by Gentile that the homeless people sometimes get very aggressive, the mayor then vowed such behavior “would not be tolerated” and promised to use city resources to deal with the problem.

“I hope he meant it,” Gentile told The Post afterwards. “The mayor seemed to listen. “These [homeless people] drink all day and idle on the sidewalks and won’t leave. I feel bad for them and want to help them out, but it is not my job to do it.”

Gentile, who employs eight staffers, said he hopes to be back in business within three to five months.