The Greenest Block in Brooklyn is being trashed by careless merchants and apartment dwellers, say those who are trying to keep the block beautiful.

Residents of Vanderveer Place between Flatbush Avenue and E. 23rd Street — which won the Brooklyn Botanic Garden’s coveted “Greenest Block” award last year — say some people who live and work in stores and the apartments above them on Flatbush are dumping everything from household trash to mattresses at the Flatbush end of the tiny street, and smaller pieces of detritus dropped by passersby end up blowing in front of their houses.

“We sweep our sidewalks and a half an hour later it’s dirty again,” said Nadine Hajjar. “It sabotages everything we do.”

But it’s not just gum wrappers and used coffee cups mucking up the place.

“We have people pulling things out of their apartments — a sofa, lamps, a TV, all on the corner,” said Yvonne Murray, who added that “the furniture places come along with mattresses, and it’s mushroomed into one big mess.”

Residents of the block have brought their complaints to Community Board 14, who’s district manager, Doris Ortiz, says Department of Sanitation official will soon be by to look at the mess firsthand.

And the city has already removed the public trash can at the corner in the hopes of lessening the amount of trash that spills onto the street — but residents say that hasn’t solved a thing.

“All the cans on the corner did was provide a place for people who live along Flatbush to leave their garbage,” said Murray. “Now, there are no cans, and they drop it on the ground.”

But a Sanitation spokeswoman said that inspectors didn’t see major dumping when they checked the area after a call from us.

“It is not a dump-out area,” said Kathy Dawkins. “There seems to be a pile of dirty snow on the corner, and as a result, people are leaving bags. The rest of the block is fairly clean.”

Residents of the reigning “Greenest Block” disagree, and think that the city needs to step up the ticketing of litterers.

“People continue to do it because no one is stopping them,” Johnson said.