Enlarge Image The city has been looking a whole lot rosier in these dark days — and it’s all thanks to Lewis Miller .

The Chelsea florist — who’s been hailed as a botanical Banksy — has been sneaking around Manhattan and Brooklyn making the sidewalks unexpectedly bloom.

Miller, who first started his now-infamous Flower Flashes nearly four years ago, in October 2016, leaves fanciful, over-the-top floral arrangements in public spots around the city — adorning Central Park benches and statues, springing up in front of museums like the Whitney, and even sprouting out of trashcans in 4-foot-tall bouquets.

Now, in the wake of the coronavirus that’s left the city at a near standstill and left Miller’s usually full dance card completely empty, the 46-year-old floral designer has been determined not to wilt under the weight of the pandemic. Instead, the founder of his namesake floral company, which specializes in event design, put the petal to the metal and created installations that are as heartfelt as they are gorgeous.

On Tuesday, a flower bomb went off in NYC: Miller and his team festooned several city locations with breathtaking arrangements, including a “I [Heart] New York” display in Gansevoort Plaza creating a lush love letter to a broken city. On the florist’s Instagram account , which has more than 164,000 followers, he wrote: “The heartbeat of NYC is its people and we can’t wait [to] be close to you all again.”

Now that’s flower power.

Miller, who opened his business in 2002, tells The Post he creates his surprise street spectacles simply “to give back. We all needed happiness before the pandemic, but now more than ever.” He adds that his bouquets “have no other responsibility in this world than to bring joy and happiness.”

He created his first public art project at the Imagine mosaic inside Strawberry Fields, Central Park’s John Lennon memorial, and continued to gain worldwide attention for impromptu displays in the most unexpected spots.

“I’m now — officially, or not — the guy who puts flowers in trashcans,” he says.

His on-the-fly Flower Flashes are plotted quickly. Miller says he’ll spend “15 seconds or less” sketching his vision and color schemes. A team of four will set out pre-dawn — loading up the van by 5 a.m. — to a location that’s been scouted by a friend, and in less than 30 minutes, “I’m out of there,” he says.

“We keep it moving fast. It’s a total dopamine rush,” he says. “We don’t ask permission, we ask forgiveness.”

(While there haven’t been any brushes with the law, he does have to deal with another difficult breed: “Some cranky doormen on the Upper East Side,” he says.)

Although his business has been battered by the coronavirus, Miller says that he wanted to buoy the spirits of the city. “I was thinking, ‘Are we going to keep doing them? How are we going to make payroll?’ ” But, he says, “at this point, it’s almost become a responsibility.” ‘I’m now — officially, or not — the guy who puts flowers […]