But there's still plenty of work to be done in the area.
Just a stone's throw from the lush, green urban paradise at 27th and Silver is a nagging reminder of the sheer hell that remains in parts of the neighborhood.
The people who stop by the garden come away with cucumbers and bell peppers. But a few steps away, at 27th and Sterner, they leave with crack-cocaine and marijuana.
The persistent problems of drug-slinging and violence just steps away from the symbols of how far the North Philadelphia neighborhood has come illustrate the challenge that long-blighted neighborhoods face. When community members stand up and say "enough is enough" on one block, surrounding blocks can be left to fend off displaced crime and drug activity - in addition to issues they may already have.
Residents near 27th and Sterner say that when night falls, they're held hostage by hordes of drug dealers who run the corner.
"I see a lot more police presence, but there's drug activity still," said 12-year resident Darnell Mann as he stood on the corner of 27th and Silver with 39th District Police Capt. Verdell Johnson on a recent afternoon.
"You all are doing what you can do," Mann told the captain. "But still, there are a select few for years causing havoc around here."
Johnson promised Mann that the area is on its way to more change. He said that a revolving door in the criminal-justice system makes it difficult for cops to keep the resident badasses off the streets.
"It's better now, over the last few years. It's not perfect," Johnson said. "The problem is, you have a core group of knuckleheads, and it's hard to keep them in jail."
Pulling a spreadsheet out of his pocket, Johnson rattled off a list of crime statistics comparing this year to last. The stats mostly indicate headway made by cops in the 39th District, which encompasses North Philadelphia's Swampoodle neighborhood, where PhillyRising is working, and swaths of Allegheny West, East Falls and North Philly.
According to police stats, homicides are down 24 percent in the district through mid-August. The number of shooting victims is even with last year's, while illegal-gun arrests are up 32 percent.
Part of PhillyRising's work included posting "No loitering" signs at the request of neighbors. One looms over the drug corner at 27th and Sterner, and Johnson said that police have made good on their promise to curb that problem. Arrests for loitering are up 89 percent.
"And I've got less cops," Johnson said.
Officer Joe Lukaitis, who's worked in the district since 1996, has made it his mission to look after the PhillyRising area, even helping with neighborhood cleanups on his days off.
As Kennedy admired the garden, Lukaitis stood nearby, eyeing the plants and talking tomato-growing strategies with the gardening neophyte.
"You should get some wood and put up stakes," he told Kennedy.
Being a cop in the district for 16 years, Lukaitis said that he's seen the area ebb and flow. Since PhillyRising's work, he said, things have improved.
"You can see it yourself," Lukaitis said. "The blocks are cleaned, maintained."
Indeed, Kennedy's block of Silver Street - roped off as a "play street" that provides a safe haven for his grandsons, ages 3 and 4, to romp - is clean. Another neighbor, Lamont DeShields, 67, built his own garden, inspired by the PhillyRising garden.
"If you could have seen this place prior to us getting together, you'd be amazed," DeShields said as he walked to his own garden overflowing with squash and tomatoes. "Out of all the negative in our community, we've got a group that refuses to be negative."
But for residents on crime-plagued Sterner Street, one side street closer to Lehigh Avenue, it's a different story.
"It's gotten worse," said Joanne McKinzy, 44, who's lived on Sterner since 1999 and often sweeps her side of the block after waking up to find the street strewn with trash, day in and day out.
McKinzy pointed out an overgrown abandoned lot about three house lengths on the block, which is dotted with crumbling vacant houses.
"This lot right here's been like that for years," she said. "It's atrocious. It looks like 'Jurassic Park.' "
About a year-and-a-half ago when she attempted to clean up the lot herself, she said, she suffered a bug bite to the eye that bought her a trip to the emergency room.
"It's the fleas. It's the ticks," she said, shaking her head. "It's the people sometimes, too."
Overgrown lots and derelict houses are hardly the most nefarious problems plaguing McKinzy's block.
In March, at the eastern end of the block, police said, ex-con Eric Locke, 32, shot and killed Joel Blumer, 53, who owned a check-cashing store there, during a robbery.
According to crime reports on the Philadelphia Police website, there have been six aggravated assaults with a deadly weapon within a three-block radius there since the beginning of August.
On Saturday, with help from the city, neighbors on Sterner Street banded together and held a cleanup on their block, clearing some of the overgrown lots.
"It took them long enough, but I'm happy," McKinzy, who participated in Saturday's cleanup, said on Sunday. "But it's up to the neighborhood to keep it together."
Kennedy said that he and other neighbors have more cleanups planned for the block of Sterner Street, just west of 27th, and a handful of other side streets.
"The effort to keep the blocks clean has been spreading," said city Assistant Managing Director Jim Sanders, who runs PhillyRising's Northwest Division. "This will be a definite indication to the unsavory individuals that people do care about this block and are watching what's going on."
Officials and experts said that although it might be tough to push out a long-standing tradition of crime, blight and violence in an area like Swampoodle, things like the garden uplift the community and serve as deterrents.
Chad Dion Lassiter, president of Black Men at Penn and a race-relations expert, said that underneath it all, the people pushing drugs on the corner are living in fear, too - but it's up to the law-abiding community members to pull together and scare them off.
"It changes the context when the environment is cleaned up because then you have more people outside and more people are watching and not as prone to engage in those types of behaviors, because you don't know what the community is thinking," he said.
"The drug dealers are scared. . . . If 30 committed men in the community rolled up on two drug dealers and said, 'Get off the corner,' the drug dealers would leave."
Standing in the garden, Kennedy gave his own account of how that theory works.
"There are no drug dealers on my block because I moved them off the block and shut down the drug houses," he said. "We're trying to better the area. It's good people in North Philly that can change it over."
Contact Morgan Zalot at email@example.com or 215-854-5928. Follow her on Twitter @morganzalot. Read her blog at PhillyConfidential.com.