Detroit's Department of D.I.Y. is either the most heartwarming or humiliating reflection of its distress, but the volunteers insist it shows their refusal to give up on the place where they live.
"When the system fails us, you have to become the system," said Mitch Logan, 48, a film producer who is part of a self-dubbed "Mower Gang" whose members mow neighborhood parks after finishing their own yards.
In addition to the landscaping, a church group is boarding up vacant houses in Brightmoor, one of the city's most distressed neighborhoods, to keep criminals out. And several neighborhoods are hiring security to patrol their streets, supplementing an understaffed police department.
As for the new cars, "It is unprecedented for us to help buy emergency vehicles or police cars," said Rip Rapson, chief executive of the Kresge Foundation, which joined with Detroit's automakers and other businesses to make the purchase. However, "this was the kind of expenditure they could not find in their budget."
Detroit's problems have been a national spectacle for several years, the result of the region's long economic slump and of past mismanagement that squandered city resources. By the time emergency manager Kevyn Orr took over city finances in March, local government was $327 million in the red and had gone through rounds of layoffs and cuts.
Bus service has been reduced or discontinued on about three dozen routes, leaving thousands of daily riders to find other ways around town. Libraries and recreation centers began closing extra days for employee furloughs and trash trucks were delayed because of breakdowns.
There are 2,600 police officers, down from 4,000 a decade ago.
The city's parks were in danger of becoming a particular eyesore. Until donors stepped in, the city planned to close almost half of them. Still, mowing on many is scheduled only every three weeks.
"It's a disgrace to the nation, a disgrace to the state," said Harriet Cammock, a writer who moved to the suburbs because of the deterioration.
Tom Nardone of suburban Birmingham, owner of an Internet novelty business, started the Mower Gang. Through word-of-mouth, his website and Facebook, the group has grown to more than 20 regulars who take care of eight or nine parks where the weeds were too high for children to play. He hopes to keep expanding.
Katherine McFate, chief executive of the Washington-based Center for Effective Government, said that she understands the need but that Detroit should be wary of letting donors go too far.
"The idea that we are now outfitting first responders through charitable contributions should be very concerning," she said. "There are certain functions that you want government to perform that should not be at the whim of individuals or charities."