TAMPA — In one corner of the collaborative art space, a group of teenagers paint portraits of Peruvian faces as part of a fundraiser for the people of the Moche Valley, their pants and forearms swiftly streaked with bright acrylic colors. In another, there's a sale on craft supplies like buttons and ribbon and soda pop tops. And against the north wall … what is it? Since mid March, a wall of the Roosevelt 2.0 in Ybor City has been transformed into something miraculous, part visual art, part performance art and part lunch.Dave Smiles of Uriah's Urban Farms built it, tending 2,300 to 2,600 plants that make up a green living wall. The basic idea is not hard to understand: Commandeer unused urban space to grow things to eat. But it gets high-tech pretty quickly.Eight-foot-tall, double-walled, food-grade stainless steel grids are filled with peat moss, pearlite, vermiculite and coconut shell chips, then a tiny seedling. There are three types of tomatoes, four types of peppers, fairy eggplants, a riot of herbs, five types of lettuce, squashes and greens. These are grown up the wall with compact fluorescent grow lights mounted on commercial light movers mimicking 14 hours of spring's sun. Water drips from sprinklers at the top of the panels, the trickle running via gravity down the face, none of it lost in the process.Because it is indoors, there is no need for pesticides or other chemicals. There is no harmful agricultural runoff or pollution. Depending on the crop, it's 30 days from seed to plate. Ah, and what plates.Smiles takes down panels of ripe plants a couple of times a week and ferries them to Mise en Place, where the mobile garden unit performs double duty, as lush floral arrangement at the entrance, but also as a salad source: Customer orders Farmer Dave's salad. Server zips to the wall and pinches off raspberry oak leaf, red buttercrunch and lime oak leaf lettuces, a little arugula, rainbow chard and basil. From there, they are plunged into ice water, dried with a soft white towel and tossed with a vinaigrette, almonds and croutons. Can't get much fresher than that. Mise en Place, owned by Marty Blitz and Maryann Ferenc, isn't the only customer. Armani's, Oystercatchers and Petey Brown's at the Grand Hyatt are regulars, as is Chad Johnson, the chef at SideBern's. The soon-to-open Epicurean Hotel will have a green wall that Smiles designed.Smiles' vision goes beyond providing savvy local chefs with living produce. In the future, he sees these vertical farms as an alternative to our current food distribution system. He speaks about environmental impact mitigation, about pollution reduction, about eliminating metals and other pollutants from our water system and slowing deforestation. And then there's nutrition."In the traditional agriculture system, vegetables are picked green and then gassed to appear ripe and then shipped long distance, devoid of life and nutritional value," he says. "Our current system is a tragedy."Man on a missionSmiles was raised in Tampa in an entrepreneurial household. By 17 he had an aquatic landscaping business building ponds and water features. From there, his fascination with aquatic plants and hydroponics grew.For years he ran a 10-acre farm in Lithia called Uriah's Gourmet Lettuce and Fine Herbs, and then three years ago, he was hired by a green roof and wall company in Rochester, N.Y., to develop a version of the system he uses at the Roosevelt. It was while promoting the product at the Tampa Bay Green Living Expo that he met the folks behind the Roosevelt 2.0."There was a high degree of synergy between what I was trying to do and what the Roosevelt was doing."Begun in 2008 in a condemned building, the Roosevelt celebrates the creative arts and incubates innovative solutions to social challenges. And so at the beginning of the year, Smiles rented 120 square feet of space and started farming. But his vertical farm at the Roosevelt is just the beginning, an example of what is possible even for urban dwellers with limited access to fresh produce.Smiles is in negotiation to rent a notable (and huge) downtown building where he envisions a large-scale vertical farm with a you-pick component, farmers' market and commercial kitchen space for local food-centric businesses — what he hopes will be "a food hub in Tampa." He talks about using solar panels, "anaerobic digestion machines" and other renewable energy sources to take the farm "off the grid" and to decrease the cost of production (electricity constitutes the biggest expense with this kind of farming).For now, though, he tinkers with how to maximize production in his historic Ybor City building. He has grown watermelon on the wall, really everything but corn. Celery doesn't do so well in the vertical system, he says, as he narrows his eye, speaking down to the basil seedling in his palm."They don't talk back, but they've taught me a lot."Smiles has to stop tending the plants regularly to explain what he's doing as people wander into the art space."Everyone asks, 'Is that art?' And I say, yes, it's living art. Food can be pretty, too."Laura Reiley can be reached at [email protected] or (727) 892-2293. Follow @lreiley on Twitter.