Philadelphia is a vibrant horticultural center, with much history and many thriving gardening organizations, public gardens and traditions. But it was even more of a hotbed in the 18th and 19th centuries - starting with botanist John Bartram, moving on to seedsman David Landreth, continuing with Henry Dreer, who introduced the hanging basket, and many others. This year is the Landreth Seed Co.'s 225th birthday, a milestone that finds the company in the capable hands of Barbara and Peter Melera. Although the firm began in Philadelphia at 12th and Market (then High) Streets, eventually it moved to Baltimore. When the Meleras bought it six years ago, they moved everything to New Freedom, Pa., outside York. Baltimore's crime was a factor in their decision to move, Barb says. Now they're in farm country, trying to make a go of a business that, when they took over, was 95 percent focused on selling grass seed. Nothing wrong with that, except there's a lot of competition and profit margins are low. So Barb decided - for she is the motor that drives this engine - that she wanted to get back to David Landreth's original mission, which was to "find and sell good quality American seed and help Americans to be better gardeners." She's building the business back up - it'll never be as big as it once was and Barb has no desire to create a monster - as a place for heirloom vegetable, flower and herb seeds. I had a long visit with her last week. She walked me around the 7,200-square-foot warehouse, which used to house racing cars, let me poke around the drawers and bins full of petticoat daffodils that date to 1629 and other vintage treasures, and she shared old leatherbound volumes of Landreth seed catalogues. Barb couldn't be more excited. A former venture capitalist, an MIT grad who grew up wanting to be an astronaut, she's not to be messed with! And although she has no Landreth DNA, you'd be hard pressed to find a better stand-in. Story to come on Friday.