I don't know what to call these - alley glories? They grow all around my neighborhood (southwest Center City Philadelphia - south of South St, west of Broad St.) as volunteers in vacant scraps of land & pavement cracks and also being grown in people's gardens or sidewalk pots. This row house neighborhood was developed around 1910-1915ish, so they could be garden escapees dating back as far as that. Or farther, if they came from adjacent neighborhoods.

The wild ones have fewer and somewhat smaller flowers; when I brought them into my garden the vines grew much bigger leaves. I haven't really given them any special care beyond some supplemental water at the outset and some worm castings when they were planted. True to form, they didn't like being transplanted as seedlings and took a while to settle in, but now they are happy as can be and clambering all along my patio fence. (There are two vines here: I planted three seedlings and one didn't make it.)

From appearances (heart shaped leaves) it is Ipomoea purpurea, and the closest color match I can find by lots of image Googling is "Crimson Rambler," which is undoubtably a heirloom variety. Does it look recognizable to anyone?