These are the grape vines that take over whole lots and smother large trees. When they get to tree-smothering size, they produce thousands of these little grapes, which are intensely flavorful and quite tart. They sweeten a bit after a frost. The grapes hang on into the winter; these were hanging on a huge vine in Beechview in late November. Below, a typically monstrous mound of Frost Grapes on the South Side Slopes.