but as fruit , the oranges failed ; they were best put to use by delinquents who exercised their growing limbs by kicking them or throwing them at passing cars and trains ; after decades of neglect most of the sour orange trees had become gnarled and stunted ; the tree themselves withered away to gray , ghostly stumps , then disappeared entirely , the empty wells remained for a decade after the trees were gone and then even the wells filled with dirt and disappeared .