Cabbage Stump Night (or merely Cabbage Night) appears to be an American variant of northern England's Mischief Night, celebrated on the night before Halloween. Once again, it's something I had never heard of before. From newburyportnews.com:
Cabbage Stump Nights are not well chronicled. New Jersey apparently had its "cabbage night'' when cabbages were hurled at houses, but ours bettered that because cabbages do not fit small hands for throwing...
Cabbages have a distinctive and proper root for Cabbage Stump Night because it is the rubbery equivalent of a Little League baseball bat — pliant, easy to grasp and packing a mighty wallop.
Proper celebration of Cabbage Stump Night was to make a stealthy advance upon a peaceful household, beat the bejabbers out of the side of the house or the front door and skedaddle as fast as you could in the getaway. The alternative to escape was to receive a belt in the behind from the householder.
There would be no damage to the house because of the softness of the root, but the racket inside the house was a shock wave.