Bull nettles

what seems to work for me is to mow (with a powered mower , I use a ride on ) early , at dawn just as they are waking up , it makes one hell of a mucky mess inside the drum ,stinks too if you dont wash them off , 3 or 4 days and there are few left

Move them after dark and they will not notice they have been moved

  The one thing to watch with peening is that it work hardens the steel then it cracks , A good blacksmith will forge weld any cracks that appear