One other possible solution to repel the pests is to spread ground Cayenne Pepper all around the area. You can also try mixing the pepper powder with peanut butter as bait and then placing the bait at stations around your plants. Eating the bait may be unpleasant enough to convince the pests to go somewhere else.
Of course, the only permanent solution (for your location in a city) is lead from a high-speed pellet rifle.
