Create a shady meeting area in the garden and spend time there. Invite everyone in the neighborhood to participate from the very beginning. Persons excluded from the garden are potential vandals. Involve the neighborhood children in learning gardens. They can be the garden's best protectors.
Plant raspberries, roses or other thorny plants along the fence as a barrier to fence climbers.
Make friends with neighbors whose window overlook the garden. Trade them flowers and vegetables for a protective eye. Harvest all ripe fruit and vegetables on a daily basis. Red tomatoes falling from the vines invite trouble. Plant potatoes, other root crops or a less popular vegetable such as kohlrabi along the sidewalk or fence.