How do I plant a tree around utility lines? Overhead Lines Overhead utility lines are the easiest to see and probably the ones we take most for granted. Although these lines look harmless enough, they can be extremely dangerous. Planting tall growing trees under and near these lines will ultimately require your utility to prune them to maintain safe clearance from the wires. Trees which must be pruned away from power lines are under greater stress and more susceptible to insects and disease. Tall growing trees near overhead lines can cause service interruptions when tree contact wires. Proper selection and placement of trees in and around overhead utilities can eliminate potential public safety hazards, reduce expenses for utilities and their rate payers and improve the appearance of landscapes. Underground Lines. The biggest danger to underground lines occurs during planting. Before you plant, make sure that you are aware of the location of any underground utilities. To be certain that you do not accidentally dig into any lines and risk serious injury or a costly service interruption, call 1-800-922-1987 or visit Utility Notification Center of Colorado first. Never assume that these utility lines are buried deeper than you plan to dig. In some cases, lines are very close to the surface.