Only short trees or shrubs should be planted under overhead power lines. Medium height trees should be offset at least 20 feet horizontally from power lines. Large trees should be offset at least 30 feet. Wider crowned trees such as elms or cottonwoods should be offset more than narrow crowned trees such as spruces. If you believe that you are planting in an area with underground utilities, call ND OneCall at 1-800-795-0555 to have utilities located and marked. 'Yes': tree species suitable for planting directly under a power line; 'No': not compatible.