Nursery - The Tree Authority goal is to give trees the best chance to survive in an urban landscape, right from the nursery. Run by an ISA Certified Arborist, the nursery uses best practices to grow strong, healthy trees with virtually no girdling roots, no transplant shock and a visible root flare. Tree Service - The Tree Authority Goal is to provide services that help owners plant, care for and preserve trees. Pruning and tree health care are our specialty. A good pruning job will ensure a tree that is healthier and safer while preserving the natural aesthetic of the tree. No topping or hack jobs allowed!