No single activity can improve the immediate health of urban trees more than maintenance. Once a tree becomes part of a community, it occupies a spot for a long period of time. Keeping trees alive, healthy and safe requires a considerable amount of maintenance. Cities are trading off the maintenance budget for planting and removal. They are in the business of being tree morticians rather than tree-health experts.
Maintenance includes pruning, fertilizing, damage repair and control of pest problems.
Trimming is the single most important item, making up about 80 percent of the maintenance budget. Trimming or pruning is most effective when it is started early in the life of the tree. Nipping a problem in the bud allows workers to use small tools to make cuts and haul away debris. It allows the tree to expand its energy on growth that improves its shape and health, and prevents the large wounds that are caused by the removal of bigger branches. Maintenance should be a planned activity.