Water that roots can access is of paramount importance to the health of a tree. The most effective application of water for city trees is achieved by saturating a portion of the roots to a foot or more of depth. To do this efficiently, turn on the water at a very slow trickle and let it run in this position for an hour. This should be done once or twice a week, depending rainfall and temperatures. By ensuring at least some of the tree’s root system has water, the tree can then effectively move it throughout the plant. Consistent availability of water is essential from May to early August, as these are the growing months. For young and newly planted trees, water near the base of the trunk but for more mature trees place the trickling hose around the canopy edge, where possible, as these are the most active root-growing areas.