Silver Maple trees are a widely planted shade and landscape tree. They grow very quickly and produce attractive yellow foliage in the fall. The average size is 60 feet tall and 30 feet wide, but in their native range they grow much taller. Although Silver Maples can adapt to alkaline soils and dry conditions, they prefer to live in deep, moist and acidic soil. Silver Maples are a short lived tree and the limbs are often brittle and break away easily in high winds. For that reason, it is advisable to plant a Silver Maple at least 50 feet from a structure.
Look at the Silver Maple and locate the drip line of the tree. This is the ground that is under the outer edges of the canopy. The feeder roots or the roots that absorb water are located near the surface and halfway between the trunk and the outer edge of the drip line. There are more feeder roots located the same distance outwards from the drip line. For example, if the distance between the tree's trunk and the drip line is 10 feet, then the highest concentration of feeder roots is located from 5 feet from the trunk to 5 feet beyond the drip line.
Figure the minimum amount to give your Silver Maple. All trees, including the Silver Maple, should receive 10 gallons of water for every inch of trunk diameter. For example, if a tree is 7 inches in diameter, it should receive 70 gallons of water. It takes about five minutes for a typical garden hose running with a medium flow of water to deliver 10 gallons. So you would need to water for 35 minutes with a medium water flow. Lay the hose in the target area and move it around the target area during the watering period. Watering directly against the trunk causes the base of the tree to develop rot or mildew problems.
Water the area where the feeder roots are located every two weeks during the driest part of the year or if the tree seems stressed. Silver Maples are capable of sitting in waterlogged soil for long periods of time, so you cannot overwater a Silver Maple located in your landscape. It will not hurt the Silver Maple to give it more water in the watering zone than the minimum recommended.