Question
When is the correct time of the year to trim Oaks (red) and Maples.

Answer
The best time to prune deciduous trees is late winter or early spring (February, March, and early April) before they begin to leaf out. Some trees, such as maples, "bleed" heavily when pruned in late winter or early spring. However, the heavy bleeding doesn't harm the trees. The trees won't bleed to death and the flow of sap will gradually slow and stop.

To prevent the spread of oak wilt, avoid pruning oaks from April 1 to July 1. Pruning oaks during this period may attract sap beetles carrying the oak wilt fungus to the pruning cuts and transmit the disease to healthy trees. An excellent time to prune oaks is February and March.

If possible, avoid pruning deciduous trees in the spring as they are leafing out. At this time, the tree's energy reserves are low and the bark "slips" or tears easily. Another poor time to prune is during leaf drop in the fall.