How Much Watering Evergreens Need in the Winter?

In most of the Midwest Winter watering is almost never necessary as there is enough precipitation to keep the Green Giant Arborvitae or Murray / Leyland Cypress alive. Water demand for these trees falls to a fraction of what it is during the Summer and competition for water intake is limited to other evergreens only. The ice slowly melting also gradually makes water available for the trees.

However unlikely it is, at least in theory, long stretches of no precipitation such as 6-8 weeks is still possible. In such cases recently planted trees could become susceptible to to be damaged by lack of water.