The answer to 'hedge dead trees' is that dead trees in a hedge need to be removed and replaced promptly. Dead trees in a hedge can pose safety risks, detract from the aesthetic, and allow pests and disease to spread to the rest of the hedge. The most common causes of dead trees in a hedge are drought, disease, or damage from pests or harsh weather.
You'll first want to identify and remove any dead or dying trees in the hedge. This is best done by a professional landscaper, as they can safely remove the trees and properly dispose of them. Once the dead trees are removed, you'll need to plant new trees or shrubs to fill in the gaps and restore the hedge's uniform appearance. Be sure to select plants that are well-suited to your local climate and growing conditions.