The answer to 'why is my landscape lighting dead trees' is that the landscape lighting may be causing damage to the trees. Landscape lighting that is placed too close to trees or that shines directly on the trunk and branches can actually stress the trees and lead to their decline.
The most common symptoms of landscape lighting damaging trees include wilting leaves, discolored or dying branches, and eventually the entire tree dying. This happens because the intense and prolonged lighting can disrupt the trees' natural growth cycles and photosynthesis processes. If the lighting is not adjusted or relocated, the trees will continue to weaken and eventually die.