The answer to 'why is my fence dead trees' is that dead or dying trees near a fence can often cause damage to the fence structure. Common causes include the tree's roots growing into and disrupting the fence posts, or the tree's branches and weight causing the fence to lean or collapse.
Symptoms of this issue may include leaning fence posts, gaps or holes in the fence, or the fence pulling away from the ground. To resolve the problem, you'll likely need to remove the dead or dying tree, and potentially replace any damaged fence sections. Depending on the extent of the damage, this may be a DIY project or require a professional landscaper or fencing contractor.