The answer to 'why is my landscape lighting dying plants' is that the landscape lighting may be causing too much heat or light exposure, which can stress and damage plants. Landscape lighting that is placed too close to plants, aimed directly at them, or left on for too long can disrupt the plants' natural growth cycles and lead to wilting, yellowing leaves, and even death.
Some common causes include: 1) Lights that are too bright or too close to plants, 2) Lights left on for too many hours at night, disrupting the plants' circadian rhythms, and 3) Lights that cast harsh shadows or uneven light patterns on plants. To fix this, you'll need to adjust the placement, brightness, and timing of your landscape lighting to better suit the needs of your plants.