Complex sentence: Since Apollo could no longer take her as his wife, he vowed to tend her as his tree, and used his powers of eternal youth to render her ever green; ever since then the leaves of the Bay laurel tree have never known decay.
Split into simpler sentences: Since Apollo could no longer take her as his wife, he vowed to tend her as his tree, and used his powers of eternal youth to render her ever green. Since then the leaves of the Bay laurel tree have never known decay.