爱到浅时叶自败爱到深处花自开
[ài dào qiăn shí yè zì bài ài dào shēn chŭ huā zì kāi]
Poetically illustrates stages of love—when it fades (like when a plant withers from shallow affection) and blossoms ('flowers bloom' indicating fulfillment and beauty from profound passion).