The poem "Virtue" is about how life is completely transitory; it ends. Herbert uses a rose, a day, and spring to illustrate how life ends (day turns into night, roses fade and die, and spring turns to winter). Then, at the end, he states that the way to fight against inevitable death is to live a good life, so that your impact lasts longer than you do. He states, "Only a sweet and virtuous soul...lives."
So, if you are to take both sides of his poem, and work "carpe diem" into it, it can be applied. Carpe diem means "seize the day," and if we have the attitude that all days end and go away forever, shouldn't we be more keen on making the most out of each day that we have? If the end is coming, the time we have is more precious, so we should seize each moment, to make the most out of it. Then, if we take Herbert's words to heart and believe that living a virtuous life is the only way to cheat death in a way, we should be spending every single moment seizing upon opportunities each day to live virtuously. So, seize the day because time is short, and seize the day to live virtuously, in order to make a greater impact.
Those are just a couple ideas; I hope they help!