终年郁郁芧荠下，借此风云际会时 This tells the place where and the time when a certain story happened. 终年郁郁芧xu4荠ji2下 Amid the forests of oak and shepherd's purse trees that are lush all the time in a year, ... 借此风云际会时 on the occasion of such a goden opportunity ... It isn't your fault not to understand these because this can be difficult to understand even to native Chinese speakers unless they're doing well in the native language. Actually I have to turn to a dictionary for help to get the meaning of 芧... So my suggestion is if you want to understand these, you should be able to understand a dictionary written for native speakers, and figure out the sentence structure. If you can't do these, personally I think you are trying to learn the good thing at the worng time.

请问你可以提供全篇诗歌吗，要联系上下文才知道哦。 can you provide the whole poem？