For me, plants represent the start of something, whether it be positive or negative, desired or not. To me they are a reminder that there can be beauty even in dark moments, like thornbushes with rose blooms. And they also remind me that there will always be new beginnings and second chances.
I also love the individual symbolism of specific flowers. For example, the Black-eyed Susan represents justice, and the hollyhock represents ambition. Researching these hidden meanings is a hobby of mine.