Does it serve a greater purpose than a bow where it is?
I think that's the whole point here. You can't ever know if it serves a greater purpose, because it could have sentimental value. You don't know who planted it, why it was planted, how important it is.... And if you don't know, and it isn't yours to decide, you leave the damn thing alone. Otherwise it's simply theft for selfish reasons. Nothing more, nothing less. You can justify it until the cows come home, using whatever analogy or "logic" you can think of, but you're still taking something that doesn't belong to you because you think it's worth more to you.
If somebody breaks into your house and walks off with your TV, they can say "I'd watch it more than you did" or "I needed a gift to give to my poorly wife who lost half her face in a freak rowing accident" but that doesn't give them the right to take it from you.