For most of my roads that are an odd number of tiles, I outline them in bushes, but I skip one tile for each bush so the 12 bush limit doesn't kill any of them. I also put a flower in between them so it looks nicer. Oh, and you can't have any trees touching them either. Like if you want trees around your paths behind the bushes, skip another tile in between the bushes and the trees.
I'm pretty sure that tree stumps are part of the bush limit. So if you have one, you could only put a line of eleven bushes beside it without any dying.
I'm still working on mine but so far I've done some areas that are just bushes and then others that are a mixture so bushes, trees, flowers etc. That kind of thing.