I can't tell what else is around, but I know that bushes can't be placed at more than 12(?) consecutive bushes in a single line, so maybe you have too many lined up? There's also weird 'rules' about how many bushes/trees can be in a given area, but I'm not sure what the limit is, and also some towns just have dead spots. I tried forever to put a bush in front of my mayor's house but it wouldn't take for no discernible reason and I was advised by others it could just be a 'dead spot'.