I have a fence line behind my house that forsythia struggles growing on. Is it because there's not much sun there, or because of the pine trees overhead? I know that the trees are using the acids in the ground. Looks like not enough sun to me. Trying to block sight from the cemetary back there. What would be a good alternative? Utility lines are above too, twenty foot above. So tree's seem too tall unless there's a good option. Like to find a plant similar to the forsythia in growth speed, color and hardiness. Any ideas?