Hello all! I need your help. Three years ago I started gardening as a first-time homeowner. It has been so hard. Anyway, my whole yard is shaded including the area/"bed" under this huge oak tree. Apparently, periwinkle is supposed to be the best choice. It had already been there before we moved in but only thrives right around the tree trunk. For the past couple of years, I have planted more and more to no avail. Someone at the nursery told me to put down a soaker hose which I did mid-summer last year. I think it gets watered better from a sprinkler...maybe because I have cheap soaker hoes. So, do I try again this year by planting more but this time making sure it is watered all season--one way or another. The problem is that anytime I plant more periwinkle, I have to break up the underground roots of the vinca. Could it be that its not growing becuase I keep breaking up the roots to plant more? Or, should I not worry about it and continue planting more but this time making sure to keep it better tended this year? Last year I put a layer of top soil mixed with leaf grow on top but it looked nutrient-deprived in no time despite the fact that I fertilize. I just don't know what to do!!!!! Please help. Thanks!!!