I have a "hedge" along the South side of my house. There are alternating red stick dogwood bushes, and regular (I think) dogwoods. Last fall I cut them back, but since I don't know what I'm doing, I'm not sure it worked out. How far back can I cut them? They were very leggy, and I want them to get new growth from the ground, not from the ends of the branches. Is it too late this year?