I've got three 1st year cascades that are growing nicely. The problem is that I didn't do my research and cut back all but one bine per plant. all three are about 6' tall now, and I know the root system is not growing as it should with only one bine. I know that I won't get a crop this year, so would it be good to clip the tops of these bines and hope more will shoot up? Will that work?