I have a very tall potted brugmansia, over 6 feet. I moved it indoors into my sunroom, but now it has lost all the flowers and leaves and only the very tall stalk with the Y remains. Do I cut it back or leave it? The previous years I have cut it all the way down and I never get flowers in the summer, not until right before the outdoor growing season ends here in Minnesota. Is that wrong to cut it that far back?