The shrubs will be placed very near a Norway maple, at the base of a deck, which is about 3. 5 feet off the ground. The purpose of the shrub is to be decorative, but not necessarily with showy flowers. I want something that is non-invasive and accepts pruning. It is important that it can be kept neat. I live in zone 6 in the Boston area. Lowest winter temps have become unpredictable.