Answer: This is really difficult. Most trees are spreading and will not give you that kind of height and remain so narrow unless they have an extremely columnar form. And when they grow so upright in such a small area, it can seem a bit intimidating to the person standing between them. However, you might find an upright arborvitae for the full sun locations and possibly you could use a PeeGee hydrangea in the part sun location. This is actually a summer flowering, large multistemmed shrub but can be trained as a tree and pruned to fit. You might also consider vines trained to trelliswork that fits each area. Your local professional nursery staff will probably have some other suggestions based on a more detailed understanding of what you are trying to achieve and the growing conditions where you are planting. Good luck with your project.
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