We have a small garden full of manholes and drains. We want to plant something that will grow up in the corner of two walls 6 feet high and then give growth for a few feet above that to hide some very ugly buildings. Up to wall height it will be in permanent shade, but above that is full sunlight. The problem is the size of the trunk and the nature of the roots, because of the surrounding drains, it must maintain a slender trunk and its roots must be non-invasive. Does such a tree exist?
Certified GKH Gardening Expert
Unfortunately, I think you would be hard pressed to find a tree like that for the ground. Any tree will become root invasive if faced with a water shortage, even for one season. So one dry summer, and the tree would invade the pipes if they are nearby.
But, since you are in a small garden, I would recommend looking towards growing the trees in containers. Many trees will grow well in containers if you make sure they get the water and nutrients they need. You may also want to think about building a trellis and planting a vine. A climbing hydrangea would work in the conditions you describe as long as you have a trellis and, as a bonus, it could be planted in the ground.