Since the pond is mainly intended to be seen from the south, the harmony of the south border unifies the diverse planting on the north side of the pond. I have many photos of my garden on my webpage, Kirk's Garden. Espaliered trees and shrubs are a striking way to introduce pattern into a garden. An espalier is a tree or shrub trained in a vertical plane against a trellis, fence or wall. For more information about them, click on the word Espalier.
Tree trunks can also give a garden a rythmic pattern.
This pattern can be formal or naturalistic. An example of a formal pattern is an allee, which is a long straight path or drive bordered by evenly spaced rows of trees. Hornbeam and lime are the species most often used in pleaching. A natural grove of trees can be given a random pattern by selectively removing or planting trees. This this approach is a great way to control a grove of bamboo.