Which plant characteristic is NOT typically associated with aesthetic desirability in trees?

Root depth is typically not associated with the aesthetic desirability of trees. While root depth is important for the overall health and stability of a tree, as well as for its interactions with soil and water, it does not directly contribute to the visual appeal of the tree. Aesthetically desirable characteristics are usually those that can be seen or appreciated visually, such as the presence of flowers, interesting growth habits, and unique exfoliating bark.

In contrast, flowers can enhance a tree's beauty during blooming seasons, growth habits can define the tree's overall shape and silhouette, and exfoliating bark adds textural interest and color variation to the trunk. These traits significantly influence the visual impact of a tree in landscapes and gardens. Root depth, on the other hand, operates below the surface and is more relevant to the tree’s functional aspects rather than its aesthetic qualities.