Why Would Trees Be Problematic?
The main reason that is going to be problematic is that of proximity. It’s not just about the sunlight. The roots are going to be in the ground, and as they begin to intermingle, they are going to absorb more of the nutrients and water at a high rate of speed. This will minimize the number of nutrients that the trees and shrubs can get. They may become diminutive, or simply will begin to die. That’s why planting them far apart is highly recommended unless you are in the extremely rich soil, and you are also remembering to water on a regular basis.