A natural woodland is composed of a multilayered tapestry of canopy and understory trees with a ground layer of shrubs and herbaceous plants. Trees of the same species are found at many different ages and irregular clusters, and do not necessarily have straight trunks and uniform heads. In fact, leaning and jagged trunks can often be the most interesting feature in the landscape.
Unfortunately, there is not enough space to create true self-sustaining woodlands on most residential properties. However, if the planting of site-appropriate native woodland species on the perimeters of suburban properties became commponplace, a series of continuous woodland corridors would be created, connecting existing isolated fragments of native forest badly in need of ecological interaction. The positive ecological impact of this would be quite significant, while the aesthetic advantages of suburban landscape in visual harmony with our native American forest would be easily apparent. Additonal privacy would be a bonus.

Larry Weaner–Ten Elements of Natural Design