While landscaping around our home I've noticed several principles that seem pleasing to me. What follows is an attempt to seek explanation and perhaps reveal a bit about the workings of at least this human mind: (Potentially what is pleasing to me might be pleasing to others and reveal general principles about all nervous systems.)
We live in a house with a number of distinct rooms. When I landscaped, I found it comforting to place small hills, shrubs, and trees to create distinct
rooms in our yard. The road affronting our property is isolated by a tall cedar hedge; our driveway is separated from the rest of the yard by a banked mound topped by native shrubs and tall trees; the lawn that extends from our unedged bedroom deck is bordered by dividing groves of trees. There are passageways that connect each part of the yard, but each section has the sense of a bounded room.
Perhaps this comfort with enclosed rooms is a primitive need predating cave dwelling to when objects provided protection from the weather and attack by predators. Even today, walls may give a sense of detachment from distractions in the busy world (such as the nearby street).
Trees and Water
I've noted that when I was away from home for extended periods at locations with few trees and no bodies of water, I
missed both. Over the decades I have planted about a hundred trees in our yard. They seem to provide a comfort and a sense of
belonging. My early years were spent within a mile of Puget Sound. While we could not see the water from our home, the expansive view of water was common. In my teenage years our family lived in a water front home. Today I have desktop pictures of bodies of water on my computers, and feel comfortable when I get a glimpse of water in the distance.
This sense of comfort near water and trees may not be universal. It may be a matter of comfort with the surroundings of one's youth. But there may be some residual comfort that continues from where our distance ancestors dwelt. Trees and water seem to be two ingredients of landscaping that are comforting to many.
Once an architect told me that he insisted on windows in his building designs because humans had a need to periodically
rest their eye muscles by looking at distant views with essentially infinite focus. I have noticed that my lawn
rooms which have openings that provide distance views are most satisfying. And I felt particular distress when buildings were constructed that blocked views from walkways and streets I often transversed. A distance view of a mountain, plain, or body of water seems particularly desirable.