When surrounded only by manmade stuctures, without small plants or large trees, we feel depressed and out-of-place.

Both exterior and interior environments are much for uplifting when surrounded by plants.

Because it is a key part of our culture to want to control our environment, we often desire these plants to be highly controlled, by being strictly trimmed, and having clear deliniation between more natural planted areas and more strictly controlled manmade structures.

Placing plants close to windows on the outside can create the feeling of the buliding being set within a tropical paradise, while still creating a distinct boundary to achieve the border between naturalistic and mandmade.