For most people the vegetation of the city is for ornamentation. We like it because it is beautiful, pleasing, and aesthetic. The vegetation of the city gives us a feeling of well-being, a feeling that we are in harmony with our environment. Amid the engineering wonders of air-conditioned buildings, bridges, and roads, dominated by plastic, steel, and glass, city dwellers nurture living plants with loving care. Plants are grown in window-boxes, on balconies, on patios, and on rooftops. They are grown against the walls of buildings, in the foyers of buildings, and even in individual apartments and offices. In short, plants are grown wherever it is possible to do so.

One myth should be laid to rest. The city vegetation is not necessary to ensure a supply of oxygen. The supply of oxygen in the air is derived from the whole earth's photosynthetic activity including that of the oceans, which comprises three-fourths of the total area. Oxygen supply is not dependent upon a single collection or grouping of green plants such as those found in a city.

City dwellers spend a great deal of time and effort in growing city plants, often under hostile conditions. They do not make the effort in order to purify the air, but in order to purify their spirits.