Aesthetic functions of greenery in urban public space are examined using examples of cities in Slovakia, focusing on periods of changes of aesthetic principles. Greenery, tree alleys and public parks notably enter urban public space in the 19th century, with application of contemporary aesthetic principles. During the 20th century, bio-ecological values of vegetation rather than aesthetic functions move to the centre of interest. Today, lack of maintenance and conceptual planning are often reflected in poor aesthetic appeal of greenery.