The new and equipped phenological observatory was opened on 23 May, 2014, at the Tivoli Park above the tennis courts. The observatory is equipped with information boards and tree markings, both also available in Braille.

In 2011, the City of Ljubljana and the Slovenian Environment Agency signed an agreement on collaboration in maintaining and promoting the international phenological park. It is one of the parks in the international network, initiated by the World Meteorological Organization. The phenological parks in Europe observe the phenological development of plants with same genetic foundation for accurate study of climate effects and plant development in various environments. These parks are planted with trees and bushes of a special characteristic – each plant is a descendant of one plant, grown in the parent garden in Germany.

Phenology is the study of periodic plant and animal life cycle events and how these are influenced by environmental factors. Phenological observations are exceptionally important in the study of atmosphere and biosphere effects; the perspective of observing and studying climate change and its effect on plant development. Phenology is important for farming and decisions on sowing, plant protection and irrigation. The field of medicine benefits from phenology, which announces blooming of allergenic plants, information important for people with pollen allergies. The coordination of phenological plant and animal life cycles affects the diversity of their environments, which is another aspect of phenological observation studies - the biotic diversity.

The international phenological observatory was founded in 1958 by the Hydrometeorological Institute of the Republic of Slovenia – today known as the Slovenian Environment Agency.