On January 20 1948 the National Institute for the Protection of Natural Rarities of the People's Republic of Croatia passed a decision to declare the landscape area in Trsteno a protected natural rarity. Since October 27 1962 it has had the status of a protected natural object as a natural monument - a monument of garden architecture - an arboretum. Based on the aforementioned it’s entry in the Register of Protected Nature Objects at the Institute for Nature Protection was determined. Therefore, it is protected under two laws - the Protection and Preservation of Cultural Heritage Act and the Nature Protection Act.
Pursuant to the Nature Protection Act (National Gazette No. 80, 2013, Art. 235) the protection and management of the Arboretum continues to be carried out by the Croatian Academy of Sciences and Arts in accordance with the Croatian Academy of Sciences and Arts Act with appropriate application of the said Act.
On the 30th October 2017 the Directorate for the Protection of Cultural Heritage of the Ministry of Culture of the Republic of Croatia issued a decision by which the land estate of the Gučetić-Gozze family and the Arboretum have the status of a cultural property, all according to the Protection and Preservation of Cultural Heritage Act.
