The campaign was launched by the Posmrtna Pripomoć death grant society in cooperation with the Hrvatske Šume forest management company.
Petra Majdak Bijelić, who is in charge of the project, called the Tree of Memories, said that the response of citizens was very good and that they were constantly "adopting" memorial trees.
"We are very proud that a large number of citizens support afforestation with memorial trees. We want to give people the opportunity not to have to cut flowers or light candles but support the planting and growth of a new tree in memory of a person close to them," Majdak Bijelić said.
The campaign has a very pronounced ecological dimension. One tree reduces the amount of CO2 by 12 kilograms annually while producing oxygen for a family of four.
The project is organised and the tree planting financed by the Posmrtna Pripomoć death grant society, whose members will get a memorial tree free of charge, while non-members can take part in the project with a minimum contribution. The planting is done by Hrvatske Šume, which also provides the saplings.
The sessile oak is a very valuable tree species, it can grow up to 40 metres in height and up to three metres in width. In forests it is grown to the optimal maturity of 120 years, and it can live up to 1,000 years.
Hrvatske Šume said in a separate statement on 25 October that following the storms that hit Zagreb in July this year, it has been implementing a number of activities to renew forests, parks and public areas in the city and its environs.
In the coming period work is to be launched on renewing the insufficiently rejuvenated and storm-damaged areas as well as planting 21,000 trees, the company said.