CHIEF Minister Katy Gallagher knocked back a proposal to plant 100 trees at the National Arboretum in memory of Raoul Wallenberg.
Ms Gallagher said it was one of an increasing number of such proposals being rejected.
The government does not want the arboretum - a place of education and recreation primarily created to conserve threatened flora species - becoming a memorial to a range of causes or individuals.
''The requests are becoming more frequent,'' Ms Gallagher said.
The ACT government did suggest a single ceremonial tree from Hungary, Sweden or Israel be planted in a forest at the arboretum, although the offer is yet to be taken up.
Israel's ambassador to Australia, Yuval Rotem, said he was disappointed the ACT government did not help.
Three embassies - Israel, Hungary and Sweden - unsuccessfully lobbied the ACT for a memorial and a street named after Mr Wallenberg. Eventually it was the Australian National University which agreed to host a memorial.
Ms Gallagher said groups involved in organ donation and diplomatic affairs had unsuccessfully asked for memorials.