Current planting policy for major roads in the Republic "takes very little account of the surrounding countryside and only serves to emphasise further the motorway `footprint' on the landscape", according to Irish Garden magazine.
A signed editorial by Gerry Daly, who presents RTE's weekly Ask about Gardening, says the policy seemed to be to "garden the motorways", often using non-native species, and it described this approach as "offensive".
It says the use of "alien species", densely planted, creates a strong contrast between motorway planting and the surrounding semi-wild countryside. There was also little cognisance taken of views across open country.
"Motorways slice through open countryside, and motorway planting should be of a piece with the landscape it adjoins," according to the magazine. In Northern Ireland, it was "generally less intensive" and therefore "better".
The editorial suggests that the dense planting of trees and shrubs along motorways south of the Border is driven by the fact that a percentage of each road budget is earmarked for landscaping and "must be spent on it".
It calls on the Department of the Environment and the National Roads Authority to reassess their policies with a view to protecting Ireland's distinctive landscapes. "Let us have planting by all means, but can it be done properly?"