Too much of a good scent? Hanoi curbs iconic trees

HANOI - Vietnam's capital Hanoi has launched a large-scale program to prune hundreds of its iconic blackboard trees and is considering relocating some after their distinctive fragrance proved too much for some residents.

Known in Vietnamese as hoa sua, meaning "milk flower", and also known as pulai and devil's tree elsewhere in Asia, blackboard trees can grow as tall as 60 meters (197 feet). The name reflects the traditional use of its wood for school items, as does its scientific name, Alstonia scholaris.

Blackboard trees have lined Hanoi's boulevards since they were introduced during French colonial rule in the late 19th century. They were later planted across the capital, and Hanoi now has about 14,400 of the trees, according to the city government.

At dusk, the trees release a pungent, sweet scent from their greenish-white flowers, peaking in September and October. Long associated with the arrival of autumn in Hanoi, they have inspired hit songs and poetry for decades.

But many of the city's nearly 9 million residents say the fragrance is overpowering.

"I simply cannot stand the smell," said Hanoi resident Nguyen Ha Long, 43, who said he stopped his evening runs because the scent gave him migraines.

Trimming 7% of trees

After years of complaints and smaller interventions, local authorities have launched their largest pruning campaign yet, stripping the flowers from about 7% of Hanoi's blackboard trees during a five-day blitz ending on Tuesday.

Officials also plan to relocate trees from streets where they are most heavily concentrated, adding to the impact of major public works projects underway in Hanoi that are rapidly reshaping the city's landscape as the ruling Communist Party chases ultra-fast economic growth.

Not everybody backs the move.

"I absolutely love the scent of blackboard trees. The stronger the fragrance, the more I love it," said Nguyen Thu Trang, 37, who lives on central Nguyen Du, a street lined with blackboard trees and which was also the setting of the best-selling novel "The Sorrow of War".

"My family has lived here for over 30 years, and we all love the scent. I feel deeply saddened seeing the city prune them," she added.

"The smell is not toxic," said Tran Cong Khanh, head of Vietnam's ethnomedicine research center, echoing views expressed by three other Vietnamese scientists interviewed by Reuters, who however recommend limiting concentrations in densely populated areas because the pollen, like that of other plants, can trigger allergic reactions.

The debate has been widely reported by local newspapers, despite public health rarely ranking among Vietnamese residents' top concerns.

By contrast, air pollution, which often makes Hanoi one of the world's most polluted cities during winter, has generally attracted less public attention. — Reuters