Hanoi has stripped flowers from hundreds of its iconic blackboard trees and is weighing relocation plans after years of complaints that the autumn fragrance is simply too much for some residents.
Vietnam’s capital just finished its largest pruning push yet on the trees that line its streets and define its fall air. Local authorities spent five days cutting flowers from about 7% of the city’s blackboard trees, known locally as hoa sua, and say they plan to move some away from the densest blocks.
Reuters reported the campaign wrapped on a Tuesday, with photo dates placing the work in mid-October 2026. The city government puts the capital’s stock at about 14,400 of the trees. Nearly 9 million people live with the result.
The smell peaks in September and October. For some Hanoians, that peak is the season. For others, it is a reason to stay indoors.
Nguyen Ha Long, 43, said he stopped his evening runs because the fragrance brought on migraines.
He put it plainly.
"I simply cannot stand the smell,"
Nguyen Thu Trang, 37, lives on central Nguyen Du, a street thick with the trees and long tied to the novel “The Sorrow of War.” Her family has been there more than 30 years. She does not want the pruning.
"I absolutely love the scent of blackboard trees. The stronger the fragrance, the more I love it,"
She added that the whole household feels the same way.
"My family has lived here for over 30 years, and we all love the scent. I feel deeply saddened seeing the city prune them,"
That split is the whole fight. Same streets. Same trees. Opposite lives.
Blackboard trees can climb as high as 60 meters, or about 197 feet. Elsewhere in Asia they go by names such as pulai and devil’s tree. In Hanoi they arrived under French colonial rule in the late 19th century, first along boulevards and later across the capital.
They became part of the city’s identity. Now they sit inside a city the ruling Communist Party is racing to grow. Major public works are already reshaping Hanoi’s landscape. The pruning push lands in that same season of hard redesign, not a quiet garden project, but another official revise of what stays on the street.
Officials moved after years of complaints and smaller interventions. This blitz was larger. Flowers came off roughly 7% of the stock in five days. Authorities also say they will relocate trees from streets where the plantings are heaviest. The reporting does not name a full list of those streets beyond the concentration problem itself, or a final count of trees on the move.
Tran Cong Khanh, head of Vietnam’s ethnomedicine research centre, drew a clear line on safety.
"The smell is not toxic,"
Three other Vietnamese scientists interviewed for the same report echoed the point and still urged limits on heavy clusters in dense neighborhoods. Their concern was pollen and allergic reactions, not poison in the air. That is a practical warning, not a panic order. It also leaves city hall with a blunt choice: thin the rows, move the trees, or tell residents to live with a smell that has defined autumn for generations.
No official public-health ledger of allergy rates or measured scent levels appears in the available account. What does appear is a government deciding that “too much” is now a planning problem.
Hanoi did not invent neighborhood friction. It did turn years of gripes into a visible, city-scale response: crews in the trees, flowers stripped, relocation on the table.
Residents who love the scent watch a landmark get cut back. Residents who hate it get partial relief and a promise of fewer trees on the thickest blocks. Taxpayers and lawful city dwellers, as always, live with whatever the plan leaves behind, emptier canopies on some streets, the same migraines on others if the concentrations barely move.
Iconic plantings are easy to praise in tourism copy. They are harder to manage when nearly 9 million people share the sidewalk and the wind shifts in October.
A capital can pave, prune, and rebrand faster than it can settle what a street is supposed to smell like. When officials start relocating memory to quiet a complaint file, tradition becomes just another public-works line item.
