Introduction
Many of Tokyo’s beloved Somei Yoshino cherry trees, planted during the country’s post-war economic boom in the 1960s, have now reached an advanced age. Their deteriorating condition has raised serious safety concerns among local authorities and residents, especially as the annual cherry blossom viewing season, known as hanami, draws large crowds to parks and greenways.
Recent Incidents and Statistics
On Thursday, two cherry trees collapsed in the capital. One fell at Kinuta Park in central Tokyo, damaging a fence. The other came down along the Chidorigafuchi promenade, narrowly missing the Imperial Palace moat. No injuries were reported in either event. The Kinuta Park tree stood 18 metres tall, with a diameter of 2.5 metres, and was estimated to be over 60 years old – among the oldest in the park. Earlier in March, another aged cherry tree at the same location fell and injured a passerby.
According to Masakazu Noguchi, a Tokyo metropolitan official responsible for public parks, 85 trees collapsed in the city’s parks last year, injuring three people. The majority of these were cherry trees.
Causes of Deterioration
Experts attribute the weakening of the trees to two main factors: natural aging and internal decay caused by fungal growth. Hiroyuki Wada, a certified tree doctor, noted that warning signs include a pronounced lean, holes in the trunk, or the presence of mushrooms at the base. He added that the risk increases significantly when rainwater accumulates inside the trunk after a downpour.
Wada also pointed to broader environmental changes. “Many of the trees we see in daily life were planted just after the war and are now 70 to 80 years old – they are growing weaker,” he said. “Extreme summer heat and prolonged dry seasons are taking a toll. I hope people will consider climate change through what is happening to the cherry trees, which are such a symbolic species.”
Official Responses and Public Concern
Following the March incidents, municipal officials conducted health inspections at Tokyo’s major parks ahead of the cherry blossom season. At Kinuta Park alone, over 800 cherry trees received preliminary checks. Several were cut down, and warning signs were placed near some trees. However, the tree that collapsed on Thursday had no such sign.
Noguchi acknowledged that current measures are largely temporary. “We have not yet taken fundamental steps such as replanting,” he said. “We urge visitors to remain cautious, because even after an inspection, we cannot guarantee complete safety.”
Tokyo assembly member Yutaka Kazama expressed concern on social media last month, stating that some cherry trees at Kinuta Park appeared dangerous due to exposed roots or obvious rot. He called for firm safety measures without rushing to fell the trees.
Regeneration Efforts and Public Sentiment
At Inokashira Park, one of Tokyo’s most popular hanami spots, authorities have already cut down dozens of aging cherry trees or their branches in recent years as part of a safety-focused regeneration plan. Some visitors have lamented on social media the empty spaces around the park’s pond, which was once seamlessly ringed by pink blossoms.
Tree doctor Wada stressed that an effective regeneration strategy is essential to preserving both the cherry trees and the scenic landscapes they create.
Despite the risks, many cherry blossom enthusiasts remain unwilling to miss the fleeting bloom, which typically peaks from late March to early April – coinciding with the start of Japan’s new school and business year.
“I am a little worried, but I think it will be fine if we stay away from the trunks,” said Lisa Suzuki, a visitor. Another guest, Akira Kamiyashiki, who came with his daughter despite safety concerns, noted: “Seeing the keep-off signs, I actually feel safe.”