Aging of flowering cherry trees may change spring landscape in Japan

March 31, 2019

Aging of flowering cherry trees may change spring landscape in Japan

The Somei-yoshino species "sakura" flowering cherry trees are most commonly seen across Japan, and their five-petal pale pink flowers make Japanese delighted with the advent of the warm spring weather.
Most of these sakura trees were planted from the 1950s to the 1960s, on the river bank, around public parks and elsewhere, just after the end of the Pacific War. Then, they have continued to grow, keeping in step with Japan's rebirth from the ashes of the war, but many of them are becoming old, with their extended branches dying down and their blooming power waning overall.
The Somei-yoshino sakura trees, an easy-to-grow species, are a mixture of two different species--the Edohigan and Ooshima sakura trees. They were developed late in the Edo era around the middle of the 19th century.
They are spread through grafting, not seedling. This means that the Somei-yoshino sakura trees found across the country are mostly clones.
The life of carefully managed Somei-yoshino trees is said to be 100 years or longer, but otherwise, their life is usually believed to be 60 to 70 years.
The Somei-yoshino trees are more vulnerable to a bacterium-induced disease. These trees, when 30 to 40 years old, extend their branches widely horizontally, creating a huge umbrella shape. Those which are planted in urban areas are disliked these years, mainly because they make the visibility poor on the streets.
The Flower Association of Japan, a non-profit organization, recommends replacing aging Somei-yoshino trees with less taller, more disease-resistant species, rather than plating the same species of trees again when they are to be switched.
Some of the recommended species bloom smaller flowers compared to those of Somei-yoshino sakura trees.
Another problem is that the flower color of these sakura trees is different from that of Somei-yoshino trees. So, if these recommended sakura trees are planted at many places across Japan, the spring landscape in the country may change in the years ahead, some experts warn.
Somei-yoshino sakura trees begin to bloom late in March to early April, from southwestern Japan along the Japanese Archipelago to eastern and northeastern Japan. But some sakura trees, Somei-yoshino or other species, are going to be cut down, here and there in Japan, due to not just aging but also other reasons.
In March 1984, nine Somei-yoshino trees, about 50 years old, were about to be cut down, because of a road expansion project, in Hibaru, Fukuoka City, southwestern Japan. The first of the trees was felled on the start of the project as scheduled, but early in the morning on the next day, one resident found a piece of paper with a "waka" Japanese short poem written placed on one sakura tree's branch. That read,"Poor sakura trees! Please wait just for 20 days, so the remaining trees can be alive for their last bloom."
The addressee of the poem letter was "Mr. Chikuzen Sakura Tree Keeper," that alluded the city mayor. This incident led the mayor to reconsider the project, allowing the remaining eight trees all to survive.
The sender of the letter was unknown, but the sakura trees, now called the "Hibaru Sakura Trees," have continued to bloom pretty pink flowers since then to entertain local people every spring.