Cherry Blossoms Science

I always thought sakura season was more of a touristy thing, but just realised how seriously Japanese themselves take cherry blossoms blossoming.

JMC’s Method for Forecasting Cherry Blossom Flowering Dates

The mechanism of cherry blossom flowering

The flowering and full bloom dates of cherry blossoms depend on the temperature patterns from autumn of the preceding year. The buds of cherry blossoms are formed during the summer of the preceding year. Before they flower, they must go through two processes: dormancy and growth.

Buds do not start growing as soon as they are formed; they first enter a period of dormancy. Dormancy allows the buds to survive the winter, with its cold weather and short days. This phenomenon is not exclusive to cherry trees. In temperate zones, many kinds of plant certain levels (between -5 and 15 degrees centigrade) during the autumn and winter period, trees awaken from their dormancy in anticipation of the approaching spring.

After breaking dormancy, the buds enter the growth stage, and grow as the temperatures increase to flowering. During this stage, the higher the temperature is, the better the growth rate will be.

During dormancy, buds do not show any visible development. However, once they enter the growth stage, they will grow increasingly large as the moment of flowering draws nearer. Eventually, their tips will turn a yellowish green color. Just before they start to flower, it will be possible to make out their petals.

– Source

And who knew there were so many types with subtle differences?

Types of Cherry Blossom Trees in Japan

Japan is home to around 100 native cherry blossom species that grow naturally, the most common and iconic being the Someiyoshino (Yoshino Cherry). Here are some popular cherry tree varieties you may come across during your visit to Japan.

• Someiyoshino (Yoshino Cherry): This classic cherry blossom, with delicate five-petalled flowers in a pale pink (almost white) hue, is widely planted in parks, gardens and along roads, creating a beautiful canopy when in full bloom.
• Yamazakura (Mountain Cherry): A wild species found in mountainous areas, Yamazakura also has five pale pink petals but produces both leaves and flowers at the same time, making it visually distinct from Yoshino Cherry.
• Yaezakura (Double Cherry Blossom): Known for its abundant layers of petals, ranging from 10 to 100, Yaezakura flowers come in a variety of shades from deep to light pink and stay on the tree longer than other varieties, making it a highlight of the cherry blossom season.
• Shidarezakura (Weeping Cherry): This variety resembles a willow tree with its cascading branches. Beloved for its poetic beauty, Shidarezakura creates long flowering tunnels and “blossom waterfalls”, providing a breathtaking experience for spring visitors.