The sakura front is as closely followed as the stock market and certainly more interesting, as there are more peaks. When will these most fickle of flowers bloom? How long will the fragile blossoms last? When should we be stand-by for hanami, the flower viewing?
The history of hanami is very old. The custom is first recorded for the Nara-period (8th c.), but interestingly the blossoms viewed then were not sakura, but plum blossoms (ume). The plum blossom which is strong enough to bloom in the cold season and has a very delicate fragrance was already in ancient China seen as a symbol for the perfect Confucian gentleman, the junzi.
The first time that "hanami" squarely means "cherry blossom viewing" instead of plum viewing, appears in Japans first novel, the Genji Monogatari from the early 11th c. The protagonist, Prince Genji was drunk with all sorts of blossoms, those on trees and those of the flesh.
Towards the end of the Second Month, the festival of the cherry blossoms took place in the Grand Hall. [...] It was a beautiful day. The sky was clear, birds were singing. [...]
Remembering how Genji had danced at the autumn excursion, the crown prince himself presented a sprig of blossoms for his cap and pressed him so hard to dance that he could not refuse. Though he danced only a very brief passage, the quiet waving of his sleeves as he came to the climax was incomparable. [...]
The festivities ended late in the night
But the real interest in sakura would come still later, in the great poetry compilation of the Shinkokinshu, commissioned by the retired mperor Gotoba in 1201. While its predessor, the 9th c. Kokinshu, still contains more poems about ume than sakura, in the Shinkokinshu the tables have been turned. Now countless poems were written praising the delicate flowers, in their ephemerality seen as a metaphor for life itself, luminous yet fleeting.
The medieval poet Saigyo (1118-1190) was one of the loudest laudators of sakura, and even wished to die under a blooming tree (a wish that was miraculously fulfilled). One of his most famous sakura poems goes:
switching my path
from the trail I marked last year
on Mt Yoshino
I go searching for blossoms
in directions I've never been
Yoshinoyama | kozo no shiori no | michi kaete | mada minu kata no | hana wo tazune
The sacred mountains of Yoshino were Saigyo's favorite haunt for sakura. This was the territory of the wandering, ascetic monks and Saigyo who did not belong to any fixed temple, was more or less one of them. Here he saw the yamazakura, the wild mountain cherry, which still graces the slopes of Mt Yoshino.
It was from this wild tree that later ornamental garden varieties were developed: our present sakura with double flowers, or the "weeping cherry trees" with their branches hanging down, or the late blooming varieties. Wandering through the mountains, Saigyo was drunk with sakura, as a sort of this-wordly Satori...
Modern hanami parties often are an excuse for getting drunk and although it can be fun to join the noisy crowds, it is better to find a secluded temple garden for more quiet but deeper enjoyment of sakura, the soul of Japan...
The quote from the Genji Monogatari is from the chapter The Festival of the Cherry Blossoms in the (online) translation by Edward Seidensticker.
See another translation of Saigyo's poem in 2001 Waka. It has also been translated by Burton Watson in Saigyo, Poems of a Mountain Home (Columbia 1991) - my translation follows that of Burton Watson closely, as there is usually no better way to put it than he does.