The practice of hanami is many centuries old. The custom is said to have started during the Nara Period (710–784) when the Chinese Tang Dynasty influenced Japan in many ways; one of which was the custom of enjoying flowers. Though it was ume blossoms that people admired in the beginning, by the Heian Period, sakura came to attract more attention. From then on, in tanka and haiku, “flowers” meant “sakura.”
Avoiding exposure to pollen is the best way to decrease allergic symptoms. Remain indoors in the morning and evening when outdoor pollen levels are highest. Wear face masks designed to filter out pollen if you must be outdoors.