Hydrangea is a popular flower often seen in “tsuyu” (rainy period in early summer). The plant is native to southern and eastern Asia, where approximately 50 species exist.

The Japanese origin specie, hydrangea macrophylla is basically blue, while it had been improved into various colors and larger flowerheads after introduced to Europe in the late 18th century. Improvement was mostly done by French plant breeders, and the flower has gained great popularity. Potted hydrangea is now a symbol of Mother’s Day in France. Just like ukiyo-e (Japanese wood block print), its beauty was firstly discovered by Europeans, and the flower returned home in triumph.

The color of hydrangea changes depending on the pH of the soil. On acidic soils (pH 5.5 and lower), flower is blue due to aluminum, and on neutral to alkaline soil (pH 6.5 and higher) which is common in Europe, the flower turns into pink. Between pH 5.5 and pH 6.5, the flowers will be purple or a mixture of blue and pink. The color also alters during its bloom.

In the old days, unstable temperature fluctuation and high humidity of “tsuyu”, as well as inadequate medical treatment caused many people to die of the plague. Since hydrangea was often found at temples where those people were buried, a sad image as “flowers for lost lives” used to accompany the flower.

Nowadays, hydrangea is loved by the Japanese people as its brilliant colors are refreshing in the gloomy rainy period. There are so-called “ajisai-dera” (hydrangea temple) all over the country. Meigetsu-in (Kamakura), Gokuraku-ji (Shizuoka),Sanzen-in and Mimuro-ji (Kyoto) are famous ones, while Hase-dera (Kamakura) is known for its “Hydrangea Pathways".