The pyrethrum is a white, perennial flower with an average diameter of
These flowers have been cultivated since the beginning of the Taisho era
(1912 - 1925) for their mosquito-repelling properties. In its heyday, the pyrethrum used tobe grown
on more than 350 hectares of land and used to cover most of the island like a white carpet
but, with the popularization of chemical repellents, harvests were gradually
reduced. Nowadays, the pyrethrum is cultivated in three places for preservation
and as tourist attractions.
Innoshima General Affairs Industrial Promotion SectionTrade, Tourism and
|The Pyrethrum's Introduction in Japan
The pyrethrum was first introduced in Japan in the 19th year of the Meiji era (1886).
It's origin was the Dalmatian region of the Balkan Peninsula. Around 1875, an American who
came to visit the mandarin garden of Eiichiro Ueyama (founder of the Kincho company) proposed
the exchange of rare plants. The seeds of pyrethrums and seedlings of orange trees were thus
exchanged in 1886. Mr. Ueyama searched all over for the proper land to plant the pyrethrum; he
found it in Mukaishima-cho. The late Eiichiro Ueyama was enshrined in the "Pyrethrum
Shinto shrine", built in 1930, in Mukaishima-cho, where the pyrethrum was first planted. A
while later, the Australian consul in Japan at the time, Mr. Geolt Huurot, is said to have learned
of the pyrethrum's easy adaptation to conditions in Japan and thus gave seeds to the former
Ministry of Agriculture, which initiated cultivation in Wakayama Prefecture.
A White Carpet
Afterwards, the main regions of production shifted to Hokkaido
and the Seto inland sea region. In Hokkaido, production of pyrethrum flourished
from around 1920 to when World War II ended, in 1945. However, because
of the high acidity of the cultivated land, other crops did not do as well.
As for the cultivation method, called "veteran use," flowers
are picked from the branches after a waiting period of a few years. This
unfortunately leads to poor harvests and, with the postwar shortages, production
was changed to other crops.
After 1955, production decreased rapidly; the pyrethrum is hardly being
grown now in Hokkaido. As for the Seto inland sea region, cultivation started
in 1897 and the area dedicated to the pyrethrum increased rapidly. The
market was eventually expanded to China, Korea and the southern seas, to
say nothing of the United States, Germany, and Australia. At one time,
the pyrethrum became the single most important Japanese export and the
country was once the largest producer in the world. The peak of production
was reached between 1937 and 1952.
| Production briefly declined when Germany invented the first
synthetic pesticides, but the interruption of trade due to the First World
War renewed the demand for pyrethrum and caused prices to skyrocket.
At the time, the town of Shigei-cho, with all its pyrethrum fields, was
literally covered with a white carpet. As far as the eye could see, everything
was white fields of flowers, the pine-covered summit of Mt. Shirataki being
the sole exception. It is said that people even went to tiny Hosojima and
Kobosojima islands by boat to cultivate the flowers.
Area Dedicated to Pyrethrum Production in Innoshima
||350ha (210ha in Shigei-cho)
|1963 (Postwar Peek)
||37ha (34ha in Shigei-cho)
||20ha (Shigei Umagami Shinto shrine),
18.8ha (south side of the Flower Center), 3ha (Mt. Shirataki Flower Line observatory)
|Moving with the Flow of Time
With the end of World War I, synthetic pesticides were once more
introduced in Japan, driving prices down and forcing a reduction of production. After World
War II, the cultivation was drastically shifted to other crops to increase food production, and
the cultivation of pyrethrum decreased sharply from 1946. Production was again increased
from 1953 to 1964, as pyrethrum was used in the making of mosquito-repellent incense
and agricultural chemicals, but synthetic insecticides (like Pyrethrin) and the increase of
cheap, good quality extracts from Kenya (for better mosquito-repellent incenses) caused
the cultivation of pyrethrum to disappear almost entirely in 1972. It is in this region of the Seto
inland sea that cultivation lasted the longest, until national production stopped entirely.
Conditions allowing for good cultivation of pyrethrum in the Inland Sea region
1. Good natural drainage and low rainfall average during the flowering season
2. Spring and autumn, the best periods for nourishment, are fairly long, making the growth period shorter than the flowering period by comparison.
3. Meteorological conditions in winter are ideal for the differentiation of buds, allowing for abundant harvests.
4. The pyrethrum flowers bloom at the same time, allowing for easy and efficient harvests.
5. The soil is rather poor, with many places actually made of granite. However, the pyrethrum thrives even in these conditions, allowing for a larger profit margin than most other crops.
6. The pyrethrum is grown as part of a very advanced intercropping system (wheat, pyrethrum, blue yam and sweet potatoes)
|The people who preserve and grow the pyrethrum
| The pyrethrum is currently grown as a tourist attraction.
There are about 41.8 hectares of land dedicated to the white flowers in
Innoshima, with 20ha in Shigei-cho's Umagami, 18.8ha at the Flower Center's
south side area and 3ha at Mt. Shiratani's Flower Line observatory. Every
year, local television and newspaper crews come to cover the beginning
of the flowering season.
Mr. Tomio Murakami has long grown and protected the pyrethrum.
Pointing to his house, overlooking the fields, he says: “I can see
this field from my window. At this time of year, there are lots of people
who come to look at the flowers, take pictures, etc. It always makes me
so happy.” He pulls out weeds, scatters fertilizer and pesticide
and repairs the paths to make them stroller-friendly. He even went so far
as removing the trees and bushes at the top of the field and clear out
a space for people to take pictures. “I do most of the fertilizing
and weeding alone” he says. “It's more a hobby than work, really.
And so many people come from the suburbs to see the flowers” he adds
with a smile.