Japanese Roof Iris

© Cindy Dyer. All rights reserved.

Nikon D850 / Nikkor 105mm micro

Japanese Roof iris

Japanese Roof iris, photographed at Green Spring Gardens

Nikon D850 / Nikkor 105mm micro

© Cindy Dyer. All rights reserved.

Japanese Roof Iris

Japanese Roof Iris (Iris tectorum), photographed at Green Spring Gardens

© Cindy Dyer. All rights reserved.

Japanese Roof Iris

The Japanese Roof Iris (Iris tectorum) is native to China. It was first discovered in the 1860s, growing in Japan on thatched roofs, hence the common name. Below is an excerpt from a newsletter article by Gerald Klingaman, former extension horticulturist for the University of Arkansas, Cooperative Extension Service:

This charming little plant became known as the Japanese roof iris because that is where it was first observed by a Russian scientist, Carl Maximowicz (1827-1891). He spent three and a half years botanizing in Japan in the early 1860s and introduced numerous Japanese plants to Europe through his base in St. Petersburg.

In China, apparently the original home of the roof iris where it has been grown since at least seventh century, the plant grows on the ground like any sensible iris. But in Japan, it was found growing on the ridges of their thatched roofs.

Apparently this tradition started in Japan because of a decree by a Japanese emperor during a period of wartime when it became illegal to waste land growing flowers. All available land had to be used for rice or vegetables.

The main reason for growing the plant was not for its flowers, but for a white powder that was made by grinding the roots. The makeup used to create the white faces of the Geisha girls was made from the rhizomes. So, the plants moved from the garden to the roofs where it remained until being “discovered” by science.

This evergreen perennial is hardy to zone 5 and flowers from April to May. The 4-inch wide lavender flowers (‘Alba’ is the white cultivar) bloom for about two weeks. Growing just 12-14 inches tall, the Japanese root iris has a spreading, rhizomatous habit common to most irises. Also known as Wall Iris, the plants grow as well in partial shade as they do in full sun, but they perform best in dappled shade. Great for use in front of a border and in rock gardens, they prefer soil that is high in organic matter. Seeds can be collected in late summer and directly sown into the garden.

I photographed this beautiful flower on a shady walking trail in Garvan Woodland Gardens in Hot Springs, Arkansas last week. Garvan Woodland Gardens is a 210-acre wooded peninsula on Lake Hamilton. The Gardens were the vision of founder and benefactress, Verna Cook Garvan, who donated her property under a trust agreement to the University of Arkansas School of Architecture in 1985.

© Cindy Dyer. All rights reserved.