by Jim Murrain
The best known of the Crested Iris is Iris tectorum. It is often referred to as the 'Japanese Roof Iris'. Of course we now know that it is not native to Japan nor does it grow on roofs unless forced to do so. It is one of the most common of the irises native to China.
It is very easily grown from seed or, thanks to its fairly large rhizomes, from divisions. Iris tectorum seeds have been available via the SIGNA (Species Iris Group of North America) Seed Exchange every year since I joined almost 25 years ago. It remains a very popular iris.
When grown from seed and a goodly number planted in your garden you can admire the many different shades of lavender and even white this iris manifests.
However we must take note of the crests! They can vary a lot on each seedling and somewhat on each fall! It can look almost like a simple beard or large jagged ridge to wild shapes that remind me of corals seen under water.
The amount of spotting or water marks on Iris tectorum can also be highly variable. It can have clear clean colors to heavily marked petals. The marks show predominantly on the falls but can manifest on the standards also.
This is one Iris where you can say "I have the blue, now I want the white". But the fun of growing a number from seed is to see the natural variations that can occur.
Even after being grown world wide for many years there are only a few named selections available, and they were primarily chosen for larger flowers or the amount of spotting. None of the odd forms have been chosen. I'm sure some of you would enjoy a monstrous form as seen here:
Iris tectorum has a huge range in its native land and can be grown in most places where people live. It will need a protected location in very cold climes and may benefit from growing in a pot under shade in warmer areas to help keep it cool when dormant. It is a fun iris in so many ways, and so easy even a child can grow it.
Most of the photos were taken in the garden of Rick Davis of Independence, Missouri and grown from SIGNA seed.