Iris unguicularis hardiness
James Waddick (Fri, 24 Feb 2012 20:43:16 PST)

cretensis, is more cold-hardy than the North African I. unguicularis.

Dear Jane and Jutta,

My unguiculares is blooming again. We've had a mild winter
and buds were just opening. Then we went to 5 degrees F and the
flowers froze, but 10 days later it is blooming again.

Iris cretensis (from Jane) looks unfazed under the same
weather as does I lazica, also related. Neither of these two have
bloomed yet.

Last year we went to -12 F and stayed below freezing for
weeks. I unguiculares and lazica were well mulched, but both bloomed.
I did not have I cretensis in the ground then.

Obviously they are quite hardy given a number of specific
growing conditions. I think like many plants that might be 'tricky'
to grow in some climates, there is a matter of finding the right
drainage, soil conditions, mulch, exposure, etc. I have lost I
unguiculares and I lazica in other sites over the years.

For those of you not totally familiar with I unguiculares, it
has a surprisingly large flower and blooms at or before the
reticulatas here in Kansas City. I am very happy to grow this form
that I got from Wildwood Gardens in OR http://www.wildwoodgardens.net/

Best Jim W.

--
Dr. James W. Waddick
8871 NW Brostrom Rd.
Kansas City Missouri 64152-2711
USA
Ph. 816-746-1949
Zone 5 Record low -23F
Summer 100F +