This is a wonderful cross between the series of Pacific Coast iris (Californicae) and the 40-chromosome Siberian Iris. PCIs notoriously do not like to grow outside of their native range and are temperamental about getting transplanted. Sino-Siberian iris are finicky as well, only thriving in specific conditions. The specific goal of this cross is to get the unique flower characteristics of the PCIs onto a plant that will transplant well. The result is a complete success, at least in our garden. The range within which Cal-Sibs will be successful is still unknown, but I suspect it is much greater than either the PCI or Sino-Siberian.
We grow these in general garden conditions. Basically we plant them green side up, water occassionally, and fertilize if we happen to think about it. They thrive on a bit of neglect and reward us with amazing clumps of beautiful flowers.
We think Cal-Sibs are a premium plant for any perennial garden. Easy to grow with beautiful flowers, and foliage that gives structure to the garden for the entire growing season.
Give them a try. We think you will not regret it.
They do require acidic to neutral soil. Alkaline soil will kill them.
Hardy to zone 6, perhaps colder.
Full sun to bright shade.