Siberian iris just happen to be one of my favorite iris plants.
They are easily grown, tough as nails, have few if any pest problems, survive in my cold zone 4 garden and bloom without flopping over.
What's not to like?
Siberian Iris are hardy down into USDA zone 3 and will bloom reliably there. They are usually hardy into USDA zone 2.
Zone 9 is the warm end so figure you can grow this plant almost anywhere except the hottest parts of the continent.
Siberian Iris - variety unknown
This iris prefers full sun but will thrive in light shade. The more heat you give it, the more shade it will tolerate. In other words, if you're growing in the South, it will take more shade than in the North.
Moderately fertile soils seem to produce the best flowering rather than heavily fertilized gardens.
In spring and summer it prefers a damp soil and this is why it makes an excellent bog or waterside plant. In the fall and winter however, it does want to be dry – standing water will kill it over the winter.
The plant is very easy to divide early in the spring or later in the fall. It is also relatively easy from seed and almost every flower will produce a seed pod after bloom.
Early summer is the height of the blooms. Early to mid-June in USDA zone 4.
One of the reasons I like this plant so much is that in my garden, I rarely had a problem with it. I occasionally will see thrips but that's about the extent of any problems.