Regarding iris planting times;
In my area, zone 6b, the traditional Siberian Iris planting time has
been the end of the year, September. I have followed this with quite
poor results. However, I have planted Siberians at the beginning of the
season (April) with excellent results... very well established
plants/root systems that overwintered extremely well.
It seems to me that logically, each agricultural zonal area will have
its own planting times that work better than applying a generalization
across the board. Indeed, your own garden may have its own micro-climate
which could change your requirements.
Breaking the traditional planting time rules to make it work...
Mississauga, Ontario Canada zone6b
Director, Canadian Iris Society
Newsletter Editor, Canadian Iris Society