Thank you very much, Judy, for registering this wonderful plant, and giving us the story behind the registration, and a broader picture of regional performance. While 'Osterized' perhaps does not perform at its very best here, with respect to branching and budcount, I am nevertheless already looking forward to this season's bloom, which will begin in a little over 2 months from now.
Your post jogged me about the foliage; I can report that while the foliage does die back here, there always seems to be a few inches of it aboveground. (Even when I edited my original post, I got interrupted!)
That 'Osterized' rarely produces polymerous blooms here is not a slur on the plant, but rather part of an overall trend I have experienced with other polymerous daylilies (mostly diploids); they simply do not perform to as high a % of polymerous blooms in my zone 9 garden(s), as they have in their home garden.
What is the cause? I am sure there are many environmental reasons. I strongly believe that the amount of water the plant gets is a part of the picture, but by no means all of it. I suspect that the amount of sun/shade factors in, as well as day and nighttime temperatures when the blooms are forming. (Fwiw, I grow my 'Osterized' in a partly shaded raised bed, but as I said, it apparently also did not produce (m)any polys in Bill Maryott's full sun field.) One individual (sorry, I do not recall the name) who was on one of the paper poly Robins many years ago, felt that the amount of trace minerals in the soil was a factor.
I have personally witnessed one tetrapoloid cultivar, which was full of 4x4 poly blooms when I first saw it (in a pot) at a Sacramento area nursery, go to 1% poly blooms at best in my current garden, where it has bloomed for at least ten years. I have seen another tetraploid cultivar, which ran consistently around 50% poly in our last house, go to far less than that in our current house (where we have lived for fourteen years). In both cases, the plants in question are in different soil, and get more shade and probably less water than in their original situations; in the case of the first plant, there was also a move in excess of 100 miles southward. Similarly, I have a tet seedling which ran about 25% poly when I first removed it from my seedling bed and potted it. Most years since then, it has produced fewer polys than that (one year, 0%).
The difference? Different soil, life in a pot (probably drier), and the pot is in a
slightly shadier spot. Environmental conditions seem to be a tipping point for polymerous blooms, as well as other traits such as rebloom.
Finally, fwiw, it's 'Ms.' Polymerous, if you must assign a gender... otherwise 'Polymerous' or even (as they sometimes call me on the iris forum) 'Poly' is fine.
