Chalyse, thanks for mentioning your poly performance in the sun; I am now inspired to make sure I move that one seedling (and also maybe some registered "polymerous" cultivars which aren't living up to their hype).
Sun is one of the things that I suspect might be a factor in poly percentage, though I do think water is very important. (Several years ago we had a fall and winter with very heavy rains and 100-year flooding in N. CA, and although we were nowhere near the flood zones, there was so much rain that parts of our yard were standing puddles or else sheer mud. That following bloom season there were poly blooms everywhere, including on daylilies that I had not seen poly blooms on either before or since.)
I have had 'Burmese Buddha' for many years, and it performed ~ 50% (if memory serves) polymerous at the old house, where although it had some shade, it overall got more sun than it does now. Here the poly % is much much lower. (The amount of water it gets might be lower too; that is hard to quantify.)
edited to thank Chalyse for inspiration
