Donald: The one year I had rust, the fall before I had received my first and only order from Maryotts. We had a mild winter, so all the green was not lost on their daylilies over that winter. However, and this is a biggee, in all fairness to Maryotts, the next spring I ordered from Carpenters in Texas , and two weeks after the arrival of their daylilies, one of them began spotting. So I think in all probability the rust came in on the Carpenter daylilies, but I couldn't swear to it as the Maryott daylilies also spotted pretty quickly......Our winters are erratic. Last winter was a warm one and had I had rust, I'm sure it would have overwintered and popped up this year. The winter after I got rust, by the grace of God, it was exceptionally cold - going down into the single digits, so any rust left over after I pitched all the obvious offenders, was killed. Because I can't count on our winters being cold enough I try to be extra careful about who I order from. I watch the weather over winter at the nurseries I patronize in Zones 7 -8 , and if they had a warm winter (again, like last year) I will not order from them that year. Also if they are northern nurseries I make sure that their daylilies are grown outside, not in a greenhouse where the rust could survive..........As to the heat stopping the spread of rust, I've heard the same thing myself, but my summer of rust we were well over 100 degrees for weeks and weeks and the rust never stopped. The blackspot on roses did, but not the rust. I would have to see factual data on this statement before I'd accept that as written in stone. .......I was lucky for many years not getting rust from the marginal zones, but rust has spread across the country now, more so then when I first started buying daylilies, so the odds of getting rust has increased. All I know is that I sure don't ever ever want it again........Maryl