From various conversations I had with growers the one year I had rust, there is a theory out there that says that just freezing temperatures (32) are not enough. The temperature must be below 18 degrees for 2-3 days in order to kill the rust. In my case this proved to be true, and I had no rust the year following a rust outbreak after temperatures went down to that mark and held for 2 days (aside from other cold days that just weren't as low as 18)......Michele makes an excellent point too. As long as there is even an inch or so of green down near the crown of an infected dayliliy, the rust spores could conceivably over winter. I still isolated those daylilies that were heavily infected with rust that retained even a smidgeon of green over winter until another growing season elapsed. As it turned out there was no new rust on even those.....I think caution is always wise when bringing in any new daylily from anywhere, but the marginal southern zones (7b-8) may have experienced enough cold this year to have a good reduction in rust, at least in the early spring. Order and plant early would be my advice. This will lessen the risk of receiving rusty plants as the gardening year progresses......Maryl
