Sue: How informative - AND - easy to understand. Sometimes not all scientific data is.......I had rust one time about 4 years ago after foolishly ignoring advice to shy away from southern plants unless I wanted to spray (I don't and won't). What a surprise when it showed up. It took me a week or so to realize it wasn't my usual leaf streak affecting the leaves, but the much dreaded rust. Since I mostly grow daylilies in pots I had somewhat of an advantage of being able to get the worst offenders separated from the others. Unfortunately our famous Oklahoma wind made moving plants not a sure fired way of protecting the uninfected ones. The rust kept spreading. Finally in order to save something, I ended up pitching the worst offenders out (not for everyone I know). The marginal ones I striped off all visibly infected leaves (and kept up with it). Since rust spores are spread by water, I put them underneath the back porch to protect them from any water source - everything from rain, lawn sprinklers to morning dew. That helped quite a bit. Then I prayed we would have a bone chilling winter......When people say freezing temperatures I always think that they are thinking 32 or around there. That's too high to kill rust. I talked to hybridizers who conjectured that the temperature must drop down to 18 or lower and hold for several days in order to kill the rust. Fortunately we had a cold winter that year and indeed I haven't had a return of rust since then........One thing I want to add is that when buying from marginal zones 6b-8, a warm winter can make all the difference, particularly if they import new cultivars every year. I'm in zone 7A and many of my daylilies still have a lot of green on them as I type this - and we have had a couple of randomly scattered nights in the teens - but not many and not consecutively. If my daylilies had had rust last year and I shipped them out this next spring, with this mild winter we are having, I'd more then likely be shipping that rust right along with them. Last year by contrast this wasn't the case as it was continually cold long enough in zones 7a-7b to kill any rust they had. Just something to think about this year when you are ordering new plants.............Maryl
