When I spray my roses I hit the daylilys too. The rusts are different as mike_rivers says, but the fungicide works on both. Hollyhock rust is also different and does not infect roses. I have found the semi-evergreen ones that lose their foliage for a short period don't get rust. The evergreens are the worst rusters. I have a few dormants even though they are not supposed to do well here and they have done ok so far and don't rust, either. I can only guess that the period of no foliage breaks the cycle. My neighbor handles daylily rust by cutting all the foliage off and putting it in the trash if any rust appears. The daylilys grow all new foliage rather quickly I think it affects rebloom for her though, she doesn't get a huge amount of rebloom.

Normally it is believed that daylily rust can not survive the northern winters, but if you give it a host plant, the Patrinia, the rust can survive and infect your daylilies again the following year. Rust is a bigger problem south where it can live on and infect entire gardens of daylily. In your case I guess it depends on how much you invest in your daylilies or if you have mail ordered any in the past season from southern growers. A lot of the more southern growers have to routine spray. I have a large selection of daylilies, some more expensive than others and most just older that are favorites and hard to replace, in my case, I would not chance it. I don't have Patrinia nor do any of my neighbors and I'm careful when I introduce new additions of daylilies to my garden. Most of my daylilies I have tried to purchase from daylily farms within a day or two trip from my locale. If you have a bunch of new introductions recently purchased from southern growers, you may not want to chance it. While you may chance a bit of rust one season up north, you would not want a repeat of it, which the host plant would/cou7ld provide you with. Rust on daylilies is not a pretty sight.

I probably shouldn't speak for your climate, because maybe it isn't quite the same as mine, but my point was that at least in my climate there is a time of year (summer) when the temperature is in the 90s or higher during the hottest part of the day and it barely gets below the 80s most nights. During that time, rust is mostly dormant. If your plants had a lot of rust in the spring, they will look bad in the summer because the leaves will die back uglier in the heat than they would if they didn't have rust. Then there is a time of year (spring/fall) when the temperatures range through the 60s and 70s most of the time, even though the high temperature might be higher. This is when rust loves to grow and spread. And there is a time of year (winter) when the temperatures are below 60 overnight and sometimes during the day. Again, rust will slow down, and your more dormant daylily foliage will die back. But you're right -- around here the winter is a mix of this and more moderate days. If you prevent rust during the spring and fall weather, new rust will not appear during the summer and winter weather. If you have rust during the spring and fall weather, it should mostly slow down during the summer and winter weather, although it may spread when the temperatures are unseasonably moderate. I'm going back over my notes, and this year I allowed rust to spread unchecked until mid-March in order to evaluate plants for hybridizing. Then I used Cabrio + chlorothalonil on the "public" plants in the front yard March 19, March 26, and April 11. I might have sprayed once in May and forgotten to record it. Over the summer, all the new foliage looked good and the old rusty foliage died back. Then this morning I sprayed again for the first time since spring because we had a cold front that brought daytime temperatures into the 70s with highs maybe hitting the 80s the last couple days. I have rust in my garden, and I control it as well as I feel I need to so that the front yard looks ok to me. To do this doesn't take a lot of work. And I allow it to spread naturally in my seedlings so that I can evaluate them for rust resistance. Nate

The first time an article about rust appeared in the AHS Journal ( and that was the first year we'd heard about it on the e-mail robin from the big growers in Fl- the first year that some of them got it from somewhere in Central or South America, and it sounded BAD when those initial reports came in. I remember one man talking about digging up his entire garden.) People were panicking big time! The VERY day that Journal arrived with pictures of rust and how to recognize it, I found it in my garden. Talk about panic!! I went outside - it was probably about 95 degrees that day and I was so psyched out that I forgot to wear sunscreen and got a horrible sun burn.... but at any rate, I started cutting ALL of the foliage back in the garden and putting it in huge black trash bags and dipping my clippers in bleach solution between each plant. Ugh! I can remember cutting, sweating, and all the time tears were running down my face. I didn't stop until many hours later that night. I can't remember now if I got the whole garden cut back that night or not.Back then it was nearly 1000 cultivars, but the whole garden was cut back w/i 24 hours to about 3" of foliage tops and then the entire garden was sprayed with fungicide even though I'd only seen rust on about 3 plants. Ugh! The very next day I sent a leaf sample to the State Plant Pathologist in Richmond, VA for diagnosis. My garden was the second "official" case of rust that year in the State of VA. I had quite a few nice conversations with the State plant pathologist ( who strangely, turned out to be a former student of my mother's!)but in the intervening years, have learned that it really isn't a reason for that kind of panic. I did learn more than I really wanted to know about rust that first year in all those conversations with the state pathologist. I do spray, alternately using Heritage, Banner Baxx, Daconil, and various other fungicides during the season. However, I'm a lazy sprayer and rust has never overwintered here on the edge of zones 6/7. I continue to buy plants from the South and there's always the risk it will appear, but that is a risk I'm willing to take nowadays. Some years it shows up here - but usually not until September,long after peak bloom and visitors. This year, I have found it on one FL. plant but so far it hasn't spread. Have sprayed a couple of times since then. Am not about to get out and cut back the whole garden like I did all those years ago. When was that - about 2003?