I would be very grateful for recommendations for some tetraploid daylilies with rust-resistant foliage that stays nice all season.

Questions: I have several 'Just Plum Happy' clumps, and all are infected with rust. Do I need to worry about transmission of rust from this cultivar to others? Is there an effective treatment to get rid of rust?

Yes rust passes from plant to plant. But, do you know how you have rust in your area this early in the year? Are they new plants from somewhere else, and if not are you certain it is rust and not something else? I would normally expect rust not to usually survive the winter where you are but it was a rather mild winter. If you're not certain if it is rust, can you post a picture?

sooby said:Yes rust passes from plant to plant. But, do you know how you have rust in your area this early in the year? Are they new plants from somewhere else, and if not are you certain it is rust and not something else? I would normally expect rust not to usually survive the winter where you are but it was a rather mild winter. If you're not certain if it is rust, can you post a picture?

I observed the rust in this cultivar in past years, not this year. The foliage eventually has brown/yellow streaks that affect large areas of the foliage every year, and I have assumed it is rust, but maybe not. What else could it be? It has not been a problem with any cultivars other than 'Just Plum Happy'.

Rust has very distinct pustules that form and will come off on your hands if you rub the leaves. What you're describing almost sounds like summer dormancy.

You won't get rust on only one cultivar in the garden, it spreads on the wind and will affect others that are close enough - it sounds like what you have may be leaf streak. If you can't post a picture, these might help you compare

This first link has some pictures of leaf streak:
http://www.daylilies.org/ahs_d...

This one has pictures of rust and some other problems:
http://web.ncf.ca/ah748/FAQ.ht...

sooby said:You won't get rust on only one cultivar in the garden, it spreads on the wind and will affect others that are close enough - it sounds like what you have may be leaf streak. If you can't post a picture, these might help you compare

This first link has some pictures of leaf streak:
http://www.daylilies.org/ahs_d...

This one has pictures of rust and some other problems:
http://web.ncf.ca/ah748/FAQ.ht...

Thank you for these very helpful links, sooby. Leaf streak may be the problem. I don't have photos. My past approach was to hide 'Just Plum Happy' behind other plants in the garden. However, the flower scapes are not very tall, so the flowers tend to be hidden too.

Are there tetraploid daylily cultivars that are resistant to leaf streak?

Leaf streak does affect some cultivars more than others but the only extensive susceptibility list I can think of would be from a university dissertation/thesis on leaf streak quite a few years ago. I can check out which of two studies that I've seen have the list and post a link to it but if you're looking for daylilies hybridized in, say, the past ten or fifteen years then it won't help much. Let me know if you'd like to see the list.

sooby said:Leaf streak does affect some cultivars more than others but the only extensive susceptibility list I can think of would be from a university dissertation/thesis on leaf streak quite a few years ago. I can check out which of two studies that I've seen have the list and post a link to it but if you're looking for daylilies hybridized in, say, the past ten or fifteen years then it won't help much. Let me know if you'd like to see the list.

Sooby,

Yes, please, I would love to see the list.

You can download the thesis from this link, the leaf streak ratings are at the end in Appendix C:

https://etd.ohiolink.edu/ap/10...

I didn't see a note of ploidy though, so you'd need to look that up for any that seem interesting.

I should give the citation:
Whitten, K. (2005). Foliar diseases of daylilies caused by Puccinia hemerocallidis and Aureobasidium microstictum. (Electronic Thesis or Dissertation).

Sue - Thanks for that list. I am seeing leaf streak on a number if my registered and seedling leaves.

Thank you so much for the link, Sue. Ploidy is listed in Appendix A, so everything I need is there.