Need help diagnosing Daylily problems

I have more than a dozen Stella D'Oro and Happy Return daylilies in my landscaping. The plants are several years old and were moved 3 years ago to their present locations. Some are on the east side of the house while others are on the southwest and west sides of the house. All are in full sun or receive sun for most of the day. All have been blooming and I see new growth along the edges. I do have heavy clay soil and the areas were amended with topsoil prior to planting. The plants are also mulched with wood chips. I do have heavy clay soil that I amended with topsoil before planting the daylilies. I also clean up all of the dead leaves in late fall or early spring.

The plants had been doing well this spring and only since July have they looked bad. The old flower stems are dried and there are a number of leaves that are dead or yellowing with orange. I started to pull out the old flower stems today trying to clean up the plants and numerous green leaves broke off at the base. The base of the leaf is also yellowed with orange areas. There is no "foul" odor to the crowns. New flower stems are curled up bent. There are also orange areas near the tips of the leaves, although nothing that "rubs off." The yellowing on the leaves is on the edge rather than the center. All of my daylilies seem to be affected. I live in mid-Michigan and we have had quite a bit of rain this summer.

I did some research and leaf streak, rust, and crown rot could be potential causes. I am hesitant to employ any treatment though until I have a better idea of the cause. I have not yet dug up the crown to inspect the roots, although that is next on my list.

Thank you

Not promising that this is your answer, but -- a couple of years ago, Minnesota had a tough fall-winter-spring. The spring was really nasty - very cold and wet for an extended time. All the daylilies all over at least the southern half of the state had problems. Lots of yellowing early in the season. I looked carefully everywhere I drove, and it was all over the place. They mostly survived however, as far as I could tell, though flowering was reduced. Mine made it through the summer; but it was an unimpressive year.

A friend of mine who works at a nursery and has connections in the daylily industry questioned a grower about this late in the season, and was told that there is a disease that is pretty much omnipresent with daylilies, that gets a hold on them if conditions are overly challenging. Daylilies are normally quite vigorous; vigorous enough to overcome whatever this is. But a really nasty season can mean trouble for them, and that year (I think it was 2012) was ugly.

If this is your problem, your best bet is to keep them as clean as you can, removing diseased foliage; and beyond that, give them the best possible care: appropriate water, appropriate or maybe even a little extra fertilizer, etc, and next year should be better. Good luck!

Its natural for day lilies over time to look a little rough. One needs to constantly remove older leaves as well as flowers after they have finished blooming. They are very susceptible to rust. I have never seen the new flower stems curled up like that. I do not think the rust causes that. A general cleaning and removal of the diseased and dying leaves and flowers with 10-14 day applications of Chlorothalonil(sold often as Daconil) helps tremendously.

Chlorothalonil often features in lawn fungus treatment products. I haven't read anything about it for maybe 20 years, but way back then, I used it to treat disease problems on spruce trees, even though it was labeled for lawns, because the active ingredient was chlorothalonil. Certainly worth a try! And drobarr, next time my daylilies wake up with a croak - I'll try it. Thanks!

Chlorothalonil is a broad spectrum preventive fungicide that has been around for a very long time. It is labeled on just about everything...even vegetables, ornamentals, flowers, and you are right lawns. Several companies sell the product as it is off patent and it has many different names. Please read the label because the rates can vary quite a bit depending on the plants you are applying and the formulation(concentration) you are using. Also applications need to begin prior to disease onset for best results and it needs to be reapplied on a 10-14 day basis when conditions for disease persist.

In the 1990's and even into the 2000's a lot of new narrower spectrum curative fungicides came onto the market. Because of their narrow spectrum, the number of diseases they can control are much fewer and also the potential for resistance is higher. Because of this, fungicides like chlorothalonil are making a comeback as an important base component of a fungicide program.

If you want to go organic, copper can be used as well as biological like Serenade or Neem oil. Biologicals need to be applied more frequently for best results.

I imagine it is getting cold at night up there in Perham. I will never forget those two years I spent in Fargo when I attended NDSU. brrrrrr!

What do you do with the foliage after the plant blooms? Do you leave the leaves? Or cut them off? I always had great daylilies when I left the foliage on until all signs of green vanished (then I promptly removed the old leaves, didn't allow them to overwinter...mulch instead) and divided them OFTEN , or else I just had a field of leaves. They'll turn brown and be really ugly if they aren't divided often. I found they were a LOT of work and maintenance for a really short season of blooming.

Well, karmatree, being you're in Florida, you might have different problems with leaving old foliage where it is, than I do. I think if I were you, I'd remove anything that's dead. It's just plain good cleaning practice, if there's any chance of that material harboring pests or diseases. Here in the almost-always-coldest area of the Lower 48, best practice is to leave the old leaves where they are until spring, because they form a protective mulch for the crown of the plant. Insects and diseases aren't an issue during the dormant period, because of the deep cold.

There are some great new daylilies that bloom for more extended periods of time (both in terms of how long each flower lasts, and length of blooming season), and that repeat bloom. Those that repeat are often advertised for that particular feature; and it's worthwhile to be on the lookout for "high bud count." As lovely as many of the older cultivars are, if your garden needs to be high-performance for a larger part of the year, you might want to look into replacing some of the older ones with the new developments. I've certainly observed *significantly* extended seasons - up to two weeks longer, and with repeats later on - with some of the new introductions.

No no, this was when I lived in northern Virginia....I would braid the leaves in the fall when they were still green, then remove the braids when they turned brown. I don't grow them down here...no room! :)

That braiding the leaves thing - that's interesting to me. My late husband was from north London (UK), and said they used to braid the daffodil leaves, so as to save them, but (I think) not have them look quite so untidy. At least -- I think that was the point. Right?

But to me it seems like it sort of defeats the purpose of leaving the leaves at all. If the leaves are pressed against one another, they're not getting light, at least to the covered parts; so they're not feeding the plant below the ground, right? It would be like having a caterpillar eat the leaves. What's not there is not productive.

Still, it must be enough, or there wouldn't be so many people who do it.

Anyway. If anyone can explain this practice, I would appreciate it. It's interesting, and I think about it every spring when I urge my perennials to grow faster while the daffodils are starting to lay down.

Well, you are right on both counts. It was for tidiness...it made it much easier to rake fall leaves around the big braids...and it was better than removing them completely, but not as good as just leaving them alone. Probably much better to leave them be, naturally...but it was a compromise I guess!