Daylilies forum: Daylily Rust

Views: 2092, Replies: 5 » Jump to the end
Name: John Bales
Lewisville, AR (Zone 8a)
Region: Arkansas Cat Lover Daylilies Enjoys or suffers hot summers
Dec 2, 2016 3:01 PM CST
This week has been a bummer in several different ways but the final blow was finally identifying that what I suspected was daylily rust was indeed the problem (the spore stage has arrived). I'm been trying to rack my brain over how it could have spread so rapidly through flowerbeds on all sides of the house in one year. Between a wet spring and very humid summer, conditions have been ideal for fungal diseases. We've also had a lot of wind. The one thing I've considered that might be a method of spread is cats. We have six cats that love to play in the daylily beds, then move around the house and play in others. I can imagine spores on their coats hitching a ride from bed to bed.

Anyway, I've read plenty of material on rust. I've noticed some cultivars don't seem to be effected even with decimated plants right next to them so I need to start making note of them. I'm waiting for the dormant plants to die back and then will probably cut down all the diseased foliage and burn it, as well as all the dead foliage on the ground and the pine mulch (can replace with leaf mulch or pine straw). I know that there are some high priced fungicides that are supposed to be pretty good but I don't have that kind of money. Has anyone had much success with fungicides such as Mancozeb (Dithane) and Daconil? Since the fungus is at the spore stage, should I be spraying the plants now, even though the weather is in the 40s? I've also read that a solution of regular Dawn dishwashing liquid and water can be sprayed on plants with active rust as a contact kill. Anyone used that approach and again, should this be done in cool/cold weather? I've read that after that a systemic fungicide needs to be used and saw one of the Bayer 3-in-1 drench can be used on daylilies to treat rush but I would think that would be saved for the spring. Anyone have any feedback using this or can recommend some other systemic that I don't need to take out a bank loan Sighing! I appreciate any feedback. I have read quite a bit but would actually like to hear from people with experience in treating rust outbreak in their daylilies. Happy holidays everyone!
You can bury a lot of troubles digging in the dirt. ~Author Unknown
Name: Larry
Enterprise, Al. 36330 (Zone 8b)
Composter Daylilies Garden Photography Million Pollinator Garden Challenge Garden Ideas: Master Level Plant Identifier
Celebrating Gardening: 2015 Region: Alabama
Dec 2, 2016 3:37 PM CST
I have used Dawn dish detergent and other dish detergents, I never could say for sure if it actually did any good or some other factor was responsible when the rust actually diminished. I have also used Daconil and a few other fungicides with the same result. Was it a weather change, was it the fungicide? If the rust would react in an instantaneous manner it would be easy, but it always seems to take weeks to ever see any results. When I use Ammonia to kill snails I see instant results and I can say yes "Ammonia works to kill snails" but I can never be so sure with controlling rust.
I am always confused on things like "the rust dies when the leaves die", but how long does it survive in the mulch before the rust actually becomes unable to reinfect the planst?. "You should clean your tools after working with rusty plants" how long would rust live on a rake handle?
I just assume no chemical combination available at the local hardware or home improvement center works very well, or commercial growers would not have to resort to the expensive chemicals. So I am having to just try and determine how much rust is acceptable. I have to learn to just toss plants that show extreme rust, and accept those that only show limited rust. I have had more plants now for a few years, so soon I will be better able to make such choices. It has taken a few years to build up an inventory of plants to have enough to compare the tolerances of them.
I have reached my goal of having two hundred named cultivars, so now when I get rid of a plant due to rust I will have a space for a more rust resistant one as a replacement. The problem is I normally like to replace a plant with a newer cultivar with better performance characteristics, but the newer ones seldom have rust resistant ratings available. Still, even some of the plants that have a very good rust resistant score end up being pretty rusty in my garden, and others that have a poor rating sometimes show no rust at all. I also think that a plant might be rusty some years and not so much in other years, so it is not an easy decision to make most time. Then, there are some plants that just seem to get rust every year, so that will be an easy call to make. I currently have several in mind and if they show rust early in the spring next year they will be gone, even though the plants otherwise performs very well here.
Name: Peter
Allentown PA (Zone 6b)
Cat Lover Seed Starter Greenhouse Bee Lover Enjoys or suffers cold winters Pollen collector
Hybridizer Region: Pennsylvania Daylilies Vegetable Grower
Dec 2, 2016 4:24 PM CST
Dithane and daconil are contacts only. They will help. But you'll be spraying and spraying.

Green magic is another known contact that is inexpensive.

Your options are limited for "full removal" of rust... they include buying an expensive fungicide.
Name: Sue
Ontario, Canada (Zone 4a)
Daylilies Birds Enjoys or suffers cold winters Native Plants and Wildflowers Butterflies Annuals
Region: Canadian Keeps Horses Dog Lover Plant Identifier Garden Sages
Dec 2, 2016 5:21 PM CST
John, I think the fungicide in the Bayer 3 in 1 you mentioned is tebuconazole? I haven't looked at how the amount of active ingredient compares but there have been some studies on this and other fungicides for daylily rust that may be of interest. Tebuconazole seems to have worked well in this first one (the thesis also discusses the comparative costs of fungicide products towards the end):

You mentioned it as a drench, so this study might also be of interest:

As for UltraDawn dishwashing liquid, it was studied in this research:

Name: bron
NSW-Qld border Australia
Tay Daum in my subtropical garden!!
Dec 26, 2016 9:27 PM CST
John. I would not destroy your mulch. Sooby would know how long the spores can remain viable, but since they can only infect green parts of daylilies, why not dig some trenches or holes in your yard and bury it? It will already be great soil improver.

As one who lives in a (subtropical) climate perfect for rust, and probably a bit too hot for daylilies, I am pleased to say that removing infected leaves, or even the half that shows spores, has improved my plants by light years.
Name: Sue
Ontario, Canada (Zone 4a)
Daylilies Birds Enjoys or suffers cold winters Native Plants and Wildflowers Butterflies Annuals
Region: Canadian Keeps Horses Dog Lover Plant Identifier Garden Sages
Dec 27, 2016 5:28 AM CST
bron said:John. I would not destroy your mulch. Sooby would know how long the spores can remain viable.......

We know the "summer spores" can survive over a month in a lab but we don't know exactly how long they can survive outdoors where the environment is less conducive. But it's correct that they can't infect dead leaves. All they could do on a mulch for as long as they survive is to be blown or splashed back up onto green leaves. A mulch can also potentially keep more of the leaf bases green by protecting them from cold. The "winter spores" can survive the whole winter but cannot infect daylilies so not a concern unless one grows patrinia.

But reading through John's post again I'm wondering if we can see some pictures of the problem. John says he suspected he had rust but wasn't sure until the spore stage arrived. But the spore stage is the first thing one would see because the fungus itself is hidden inside the leaf. Also dry climates are not conducive to rust and John is in Arizona (is all of Arizona dry?) so it would be useful to confirm that rust is indeed the problem.

« Homepage
« Back to the top
« Forums List
« Daylilies forum
You must first create a username and login before you can reply to this thread.

Member Login:

[ Join now ]

Today's site banner is by chhari55 and is called "Rhodophiala"

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.