Post a reply

Image
Jan 12, 2016 10:11 AM CST
Thread OP
Name: Karen
Southeast PA (Zone 6b)
Celebrating Gardening: 2015
Should I worry about rust presence buying daylilies from southern vendors? How to prevent it from entering my garden? What precautions should I take? A lot places note that they have a regular spray program. Does that mean that their plants are free of rust?
Image
Jan 12, 2016 10:28 AM CST
Name: Sue
Ontario, Canada (Zone 4b)
Annuals Native Plants and Wildflowers Keeps Horses Dog Lover Daylilies Region: Canadian
Butterflies Birds Enjoys or suffers cold winters Garden Sages Plant Identifier
No, a spray program doesn't mean plants are free of rust. If you're concerned you can isolate new plants as far as possible from your existing plantings for a growing season so that if they get rust it will not spread as quickly. You should try not to have the new plants where the prevailing wind will blow from them to the existing plants if possible. A little more drastic is this procedure:

http://web.ncf.ca/ah748/newpla...

However, in your zone rust would most likely not survive through a winter, especially if all foliage is killed back to the ground on all daylilies and you do not winter mulch. If the foliage isn't typically all killed back in winter then there may be a risk in some years. We usually consider Zone 7 to be borderline for daylily rust survival but winters differ.
Image
Jan 12, 2016 11:30 AM CST
Thread OP
Name: Karen
Southeast PA (Zone 6b)
Celebrating Gardening: 2015
Thank You! Sue! Will soaking the plant in a diluted bleach solution kill the rust spores?
Image
Jan 12, 2016 12:14 PM CST
Name: Sue
Ontario, Canada (Zone 4b)
Annuals Native Plants and Wildflowers Keeps Horses Dog Lover Daylilies Region: Canadian
Butterflies Birds Enjoys or suffers cold winters Garden Sages Plant Identifier
It may kill the spores that it contacts, but it may not contact any that have fallen down deep between the leaves. It will also not kill the body of the fungus inside the leaves if there is a pre-existing infection that hasn't yet produced spores on the outside. Too strong a solution and/or too long a soak can damage the plants. I haven't tested this so maybe someone who does this routinely can comment. I have tested dropping diluted bleach on a pustule and it appeared to work but another pustule later erupted right beside it.
Image
Jan 12, 2016 12:35 PM CST
Name: Gale
CentralWa (Zone 6a)
Karen, I have seen others here suggest fall orders from states that have rust. That should limit the time rust would have to spread, before winter kills it.

Gale
Image
Jan 12, 2016 3:23 PM CST
Thread OP
Name: Karen
Southeast PA (Zone 6b)
Celebrating Gardening: 2015
Thanks, Gale! That is a great idea!
Image
Jan 13, 2016 8:41 AM CST
Name: Pat Strong
Stone Mountain (Zone 8a)
Birds Orchids Irises Hummingbirder Houseplants Region: Georgia
Dragonflies Daylilies Dahlias Cut Flowers Garden Photography Butterflies
Karen, I got rust from a California grower for the first time this summer. I've never gotten rust from a southern grower, but I'm fairly new to the daylily party. When I received the plants from California, I potted them up for about six weeks and there was no signs of rust what so ever. They were big, healthy and growing well. I later planted them in a small bed in my back yard and within a couple of weeks the rust exploded...infected nearly every plant in that bed. I removed as much of the rusty foliage as possible, but I didn't spray with anything. It looks like the few below freezing days have gotten rid of it completely. December was extremely warm in my area, but the last week has given us some winter like weather. I will see what happens in the spring.
Image
Jan 13, 2016 8:55 AM CST
Name: Sue
Ontario, Canada (Zone 4b)
Annuals Native Plants and Wildflowers Keeps Horses Dog Lover Daylilies Region: Canadian
Butterflies Birds Enjoys or suffers cold winters Garden Sages Plant Identifier
We know from a study that rust can be "latent" (not show any visible signs) for at least seven weeks after being exposed to spores, even though under ideal conditions it can appear within ten days or so, which is why I suggested above isolating new plants for a growing season to be on the safe side. I hope the freezing days have got rid of it for you, Pat - preferably it should have got cold enough to kill all the daylily leaves to the ground, otherwise there's a risk of the mycelium surviving inside them to erupt in pustules later on.
Image
Jan 13, 2016 12:28 PM CST
Name: Pat Strong
Stone Mountain (Zone 8a)
Birds Orchids Irises Hummingbirder Houseplants Region: Georgia
Dragonflies Daylilies Dahlias Cut Flowers Garden Photography Butterflies
Thanks Sue for that tidbit....if I had only kept them potted for a couple of weeks longer, the rust would have shown up and I could have isolated the plants. Lesson learned when getting new cultivars...isolate for the first season.

I clean the dead leaves and other debris from the beds every other day...hope this will help with any rust on the ground. Not sure how low the temps must get and for how long to kill the rust, but we should have a few more below freezing days ahead.
Image
Jan 13, 2016 1:17 PM CST
Thread OP
Name: Karen
Southeast PA (Zone 6b)
Celebrating Gardening: 2015
Pat, I hope the cold will kill all the rust spores for you. It sounds like if the foliage is frozen, the rust will die with it.

Let's just say I receive the new daylilies and plant them in the pots. After a week or two, I notice that they have rust. Besides isolating them, what else can I do to eliminate the rust from the plants? Do I strip off the foliage and spray it with fungicide? Will this kill the spores?
Image
Jan 13, 2016 4:11 PM CST
Name: Sue
Ontario, Canada (Zone 4b)
Annuals Native Plants and Wildflowers Keeps Horses Dog Lover Daylilies Region: Canadian
Butterflies Birds Enjoys or suffers cold winters Garden Sages Plant Identifier
There are two separate ways daylily rust can survive (actually three but the other requires patrinia plants). You have the body of the fungus, made up of strands called mycelium, which is the parasitic part of the fungus that "steals" the plant's nutrients as it lives inside the leaves where you can't see it. Then you have the visible spores that the mycelium produces on the outside of the leaves, which are asexual reproductive units. So to think of it in equivalent terms, the fungus is like a plant and the spores are like the plant seeds. Killing seeds doesn't kill a plant.

This is all a long way of saying that focusing on the spores is not enough. Yes you can kill spores on the outside with a contact fungicide as long as that fungicide can contact all the spores. That won't do anything to the fungus that is inside the leaves waiting to sporulate (produce spores). To go after the body of the fungus inside the leaves you would need a systemic fungicide but not all of those kill the spores on the outside. You can strip the leaves with or without fungicide treatment, the link I gave above (post #1030111) illustrates a method of doing this that others have used.

Freezing of the foliage to the point where the foliage dies will kill mycelium. Freezing that doesn't kill the leaves may not kill the mycelium.. It is possible that mycelium will be killed at a higher temperature than will kill the leaves but in research on some other rusts it was found that rust mycelium could survive as much cold as the leaves could. Since we don't know which category daylily rust comes in we might assume that if the leaves survive a freeze then so could the rust inside them. A daylily can have its leaves frozen on the top but still have living green leaves at the base, and daylily leaves can survive quite a few degrees of freezing in any case.

Daylily rust spores can be deep frozen in a lab at much colder temps than they would experience outdoors, and still remain capable of causing an infection. The spores are less robust in natural conditions outdoors but even assuming they are killed you still need for the fungal mycelium inside the leaves to be killed as well to get rid of the disease.
Image
Jan 13, 2016 7:01 PM CST
Thread OP
Name: Karen
Southeast PA (Zone 6b)
Celebrating Gardening: 2015
Thank You! so much, Sue! I did look over the link that you provided but the process looks to be very drastic. I really would like to see blooms on these new daylilies this year. Doing that process to the daylilies would probably weaken the plants so much that there would be no blooms.
Image
Jan 14, 2016 2:06 AM CST
Name: Maryl
Oklahoma (Zone 7a)
Cat Lover Daylilies Roses Container Gardener Plant Lover: Loves 'em all! Cactus and Succulents
Region: Oklahoma Enjoys or suffers hot summers
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
Last edited by Maryl Jan 15, 2016 3:14 AM Icon for preview
Image
Jan 14, 2016 6:29 AM CST
Name: Sue
Ontario, Canada (Zone 4b)
Annuals Native Plants and Wildflowers Keeps Horses Dog Lover Daylilies Region: Canadian
Butterflies Birds Enjoys or suffers cold winters Garden Sages Plant Identifier
I tip my hat to you. Yes, keeping the leaves dry prevents any spores on them from germinating because they need several hours of leaf wetness to do so (the number of hours required depending on temperature), and hopefully over time they'll lose viability although keeping plants dry won't stop an existing internal infection if the plant was shipped with it. Indeed spores can be spread from plant to plant by rain splash although airborne spores on the wind are the primary method.

You're certainly correct that light freezes are unlikely to kill daylily rust. I once tested this in my garden and even after -8C (17.6F) I found a daylily with living leaves that had survived sufficiently that they were able to be infected when I tested them.

Of course all bets are off if there are patrinia plants in the vicinity since that potentially enables the full rust life cycle to kick in, allowing the fungus to persist through extreme cold. Still no reports of that happening in North America though as far as I'm aware.
Image
Jan 17, 2016 6:50 PM CST
Name: Joy Wooldridge
Kalama, Wa. (Zone 8b)
Sunset Zone 6, Heat zone 4,
I was one of the first 300 contributors to the plant database! Photo Contest Winner 2021 Lilies Daylilies Organic Gardener Cat Lover
Birds Region: Pacific Northwest Garden Photography Bulbs Plant Lover: Loves 'em all! Container Gardener
I'm in zone 8, but my zone 8 is nothing like it is in the south. Years ago I got rust from a southern grown plant I received. Our winter was cold enough, in the 20's, to kill it. I've never seen it here again. Not even on the plant that had it. I would think your climate would kill it too. I no longer worry about buying plants from the south.
No two gardens are the same. No two days are the same in one garden. ~Hugh Johnson
Image
Jan 17, 2016 8:27 PM CST
Thread OP
Name: Karen
Southeast PA (Zone 6b)
Celebrating Gardening: 2015
It's just that I started a bunch of seedlings this year. All of these will be planted out this spring. Should there be a rust outbreak, I am afraid that my seedlings may be severely affected and die.
Image
Jan 18, 2016 3:45 AM CST
Name: Pat
Near McIntosh, Florida (Zone 9a)
kousa said:It's just that I started a bunch of seedlings this year. All of these will be planted out this spring. Should there be a rust outbreak, I am afraid that my seedlings may be severely affected and die.


While seedlings are less resistant to rust, probably not all (or any) would die from it.

I use Green Magic spray (4 oz to 1 gallon) and that works fine, and any new plant coming in that might be suspect
gets soaked for 2 minutes in this solution too.

On seedlings without a bunch of leaves even the 3 in 1 organic spray will slow rust down or even kill it off if spraying is kept up.

Bayer make a systemic spray that works fine too, and I sometimes use that in rotation.
Image
Jan 18, 2016 6:09 AM CST
Name: Sue
Ontario, Canada (Zone 4b)
Annuals Native Plants and Wildflowers Keeps Horses Dog Lover Daylilies Region: Canadian
Butterflies Birds Enjoys or suffers cold winters Garden Sages Plant Identifier
I agree with Pat that seedlings are unlikely to die from rust, although I haven't heard anybody say that seedlings are less resistant before. Is this from your personal observation, Pat?
Image
Jan 18, 2016 7:58 AM CST
Name: Becky
Sebastian, Florida (Zone 10a)
Celebrating Gardening: 2015 Daylilies Hummingbirder Butterflies Seed Starter Container Gardener
Charter ATP Member I was one of the first 300 contributors to the plant database! Garden Ideas: Master Level Lover of wildlife (Black bear badge) Birds Ponds
I've had many a seedling get rust and never lost any of them.
What lies behind us and what lies before us are tiny matters, compared to what lies within us.
Garden Rooms and Becky's Budget Garden
Image
Jan 18, 2016 9:43 AM CST
Thread OP
Name: Karen
Southeast PA (Zone 6b)
Celebrating Gardening: 2015
I thank you so much Pat, Sue, and Becky for sharing your knowledge and experience. This has been bothering me alot and I am so glad to be assured by all of your posts. For years, I have refrained from buying from the south due to this rust issue. I know enough now that I don't get so freaked out if the rust does appear. Many thanks.

You must first create a username and login before you can reply to this thread.
  • Started by: kousa
  • Replies: 47, views: 3,758
Member Login:

( No account? Join now! )