Leaf curl on Azalea

bwaynef

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Has anyone experienced the leaves of azalea curling length-wise AND UPWARD? I've seen references to azalea leaf curl caused by a particular pathogen that has them hanging limp and curling downward.

Full-disclosure, I've recently found some fungal issues on junipers not far from this azalea, and a chinese elm is being munched by something I've yet to catch. I noticed the curling after 2-3 days pretty consistent rain. After a day of drying out, and the pot being tilted, it doesn't seem to be any WORSE. I may've just imagined that it looks better, but quick to concede that any improvement would be marginal at best. (Pics to follow.)
 

bwaynef

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Apologies for the clutter. Was two-branches-two-leavesed two years ago and fully wired. I let this one grow out all last year after removing wire. Was/am hopeful to rein it in this year, if I can get past this issue.
 

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fredman

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WoW that's a lot of curl. I've had some but not as much as that. I don't know what causes that, but something is definitely wrong there. Waiting eagerly for someone to identify the cause.
 

bwaynef

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Has it dried out at all, I mean before the rain perhaps? Leaf miner causes curl, but I've never seen it curl in that direction. And I don't see any spots or fungal markers... @Leo in N E Illinois - put on your cape!
I've been working from home for weeks now, ...and basically live for 11:30 when I get to get out of the recliner that's become my office and go visit with my trees. As such, they haven't been subjected to dry spells so far this season.
 

bwaynef

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I still haven’t found any insects besides a couple of ants on the soil surface on this tree. None of the lacebug on azaleas pictures and leaf curl pictures I can find on the net don’t look like what I’m seeing. That said, I’ve got a book I forgot about, _What’s wrong with my plant?(and how do I fix it?)_. See the attached picture.
After noticing this issue, and the issues mentioned on nearby plants, I sprayed Organocide 3-in-1, and among the variety of pests it treats, “psyllids” are listed.
 

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fredman

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I personally don't think it's a pest. Did you have drastic temp changes that could've affected them?
 

AJL

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Hard to tell from the photos but the curled leaves seem to be only on newer growth and also look like theyre slightly yellowed, which suggests to me some sort of physiological response.
Maybe caused by fluctuations in temperature / water/ chemical/fertiliser dosage?
 

bwaynef

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They're not discolored. You're just seeing the undersides of the curled leaves, which aren't as green as the tops.

I worded my initial post so as NOT to lead the conversation in a particular direction, but I can't ignore the fact that this happened after several days of rain.
 

Harunobu

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So the leaves didn't wilt and become crisp and die? Never saw this on an azalea. Bit odd that it seems to be connected to rain, but also there doesn't seem anything else wrong with the leaves or plant. You would kind of think that this curling mechanism is related or similar to those cultivar that naturally have curled leaves, like 'Rinpu'? It kind of looks different, but I never had a curled leaf cultivar myself. Things like turgor pressure inside the cells of the leaves of course are connected to moisture in the roots which is connected to leaves. Not sure what more to make of it, but keep observant.

The fact that it happened to all new leaves on new growth suggests it is something plant-global or root-related. And not a pest in the leaves themselves.
 

Leo in N E Illinois

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I delayed answering, because I'm on the farm today, and my azalea with the exact same problem is home in Illinois.

My 'Hoshi no Kagayaki' has the same problem. I have 10 other azalea, mostly Satsuki, do not have the problem at all. All my azalea get the same treatment. For the last 3 years the 'Hoshi no Kagayaki' had the problem. I repotted spring 2019, and thought it would fix the problem. New growth looked good into autumn. It got forgotten on the farm, it a cold snap that the rest of my azalea did not get. I normally let them get a frost, but this one got near zero (-18 C). This spring all flower buds are dead, and leaf curl is back with a vengeance. Signs of new growth says it ain't dead yet. The cold alone isn't the problem, as it already had the leaf curl issue. The repotting and new growth looked good for a while, but it came back strong over winter.

I think I'll try a systemic, just in case it is psyllids. One fear is it might be viral, which would explain stronger expression in older foliage or after a stressor, such as cold.

I try to wipe tools with 70% alcohol between trees to prevent tools from transferring plant viruses. But all my isopropyl alcohol has been repurposed for Covid19.

So frankly, I have no idea what the cause is. None of my other azalea have the problem. There are no signs of fungal issues. So I am confused. I'll let you know if I come up with a cure.

There are no cures if it indeed is a virus. I will keep it isolated to some degree, and will not propagate it.
 
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