Is this cedar apple rust?

[Frozentreehugger]

Yep , rust it’s like juniper herpes , you can treat it but it will always be in the trees system , applying copper fungicide can suppress that symptom through the year

I was not aware once it’s in a juniper . It is always there . I’m a oddball in the bonsai world . Until I got my yard collected shimpaku .I had very little interest in juniper . Other than common needle juniper . Plus being Canadian we have different rules regarding chemicals . My understanding sone if the best are hard to get . There is a 2 day course that gives you a licence . To increase what you can have . As for the rust . My cottage is west of my house . Basically just north of Kingston Ontario . ERC is native in the woods . I don’t think I have seen a mature tree ( taller Then 5 feet ) that is not infected ( galls visible ) but they seem healthy trees . There is 2 to 3 foot thick trunks on 30 foot trees .

 

[jandslegate]

Immunox is an effective treatment. Last year I had ACR on a couple small hawthorn. I cut off what I could without too much disfigurment and sprayed it with 50/50 peroxide and water. It worked but it was a small sampling.

The peroxide/water seems to have helped. How often did you apply? Cutting in the case of the older juniper isn't viable as I'll be left with essentially a bare trunk. Most of the areas are at pad junctions.

 

[penumbra]

It won't hurt to do it every few days.

 

[Frozentreehugger]

My understanding is the fungicide Ferbam. Is the most effective . Control for cedar apple rust . Health Canada has banned the sake or use if this product in Canada. I have no idea of availability elsewhere . But obviously safety measures need to be followed .

 

[James W.]

In wet weather, particularly while it is raining ^^^

This may or may not be the case, it depends on many factors. It can be devastating on apples. And you sure don't want to lose a branch to it on a bonsai you have been working on for years ^^^

By this time it is too late and it is producing spores ^^^

You know, it is whatever works for you. What is your comfort level? I am always concerned when I see it in my neck of the woods. I have two hawthorn that are half the size they were a year ago because I waited too long. I would prefer to listen to someone for whom it has caused a problem before I followed someone who thinks its not a big deal. This is my take, mileage may vary.

I apologize if I was unclear, I was commenting specifically on its affect on junipers, which was the OP's concern. On junipers it does not produce spores unless and until it produces fruiting bodies.
On apples, hawthorns, etc. the damage is done before you see yellowing leaves and lesions so treatment is most effective if started before local juniper trees begin to release spores. I treat all my crabapples with a systemic fungicide.

 

[Frozentreehugger]

I apologize if I was unclear, I was commenting specifically on its affect on junipers, which was the OP's concern. On junipers it does not produce spores unless and until it produces fruiting bodies.
On apples, hawthorns, etc. the damage is done before you see yellowing leaves and lesions so treatment is most effective if started before local juniper trees begin to release spores. I treat all my crabapples with a systemic fungicide.

Bingo exactly my point . Like you I have experienced the devastation to apple , pro active treatment regime . Is necessary . Dormant spray fall and spring multiple times , and fungicide . Borer sticky traps in June . Plus the choice one or the other . If I lived on the west coast that choice would most likely be juniper . Considering the wild tree possibilities . But in the north east it’s apple . And I’m venturing into service berry . Dormant sprayed the tree I’m going to collect this spring last fall .

 

[James W.]

Bingo exactly my point . Like you I have experienced the devastation to apple , pro active treatment regime . Is necessary . Dormant spray fall and spring multiple times , and fungicide . Borer sticky traps in June . Plus the choice one or the other . If I lived on the west coast that choice would most likely be juniper . Considering the wild tree possibilities . But in the north east it’s apple . And I’m venturing into service berry . Dormant sprayed the tree I’m going to collect this spring last fall .

You should not avoid junipers as bonsai because of cedar-apple rust. It is a minor problem and easily dealt with in junipers. I have never observed a gall on any of my juniper bonsai but if I did I would remove and treat it before it produced any spores. Galls have to be in their second spring before they produce spores and they would be obvious well before that.
Infections on my crabapples come from the thousands of ERC that grow within a mile of me. At some time I may decide that crabs will not work for me in this area but it has nothing to do with my juniper bonsai.

 

[Frozentreehugger]

You should not avoid junipers as bonsai because of cedar-apple rust. It is a minor problem and easily dealt with in junipers. I have never observed a gall on any of my juniper bonsai but if I did I would remove and treat it before it produced any spores. Galls have to be in their second spring before they produce spores and they would be obvious well before that.
Infections on my crabapples come from the thousands of ERC that grow within a mile of me. At some time I may decide that crabs will not work for me in this area but it has nothing to do with my juniper bonsai.

I did not say I avoid juniper . Just ERC fir there rust attraction . If I found a nice enough trunk I would must likely collect it and eventually replace the foliage with shimpaku .

 

[ERClover]

Hopping in to seek an ID of a crab ailment that I suspect could be rust as well. This little guy is the sole survivor of the “trees” I received for making a donation to the Arbor Day foundation (more like sticks with barely any roots). Only survivor that struck so it’s a bit sentimental in that way. Of course, you’ll know by my name I also love ERC and aside from the several large mature trees on my property I have a little guy I’m growing. There is a lot of conflicting information out there so I figured I’d seek the advice of those here. This crab absolutely exploded after an initial first flush at the apex and now has branches and foliage everywhere. The last week or 2 it has slowed down though and I’ve begun to see some dieback on leaves here and there, including some spotting that has me worried which I will picture. Some of this could be totally normal as I am new and getting my horticulture up to speed but I’d just like to take whatever preventative action I can to give these two the best chance of coexisting. Pictured are the fellas and close ups of some of the affected leaves.

 

[James W.]

Hopping in to seek an ID of a crab ailment that I suspect could be rust as well. This little guy is the sole survivor of the “trees” I received for making a donation to the Arbor Day foundation (more like sticks with barely any roots). Only survivor that struck so it’s a bit sentimental in that way. Of course, you’ll know by my name I also love ERC and aside from the several large mature trees on my property I have a little guy I’m growing. There is a lot of conflicting information out there so I figured I’d seek the advice of those here. This crab absolutely exploded after an initial first flush at the apex and now has branches and foliage everywhere. The last week or 2 it has slowed down though and I’ve begun to see some dieback on leaves here and there, including some spotting that has me worried which I will picture. Some of this could be totally normal as I am new and getting my horticulture up to speed but I’d just like to take whatever preventative action I can to give these two the best chance of coexisting. Pictured are the fellas and close ups of some of the affected leaves.

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Yep, rust.
At this point treatment is unlikely to be effective. Water and fertilize your trees, they most likely will recover.
Next year treat a month or two ago.

 

[ERClover]

Yep, rust.
At this point treatment is unlikely to be effective. Water and fertilize your trees, they most likely will recover.
Next year treat a month or two ago.

Thanks for the reply. I’ll try to give them the best shot possible. Knew it was a risk hopefully it won’t succumb to it.