Yellowing Juniper

[nip]

My shimpaku juniper appears to be headed downhill. It first started about 3 weeks ago. The inner branches/needles started yellowing. Looked like a typical case of spider mites, but the white paper test produced very few critters. I rinsed the tree well and sprayed with Malathion to kill the mites and the tree's condition did not worsen so I assumed I was ok. Fast forward a few weeks, I return home from a three day weekend and the tree is looking rough. Much of the interior is now yellowish brown. The outer branches remain very green and healthy looking, and the tree continues to grow and produces new shoots. I am hoping that the tree is simply shedding all of the damage it sustained during the original attack.
I do not see any other pests, such as scale. I do not own many junipers and this is my largest, so I want to ensure I'm not missing something.
Not sure if it matters, but the tree experienced heavy rainfall during the time I was away.
What else should I be checking for? The pot drains very well and I have been diligently allowing the pot to dry between watering (until the rain). Not sure what else to do other than keep a close eye on it.

 

[johng]

In my experience this is pretty typical of shimpaku. That said, this year has been a little worse, maybe a lot worse, than normal with my trees and trees of friends in my area. I spent much of the weekend pruning and pinching out the yellowed foliage from several of my junipers. If it proceeds as in years past, the trees will do just fine and continue to grow and develop new foliage.

I suspect this is just normal sloughing of old foliage and weak branches. The worst cases on my trees were all ones in which the foliage was overgrown.

I don't think you have anything to worry about!
John

 

[quietobserver]

Not that it helps anything but I'm having the same issue on a couple shimps. After weathering the mite onslaught they've looked like hell for a month now and have had an occassional new visitor (that causes panic from me)Frequent violent temperature changes haven't helped much either.

Good luck with yours!!

 

[Beng]

My juniper appears to be headed downhill. It first started about 3 weeks ago. The inner branches/needles started yellowing. Looked like a typical case of spider mites, but the white paper test produced very few critters. I rinsed the tree well and sprayed with Malathion to kill the mites and the tree's condition did not worsen so I assumed I was ok. Fast forward a few weeks, I return home from a three day weekend and the tree is looking rough. Much of the interior is now yellowish brown. The outer branches remain very green and healthy looking, and the tree continues to grow and produces new shoots. I am hoping that the tree is simply shedding all of the damage it sustained during the original attack.
I do not see any other pests, such as scale. I do not own many junipers and this is my largest, so I want to ensure I'm not missing something.
Not sure if it matters, but the tree experienced heavy rainfall during the time I was away.
What else should I be checking for? The pot drains very well and I have been diligently allowing the pot to dry between watering (until the rain). Not sure what else to do other than keep a close eye on it.

Is that a Rocky Mountain juniper from the west coast? If so I believe you may have some kind of fungal blight. If it was mites the tips would be getting yellow too.

 

[nip]

Is that a Rocky Mountain juniper from the west coast? If so I believe you may have some kind of fungal blight. If it was mites the tips would be getting yellow too.

Sorry, failed to mention it's a shimpaku.

 

[Brian Van Fleet]

I suspect this is just normal sloughing of old foliage and weak branches. The worst cases on my trees were all ones in which the foliage was overgrown.

I don't think you have anything to worry about!
John

Totally agree...

 

[dpowell]

I have to agree with John. I just spent 30 min cleaning out yellowing foliage out of one of my shimpakus. it does seem pretty bad this year, but as long as the tips are staying green then you should be good. I'm trying to be pro-active about cleaning them out in the hopes of getting some good back budding this year.

-Danny

In my experience this is pretty typical of shimpaku. That said, this year has been a little worse, maybe a lot worse, than normal with my trees and trees of friends in my area. I spent much of the weekend pruning and pinching out the yellowed foliage from several of my junipers. If it proceeds as in years past, the trees will do just fine and continue to grow and develop new foliage.

I suspect this is just normal sloughing of old foliage and weak branches. The worst cases on my trees were all ones in which the foliage was overgrown.

I don't think you have anything to worry about!
John

 

[nip]

It appears to be a combo of natural shedding, as mentioned by others, and my original hunch of mites. I happen to read Brent's (evergreengardenworks) article on spider mites and he mentions a red mite much smaller than the others and barely visible to the naked eye. I did paper test again, taking a closer look and noticed super tiny red specs that were not moving. I ran my finger across the paper and small red smears appeared, like streaks of blood. The little vampires were right under my nose the entire time, I need new glasses! These things were way smaller than my previous encounter with mites, but at least I feel better knowing the source of the problem. On the flipside, one of my maples got burned by the malathion because I didnt move it out of the sun. Malathion is some mean stuff.
Better maintenance of older/internal branches should help reduce the future mite attacks. I let this one get too bushy.

 

[Wee]

I don't mean to hijack this thread but my juniper seems to be doing the same thing....I do the white paper test atleast once a week and have never found what I thought was spider mites on this or any other tree until yesterday.....I did find one of the tiny little red mites on one of my Yapons. So I sprayed everything and that was when I noticed the juniper's inside foliage was yellowing and falling off. I have no idea what kind of juniper this becasue I collected it last July. Here are a few pics....I will follow this thread to see how the OP juniper responds.

Brian

 

[Dav4]

I don't mean to hijack this thread but my juniper seems to be doing the same thing....I do the white paper test atleast once a week and have never found what I thought was spider mites on this or any other tree until yesterday.....I did find one of the tiny little red mites on one of my Yapons. So I sprayed everything and that was when I noticed the juniper's inside foliage was yellowing and falling off. I have no idea what kind of juniper this becasue I collected it last July. Here are a few pics....I will follow this thread to see how the OP juniper responds.

Brian

This looks like normal needle shedding to me.

 

[Vance Wood]

Shimpakus have a blessing and a curse, dense growth on the outside and top of the tree chokes/shades out, the growth on the interior and bottom portions of the tree. If you do not thin out the vigorous growth to allow light into the interior of the tree this is what will happen.

 

[nip]

Brian,

Your yellowing looks much more like natural shedding based on a comparison with my trees. My yellowing happened within a matter of days and was getting worse pretty quickly, and I could see it starting to impact the overall health of the tree. It also occurred throughout the tree on older areas regardless of sun exposure, while yours appears to be deep within the dark/shaded areas of the tree. But if you already sprayed, you should be fine either way.
My tree is already looking better by the way.