Sick Junipers

[MrFancyPlants]

All three of my junipers are looking rough this season. The Blau usually looks pretty bad coming out of winter but then has put on some healthy growth by now. I’m hoping I didn’t spread some fungus to the other two. The procumbans was cut back this spring and the Kishu was repotted. All are showing healthy new growth, but way too much brown for comfort:

 

[Deep Sea Diver]

Wondering about the winter care… were they sprayed with a fungicide? Also how were they wintered over?

cheers
DSD sends

 

[MrFancyPlants]

They were place on the ground in a box, but I didn’t mulch them in with raked leaves as I had in the past. I don’t think I gave them a winter treatment of copper this year. Maybe that is the problem?

 

[Deep Sea Diver]

Most likely both the winter over area and the copper / etc treatment.

Most Junipers I can think of in your area shouldn’t need much protection. Placing these mulched on the ground in an area sheltered from the prevailing winds/strong sunlight is good, yet there should be decent airflow/light for the tree otherwise.

Can’t think of a tree I don’t spray with copper twice or more during the winter, especially junipers, who are known to glom onto cedar apple rust. That said nana, especially have a certain amount of older foliage die back… not as much as yours though.

Here’s an example…a section of a juniper tree that was taken out of the pot after winter a couple months ago and put into the ground to strengthen/grow out. It was sprayed the past three winters.



cheers
DSD sends

 

[Dav4]

That damage reminds me of spider mites…

 

[Hartinez]

That damage reminds me of spider mites…

What @Dav4 said. My experience also.

 

[Deep Sea Diver]

Yep. Always possible, worth a good look see with a sheet of paper and or a magnifier!

Cheers
DSD sends

 

[vp999]

Do you have any crabapple or apple trees near by? All my junipers are suffering from this right now, its some kind of disease that only occurs when there's juniper and apple near by. Been spraying copper and the crabapples are recovering nicely and no more yellow spots on the leaves but the juniper will take longer.

 

[MrFancyPlants]

I know an Apple tree a few blocks away, but there are a lot of ornamental and wild prunus in the area.

 

[Dav4]

Do you have any crabapple or apple trees near by? All my junipers are suffering from this right now, its some kind of disease that only occurs when there's juniper and apple near by. Been spraying copper and the crabapples are recovering nicely and no more yellow spots on the leaves but the juniper will take longer.

Are you thinking of Cedar-Apple rust... https://www.fs.fed.us/wildflowers/plant-of-the-week/gymnosporangium_juniperi-virginianae.shtml I don't think that's whats going on here. I still vote mites https://neilsperry.com/2022/02/spider-mites-on-junipers/

 

[Paradox]

Yea I agree with Dave and Hartinez, looks alot like spider mites to me too

 

[MrFancyPlants]

I have some 3-1 rose spray.. do you think that will do the trick?

 

[vp999]

Are you thinking of Cedar-Apple rust... https://www.fs.fed.us/wildflowers/plant-of-the-week/gymnosporangium_juniperi-virginianae.shtml I don't think that's whats going on here. I still vote mites https://neilsperry.com/2022/02/spider-mites-on-junipers/

Yes I do Dave. Just a possibility though, and only if there’s apple trees near by.

 

[Wires_Guy_wires]

Apple cedar rust would be visible after spring, those fruiting bodies are hard to miss and they actually don't really damage the foliage itself; they burst out in between the needles or from the bark, but just a couple scales/needles will go yellow because of it.

I'm thinking spider mites, possibly water issues (soil too wet for a long time, or too dry for a while; symptoms are the same because they're caused by root death).

 

[orangeyeoman]

Most likely both the winter over area and the copper / etc treatment.

Most Junipers I can think of in your area shouldn’t need much protection. Placing these mulched on the ground in an area sheltered from the prevailing winds/strong sunlight is good, yet there should be decent airflow/light for the tree otherwise.

Can’t think of a tree I don’t spray with copper twice or more during the winter, especially junipers, who are known to glom onto cedar apple rust. That said nana, especially have a certain amount of older foliage die back… not as much as yours though.

Here’s an example…a section of a juniper tree that was taken out of the pot after winter a couple months ago and put into the ground to strengthen/grow out. It was sprayed the past three winters.

View attachment 444967

cheers
DSD sends

Newbie here. Do you have a particular copper treatment you recommend? I've been practicing on a bunch of junipers (Japanese, procumbens, etc), and would like to keep them alive past winter.

 

[MrFancyPlants]

Newbie here. Do you have a particular copper treatment you recommend? I've been practicing on a bunch of junipers (Japanese, procumbens, etc), and would like to keep them alive past winter.

I’ve used Bonide’s Mancozeb, which I guess is Zinc based, but Bonide makes a copper fungicide too.

 

[orangeyeoman]

I’ve used Bonide’s Mancozeb, which I guess is Zinc based, but Bonide makes a copper fungicide too.

Great. Thanks.

 

[ZombieNick]

I had a juniper get hit with spider mites hard this year and I learned a little about identifying them. First, the foliage turns "grey" where affected (before it browns), especially on the interior foliage. Not to be confused with the yellowing that lack of sunlight causes. Here is a picture of my affected tree to get an idea of what I mean. Notice the darker, duller foliage on the left branch compared to the healthy branch on the right (and I am not talking about the brighter new growth, I am talking about the interior color):


Second, you can take a piece of white paper and hold it under the foliage and give it a good shake. Then, rub your finger across the paper. If you see little gut trails you have mites, if it is clean you are good. I just used laundry soap and water to get rid of mine. It took two applications, a week apart.

 

[Deep Sea Diver]

Newbie here. Do you have a particular copper treatment you recommend? I've been practicing on a bunch of junipers (Japanese, procumbens, etc), and would like to keep them alive past winter.

The primary fungicides used here are:

3% H2O2 diluted in H2O at ratios of 3 TBSP / QT for fall winter foliage and

any basic Copper fungicide. Bonide is as good as anything

2-3 x during winter storage for juniper.

All the Junipers are medium bark mulched on, around and under (for drainage) when placed in the ground out of full sun and shielded from the prevailing winds.

Cheers
DSD sends

 

[Paradox]

The primary fungicides used here are:

3% H2O2 diluted in H2O at ratios of 3 TBSP / QT for fall winter foliage and

any basic Copper fungicide. Bonide is as good as anything

2-3 x during winter storage for juniper.

All the Junipers are medium bark mulched on, around and under (for drainage) when placed in the ground out of full sun and shielded from the prevailing winds.

Cheers
DSD sends

You spray the hydrogen peroxide on the foliage in the fall?