Juniper Browning! Unsure of what to do!

[DarkChoco]

Hello all!,

Thank you for taking the time to read this topic!

My mind is currently racing as to what to do now, and am worried I may overreact since I am new to the bonsai world. I’ve learned doing too much can be just as bad as doing too little.

I’m not sure what is happening to the trees below. Is this a fungal issue? Dried out due to lack of water? Other type of infestation? Chemical Burned? Need help! I’ve included photos and some info of what the tree has been through recently. First 3 photos relate to tree 1 and the last 2 photos related to tree 2.

Over the past week or so the 2 junipers my father had gifted me have started to turn brown almost overnight. They were green and fine last Tuesday, and about last Wednesday - Thursday started to get this color. The affected areas have stayed about the same, and hasn’t progressed from what I can tell, and if it has not enough that I noticed. (I might be looking at them too often to tell. I've started a daily photograph since yesterday to try and see if its gotten worse) Tree #2 started to brown in certain areas starting yesterday.

I live in Southern California and we have had a period of high heat over the past week (80 - 90 degree F weather). Both trees get full direct afternoon sun for about 4-5 hours during winter, more during the summer. Although I watered a little more than I normally would since the soil looked more on the drier side because of the recent heat. Before I water about every other day or so since the soil didnt look dry and felt moist about an inch or so down. I did wet the foliage on both trees during this time as well. (I realize that was been a mistake! )

In October 2020 I repotted them into new bonsai soil since the soil before was compacted, no root pruning was done.

About a month and a half ago I was using a homemade spray (Carl's spray I found on here) to treat what I believed to be a scale infection.

That’s all thats really happened since I received this in late August. If there is anymore information I can provide please let me know! Thank you all for any help you can provide!!

 

[Shibui]

Given the heat I would say dry is the likely cause or at least a contributing factor but there are some pests that can make juniper tips turn brown. Check for tiny scale insects on the leaves. Mites have also been known on junipers but we don't have them here so I can't give much direct advice.
Make sure the pots are properly wet. If they have been dry it is best to soak the pots in a tub to make sure water gets right into the roots then manage water better. I have some that got a bit dry last spring and lost a lot of leaves but are now doing OK. You may lose some sections of foliage but it will be replaced in time.

 

[DarkChoco]

Hi Shibui!

Thank you for you reply!

I believe that both did have scale, I was treating them for that a month before this happened. I will give that a shot the soaking a shot, it looks about time to water them this morning. Do you think misting / moving to a shady area for a few days is something I should do as well?

 

[Shibui]

I prefer not to move trees around too much. They adjust to the light level in one place then you move to a shady place and that throws the food processing in the leaves out until the leaves adjust. Then you'll move it back to sun and the leaves will burn or have to adjust again.
Better to pick a spot for the tree and keep it there. If you feel that the current place is too hot and too sunny find a new place by all means but shifting them back and forth seems to cause reduced growth and health.
Junipers are typically quite slow to show signs of stress. The cause of this browning is likely to have happened a few weeks ago. Most people have actually forgotten what conditions were like or that they forgot to water by the time the foliage turns brown. What did you teat scale with? Some oil base sprays can cause brown foliage in hot temps so that is another possible cause and would fit with the typical delayed juniper timeline.

Misting should not hurt - I believe junipers appreciate some humidity in summer - but misting won't return brown foliage to green.

 

[DarkChoco]

Understood! I will keep it on the stand that it is currently sitting on then.

I had treated the scale with a homemade spray I found on here. During that time, the weather was around 60-70 degrees no wind. I did rinse the leaves with a shower of water with the soil covered after about 12 hours. Followed to a T ingredients found below:

1. Water
2. Dish Detergent
3. Vegetable Oil (or Neem oil)
4. Rubbing Alcohol

I was also worried this could have been the result of juniper tip blight, but the onset was very fast. I don't have any hope of turning those areas green again. It should be no problem for me to prune the affected leaves off?

 

[Shibui]

We don't have juniper tip blight down here so I do not know what that looks like.
I agree that you can remove the worst affected parts. If it is from dry the tree could grow new shoots from many of those branches to try to fill the spaces so probably best to just lightly trim the brown and see what happens.
Removing bits of juniper seems like a bigger thing than it actually is. Initially the tree may look a bit bare but after a few months you will wonder where the spaces were. I feel that we often leave too much on trees which stops them growing. Opening up space seems to allow branches to develop better.
Good luck with the juniper. I hope the problem is just short term.

 

[Wires_Guy_wires]

Understood! I will keep it on the stand that it is currently sitting on then.

I had treated the scale with a homemade spray I found on here. During that time, the weather was around 60-70 degrees no wind. I did rinse the leaves with a shower of water with the soil covered after about 12 hours. Followed to a T ingredients found below:

1. Water
2. Dish Detergent
3. Vegetable Oil (or Neem oil)
4. Rubbing Alcohol

I was also worried this could have been the result of juniper tip blight, but the onset was very fast. I don't have any hope of turning those areas green again. It should be no problem for me to prune the affected leaves off?

Tip blight should start at the tips. I still see green tips in there and I don't notice the typical black spots that blight produces on every single scale of foliage.
Dish detergent and rubbing alcohol can be pretty damaging to the cuticle that protects your foliage from desiccation. When used in the wrong concentration, they do more harm than good.

Most scale doesn't respond to topical sprays, they require systemics that enter the sap stream and attack the scale from under their armor. Suffocating them with oil can work, but it's rather difficult because it requires multiple applications and it's not always effective. You'd need to hit every single one, or your problem will return within weeks.

I don't mix alcohol with oils. And when making a neem oil emulsion, I add the neem oil first to warm or hot water and then start adding small amounts detergent while shaking or stirring the mixture. At some point (usually after a couple drops, less than a teaspoon) the neem oil doesn't form a layer on top of the water anymore. This means the oil is now fully emulgated (micelle) and there isn't an excess of detergent. Alcohol inhibits the workings of detergents to some extent since it interacts with other hydrocarbons.
Ethanol is one of the least damaging alcohols to plants, but somewhere down the road people have been advising rubbing alcohol (isopropanol) to kill bugs. Yes, it does kill bugs better than ethanol, but it also damages the foliage a bit more than ethanol since isopropanol is better at dissolving waxes and fats.

I'd wait it out, see what happens. Those brown parts still have some life in them. Waiting a month or so before clipping the damaged parts could potentially help you save some parts that could start regrowing.