Juniper Chinensis Scale



So after watching the beginner video on identifying scale in junipers I’m fairly certain this is what I’m dealing with on this tree, as it fits all the symptoms discussed. It seems to be pretty widespread so I’m guessing a pesticide will be my best bet? I reduced the roots and repotted out of the 5g nursery container into a grow box a few days ago so I’m not sure if a systemic treatment like imidacloprid would be handled well or if it is safer to wait a few weeks for the tree to recover first. The nursery recommended a product called “Sevin” does anyone have experience with this product or is it safer to go big with Bonide and just nuke everything? Not sure if it changes anyone’s advice but I live in zone 10 and it rarely get colder than mid-high 40’s through the winter.

As a side question, does anyone have a practice of treatments for new nursery stock? I have this juniper “quarantined” from my other trees while it recovers but was curious if anyone has a practice of treatment when buying new stock from random nurseries.

I can’t only help by sharing when I aquire something new, I automatically put it a “quarantine” space in my garden that is isolated. Keep it there for at least about 2 weeks, until I have been able to inspect and see how any new growth is doing. Basically just manually inspecting for fungus or insects. If I am certain of an insect I will usually start with the lowest lethal approach manual, neem oil and so on. Unless I know it needs a specific chemical treatment then I would go right to that.

Actually since I learned that the trees are signaling for which ever is there (insect or fungus) because of (salts or metals) in excess I make sure they are getting rain water (to control for both those variables) by not adding both into a system that’s already signaling excess in one for sure.

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Thanks for the info! I’ll have to keep learning about recognizing and identifying specifics

Hey friend - I am currently dealing with a juniper Sabina that had an awful scale infestation that went unaddressed for too long. A quick recap of what’s helped

  • debriding the scale manually using a soft tip nylon toothbrush (every part of the tree). Absolutely essential because scale are difficult to eradicate otherwise
  • transferred to the ground from pot because of significant health issues
  • lime sulphur dormant spray 3x here through the winter
  • sprayed twice last season with insecticide (forgot the active ingredient) to combat the scale

As you can see in these photos, things got really bad. It’s particularly difficult on junipers because they often hide in the crotches of foliage and in the scale of the foliage. This tree was also purchased second hand, simply didn’t look close enough to see this.




It appears to be on the road to recovery now, we’ll see what happens this season. Note that because of all the stressful events most of the new growth is now juvenile scale foliage. I’ll send a more recent picture if you’re interested.

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Wow that is phenomenal recovery from such an infestation! Luckily mine is not that bad yet but I want to avoid getting to that point as needle tips are starting to die. Good advice with the brush, I’ll have to pull out some tweezers as well and try manually removing and then spraying with an insecticide. Is there a reason why you did not treat with a systemic insecticide? I haven’t pruned the foliage at all so going through by hand is going to take forever but maybe that is what is necessary for the tree.

I am having some problems with scale aswel this season and would love to hear your opinions.

Last week i did the spring branch prune on my juniper and removed about 40% of the old foliage by removing those branches. Then i noticed on the lower interior foliage a scale infestation.

The tree would be up for a repot (percolation is declining) but i decided it could still wait another year. But that was before i noticed the scale infestation. So i kinda think the problem might stem from a decline in health due to loss of percolation.

What would you do now? Still do a repot even though it had 40% branches and foliage removed?

The tree is isolated for the moment and i will try and mechanically remove what i can of those buggers.

Any advice would be very much appreciated.

Happy easter and best regards

Steven

I controled the one problem I had with a systemic insecticide (neo-nicotinoids). If you can still buy those where you live it does help.

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I found a combination of 3-1 systemic spray and mechanical debridement with a soft nylon brush. Once a week I would scrub visible scale away then spray all the foliage. I’m getting juvenile growth in some spots as it recovers but I’m not having much more needle die-back.

Worth noting I think the mechanical removal and something less aggressive than the 3-1 systemic would have worked but I haven’t pruned the nursery foliage back at all so it’s a massive bush and going through each needle was impossible

Quick update on my juniper from above. Seems to be doing pretty well, pushing new growth across most of the tree. No signs of repeat infestation (no scale, no wilted tips). This was a hard winter in the Netherlands this year (rainiest year on record) which doesn’t mix well with sun loving junipers.

I also decided to experiment this year and elected to try some itoigawa grafts.