Stressed Juniper, what’s happening?

Hello everyone!

In the topic “Dark brown foliage on Itoigawa Juniper” I described how my juniper lost 70% of its foliage due to a fungus.

After a treatment in the end of may the fungus receded completely, the tree lost its foliage (=years of work) and new juvanile foliage came out.
3 Months at 82F-89F (28C-31C) without a problem.

Now the juvanile foliage is turning yellow and honestly don’t have a clue on what it is going on:

  1. is this color normal for juvanile foliage?
  2. is the tree discarding the interior needles even if the foliage is scarse (see picture) or the color looks like a problem (fungus) going on?
    The picture shows needles turning yellow while the mature tips look intact.
  3. do you suggest to cut the long shoots to allocate energy to the rest of the foliage, promoting more mature foliage or cutting the arrows away would harm such a delicate tree?

Thank you!
Cheers,
Leo

Am sorry to hear it! I was hoping the previous treatment put the tree back on track. This kind of discoloration isn’t normal on non-variegated cultivars which makes me suspect the original problem is still around.

The attenuated shoots and healthy mature foliage emerging from the discolored juvenile foliage looks like a tree trying to grow through a fungal problem. As before, I don’t recognize the pattern but I’d guess the issue is with the roots as some growth tips are healthy and others aren’t.

Assuming the original diagnoses were accurate (and complete), it’s likely time for a second course of fungicides. Ideally switching to products in different groups would improve the effectiveness and hedge against resistance. Based on the labels of the original fungicides, you can identify alternative treatments for the phomopsis and kabatina. And if that doesn’t do the trick, then there’s likely another pathogen at play.

Now is a good time to treat the tree as there is some warm weather left before fall. If there’s an additional pathogen here, it’s worth trying an additional broad spectrum product in a different group or sending a sample (foliage and roots) to a lab.

Before doing any of that, I’d circle back to the original diagnosis (and diagnoser) and see if there’s any info about what the symptoms look like on juvenile foliage.

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