Curled needles on JBPine

My Japanese Black Pines are in their second season here in Merced, CA.
Last year I noticed deformation of the emerging needles on a few but not all of the buds on them. Again this season the same is occurring. It is not on on all new shoots probably 25% of them. What is causing this? Thanks

MY 11, note this condition has now manifested on my JWPine. Not all but several of the new needles .
What is the cause?

Sorry I do not have a definitive answer for you Vance. I have noticed this on both JBP and JRP from time to time in very small amounts. I think it might be a sign of stress that causes the sheaths to restrict the developing needles rather than release them.
I have not observed any insects or signs of fungal issues associated with the curled needles! I just cut off the affected needle group when noticed.
However I have only seen it occasionally rather than a good portion of the foliage.
From the pictures you have posted it does appear that some of the shorter needles have been chewed on the tips!
So on that basis I would check for any sign of webbing or insect activity!
Hope someone else can help more!

Sorry just had something to add! possibility of nutrient deficiency! Water quality affecting uptake and or PH of soil components.

Hi Vance, I live in Clovis here in California just down the road from you. I think Frank has some valid concerns about a nutrient deficiency. My question to you is have you been fertilizing your trees? The other thing is JBP here in the valley can take the sun. Most of my JBP, other than my shohin JBP, have a long sun exposure. Good draining substrate and don’t keep them to moist. As far as water quality goes here again our valley water is very hard, some areas have a lot of particulate matter. I filter all my water and have noticed a big difference in growth of my trees.

I’ve been curious about this too. I usually only see a little and I don’t often see very much of it when trees are growing well.

Insects, physical damage, and nutrient or hormone issues all sound like good guesses. Will be really interested to hear if someone can point to a resource that has identified the cause.

Thanks Jonas & guys! As far as the “chewed” photograph: that was me poking my finger into the candle to see what was going on with a curl.
As far as fertilizer I have for the past ten years adopted Valavanis’s heavy doses with excellent results…(plenty of water flush after).
Yes the water is exceedingly hard as it spots my deciduous trees and even shows signs of accumulation on the bark.
Fortunately this condition is not on all the needle bundles. But it is in approximately 5-10% I suppose I Will carefully scissor trim…
As far
As soil all were repotted last month to a (non-organic) (no organic material) fast draining rock/particulate/turface about 3-4mm grain size ( my standard mix for years).they get 6-8hrs full sun.
My one JBP a very large one shows NO signs of this condition yet my P. Strobus has a few (am a bit worried here because it was accepted into the National Show this Fall…)
Thanks for your most
Kind help. Vance Hanna

Hi Vance, I’ll take a stab at this. Did you say that you repotted in July? Isn’t that the time during candle growth? I’m just wondering if the repotting might have disturbed the candles mid elongation. Your thoughts?