Fall Season & Bonsai

[Bonsai_Trooper]

Hello fellow bonsai people.
I apologize if this has been answered in the past or if it’s novice question. My JBP and cork elms have had yellow leaves/ yellow tips on needles. Is this normal this time of year? Im watering less since it’s beginning to cool down. I’m in Southern California; specifically El Segundo. Any insight is greatly appreciated.

 

[rockm]

Yep pretty normal.

 

[Paradox]

Yup, see the same on my trees

 

[Shibui]

Yellow leaves can be seasonal or nutrient deficiency.
Assuming you have been fertilising these trees?
Chinese elms may be shutting down for the winter but in areas with warmer winters Chinese elm may not lose leaves until the following Spring.
Pines don't go completely dormant either. Reduced fertiliser right through Winter results in much stronger Spring growth for those of us who have warmer Winters.