My plan for this pine is to allow the trunk to thicken and create a medium size tree design. I’m in zone 9, and it’s already getting to the 90’s during the day and high 60’s at night. Is it to late to repot into a large colander with bonsai mix? I plan to leave the tall branches untouched and let grow as sacrificial. When should I be cutting back the whorls to the strongest branches? Can I Repot and still decandle the lower branches this summer?
I’d let the tree grow for now without repotting.
The next step will to determine the trunk line and, if necessary, add bends to make the trunkline interesting. The earliest time to wire would be summer, otherwise the normal time to wire will be fall.
The only reason to decandle this year would be to stimulate needle buds where you need new branches. If you don’t need new branches this year, you can postpone decandling.