Korean Black Pine in training.

[bonhe]

I did some works on this tree today.
Before complete pruning of spring shoots


After. The arrow pointing to the branch which was at the front of trunk


That branch was removed to make the trunk line going unimpeded. The wound.


skin grafting


There was a old unhealed scar on the trunk


It was made into fresh wound knob cutter.


skin grafting


grafting tape was used


be continued

 

[bonhe]

Finished


Thụ Thoại

 

[Adamski77]

Could the Korean varieties of these trees be hardy in zone 4 with protection?

I used to live in Korea for several years... before moving to China. First of all KBP are pretty much everywhere in the mountains though growing naturally... temperature in Korea can go in Jan-Feb to -20C (or below... I was skiing once at -24C) but zone 4, where you are, can go as low as -34C so there is a difference. They will clearly need winter protection. My KBP did very well outside over couple of winters with only protection from wind though winters were more in -15C to -20C range.