I am not saying that someone in a hot climate can a pine alive for more than 4 years. However, as far as I know, I have never seen it.
Rob
Both myself and my good friend brought back large grafted JWP from Japan in 2000...both are alive and doing well 13 years later in South Carolina. On top of that I have had a 3 inch JWP from Suthin since 2005....no way a mame size white pine should live in this heat


One other thing to note...Many JWP for bonsai are field grown on Shikoku Island in Southern Japan...Same latitude as Charlotte, NC!! It was 80 degrees when I was there in late Nov. 2000.
The original grower of my tree, Hiro Yamaji (Sp?) was very impressed with the development of both the pines we purchased when he saw them here about 5 years ago in a workshop.
No secrets...except I avoid the hottest parts of the day during the summer...only sun up to midday. I leave the trees fully exposed on the benches in the winter.
All that said, I am not sure I have seen any one further south than me keep them successfully.
John