My family is about to move up to northern USA where its much colder most of the year, and im looking to plant teak trees. ive done a lot of research, but the stump (pun intended) i keep hitting is that its a tropical tree with low frost resistance. i figure ill start my trees in my house until theyre barely big enough to push through the door, but how can i be sure they wont freeze and die? i cant find much information on how an older tree can withstand the cold. any help is very appreciated
You could try using bonsai techniques, but the most likely situation is going to be that a different tree is chosen. The tree gets massive, and it cannot withstand temperatures outside of subtropical or the higher end of the temperate regions. Unfortunately, where you intend to move is so far outside of the tree's range that you would need to keep it indoors for quite a good portion of the year.
I would, highly, advise seeking to plant a tree that can survive in the area. Make sure that it falls within the USDA zone of the town that you end up moving to.