Some of the major trunks off my 20 year old fig tree died this winter despite wrapping in blankets and tarps. Some of the major branches cracked right down the length of the middle. Now all I have is new growth from the very bottom near the ground from these branches. There is one nice healthy branch growing straight up the middle directly upwards. Should I prune back these really old thick branches and make this new one the new tree? If I leave them will they take energy from this new growth? Thanks for any help.