Hi! I was recently given a Ginko Biloba, which I planted 2-3 months ago. It seems to be doing well. However, there is a fork quite low in the tree, and as a result it has two parallel trunks close together. About two feet above the fork, they cross and rub. I suspect it'll do the tree no favours in the long term. Should I cut off the smaller of the two trunks at the fork? If so, at what time of year should I best so this?