i just bought 2 3gal ligustrum that i want to keep compact as they grow tall. i will be placing them on either side of a large window facing the street. i want to prune to expose the trunks and shape the top into a dome/rounded shape. with them being so small do i go ahead and do this and just keep pruning and shaping to keep their shapes as they grow?? any advice is appreciated.....i haven't planted them yet they are still in their pots.