How do they grow oranges from seedless oranges?
Beacause they grow exactly the same oranges but take the syonellied out from the seed to begin with!
Naval Oranges are indeed seedless. The naval end of a naval orange is a "conjoined" twin making the whole orange sterile as soon as the flower starts to fruit. Thus not making any seeds. Also the only way to grow a naval orange tree is by grafting a naval orange branch onto another citrus tree, or from growing a plant from a naval orange root stock.