Cherry trees on DWARFING rootstocks. The sweet cherry varieties we grow have been developed from the European bird cherry (Prunus avium), while the sour cherries (which are still tangy as well as sweet) have been developed from Prunus cerasus, a wild cherry from Asia. Cherries definitely need protection from birds and many growing methods have been developed to accommodate this eg. espalier, spanish bush or fans so that they can be netted.