The most common method for breeding flowers is through heterosis, which is also called "outbreeding enhancement." This involves taking outstanding examples of a cultivar, and then cross-pollinating with another cultivar to create a hybrid that demonstrates traits that are superior to both of its parents.
花卉最普遍的育種方式是「雜種優勢選種」，也就是先以自交方式選出性狀優秀的植株，再與其他品系進行雜交，藉此產生比原來近親交配的「自交系」更優良的「雜種優勢」品種。