Some trees, known as self-unfruitful trees, need pollen from another species in order to bear fruit. The blossoms of other trees, called self-fruitful trees, both produce pollen and develop into fruit. If you have space enough for just one tree, it needs to be self-fruitful in order to bear fruit. All sour cherries are self-fruitful. Some sweet cherry trees need pollen from another species.
Self-Fruitful Sour Cherries
Sour cherries are ordinarily self-fruitful, but several hybrid cultivars have been added to these trees that produce cherries useful for desserts and pies.
•Balaton, a dark burgundy cherry, was introduced to the U.S. from Hungary in the late 1980s. •Early Richmond, a variety that yields abundantly, is good for cooking and ripens early •English Morello, a small tree, produces dark red cherries that ripen in early July. This is a good cherry for making pies. •Hanson bush cherry, an ornamental shrub, yields dark cherries. •Nanking, a dark red cherry, is popular in China and Japan. •North Star, a small, ornamental cherry tree, is related to the English Moreno. The University of Minnesota introduced this hybrid in 1950. •Meteor, a small, showy tree, yields an abundance of sour cherries in mid-summer. •Montmorency, the most popular sour cherry in the U.S., is grown commercially in the Midwest and East. This considered the best cherry for making pies.
Self-Fruitful Sweet Cherries
Traditional sweet cherries are not self-pollinating. Self-fruitful sweet cherries are almost all hybrids of popular bing, lambert, Royal Ann, and other cherries that require pollens from other trees. These self-fruitful sweet cherries include: •Blackgold, a sweet, dark red cherry, a hybrid of stark gold and stella, was developed by Cornell University. •Lapin, a deep-red, sweet cherry, ripens in July. •Skeena, a red hybrid cherry developed in British Columbia, was introduced in 1997. •Stella, a nearly black cherry similar in appearance and taste to the popular lambert, ripens in July. •Sweetheart, a self-pollinating hybrid, is firm and sweet, •Sunburst, a sweet, dark dessert cherry, is a Canadian hybrid. •White gold, a hybrid yellow cherry with red blush, was developed at Cornell University.
While stella and lapin are both self-fruitful sweet cherries, their yield will be improved greatly if they are cross-pollinated. If you want a bing, lambert or Royal Ann or other sweet cherry that is self-unfruitful and you have room for two trees, you should plant it close to a cherry tree that will serve as a source for the necessary pollen. If you do that, you need to choose a tree that blossoms at the same time.