When selecting fruit trees, understanding their pollination requirements is key to a successful harvest. A cherry tree is considered self-fertile, or self-pollinating, if its flowers can be fertilized by its own pollen. For the home gardener with limited space, a self-fertile tree eliminates the need to plant a second, genetically different tree nearby to ensure fruit set. This trait allows for reliable fruit production even with a solitary specimen.
The Difference Between Self-Fertile and Self-Sterile Cherries
The ability of a cherry tree to set fruit with its own pollen is controlled by gametophytic self-incompatibility. This genetic system uses specific genes, called S-alleles, to prevent fertilization if the pollen grain shares the same genetic markers as the flower’s female receiving tissue. Most traditional sweet cherry varieties are self-sterile. This means their pollen is genetically rejected by their own flowers, necessitating cross-pollination from a compatible partner.
A self-fertile cherry tree overcomes this barrier through a natural genetic mutation at the S-locus. The most common mutation involves the S4′ allele, which renders the pollen non-functional in the recognition process. This allows the pollen tube to grow down the style unimpeded, permitting the tree to fertilize its own flowers. Self-fertile cultivars can also serve as universal pollen donors for many self-sterile varieties, as their pollen is rarely rejected by other trees.
Self-Pollinating Sweet Cherry Varieties
Sweet cherries (Prunus avium) are naturally self-sterile, but extensive breeding programs have introduced many reliable self-pollinating cultivars. These are often the preferred choice for small-scale growers. The ‘Stella’ cherry was one of the first widely grown self-fertile sweet cherries and remains popular for its dark red fruit. Another highly regarded variety is ‘Lapins’, which produces large, firm fruit and is known for its resistance to rain-induced cracking.
‘Sweetheart’ is a late-ripening, self-fertile cultivar that extends the harvest season, offering medium-sized, bright red fruit that resists cracking well. For those seeking an earlier harvest, ‘Sunburst’ is a mid-season option that yields large, dark red fruit. ‘Skeena’ is another dependable, self-fertile choice, known for its firm, dark fruit and consistent production.
Newer self-fertile introductions diversify the options available to gardeners. ‘BlackGold’ is a very late-blooming variety that can help avoid damage from late spring frosts. ‘WhiteGold’ is a yellow-blushed sweet cherry, contrasting with the traditional dark red varieties. ‘Santina’ is a cultivar from the Canadian Summerland program, which blooms mid-season and produces firm, medium-sized fruit.
Other self-fertile types include ‘Sonata’ and ‘Symphony,’ which are known for their reliable yields and good fruit quality. The availability of these varieties means growers can select a tree based on factors like ripening time, fruit size, and disease resistance. This eliminates the complication of pairing it with a specific pollinator.
Pollination Status of Sour Cherries
In contrast to sweet cherries, sour cherries (Prunus cerasus), often called tart or pie cherries, are overwhelmingly self-fertile by nature. A single tree can be planted and relied upon to produce a full crop of fruit. This trait makes sour cherries a straightforward and dependable choice for both commercial growers and home gardeners.
The most widely planted sour cherry variety in North America, ‘Montmorency,’ is self-pollinating, known for its bright red color and ideal tartness for baking. Similarly, ‘Balaton,’ a Hungarian variety, yields a darker red and firmer fruit than ‘Montmorency’ and is also reliably self-fertile. Cross-pollination with another sour cherry variety can sometimes lead to slightly increased yields, but it is not required for fruit set.
Other common varieties, such as ‘North Star’ and ‘Meteor,’ are also self-fertile, ensuring consistent fruit production. The primary consideration for planting sour cherries is selecting a variety that is well-suited to the local climate and has the desired flavor and usage characteristics.