Pollination is the transfer of pollen required for fruit trees to produce a harvest, but it must occur between compatible partners for successful fertilization. The direct answer is no: an apple tree cannot pollinate a cherry tree. These two types of fruit trees are biologically unable to cross-pollinate because of specific, internal compatibility rules.
The Biological Incompatibility of Apple and Cherry Trees
Successful cross-pollination generally requires plants to be closely related, typically within the same species or genus. While both apple and cherry trees belong to the larger Rosaceae family (the rose family), their genetic distance is too great for them to interbreed. Apple trees belong to the genus Malus, classifying them as pome fruits. Cherries, plums, peaches, and apricots belong to the genus Prunus, classifying them as stone fruits.
The genetic material of Malus and Prunus is not compatible enough for the pollen to successfully fertilize the ovule of the other species. Even if a bee carries apple pollen to a cherry flower, the pollen grain cannot grow a tube down the cherry’s style to complete fertilization. The cellular and genetic mechanisms required for a viable seed to develop are species-specific. This difference in genera creates a hard barrier to fruit set, meaning planting these two trees next to each other will not result in a hybrid fruit.
Specific Pollination Needs for Apple Trees
Most cultivated apple varieties are self-sterile, meaning they cannot produce fruit by pollinating themselves or another tree of the same variety. To ensure a good harvest, apple trees require pollen from a different, compatible apple cultivar, known as a pollinizer. This compatible partner must have a similar or overlapping bloom time so the pollen is available when the receiving flower is receptive. The physical transfer of pollen between these compatible varieties is primarily carried out by insects, particularly honeybees.
Growers must also consider the ploidy of the apple varieties, which refers to the number of chromosome sets within the cells. Most apple cultivars are diploid, possessing two sets of chromosomes, and serve as good pollen donors for other diploid varieties. However, some popular varieties are triploid, having three sets of chromosomes. Triploid pollen is largely sterile and ineffective for pollinating other trees. A triploid tree, such as Jonagold or Gravenstein, requires two separate diploid pollinizers to ensure a crop on both the triploid tree and the surrounding diploid trees.
Specific Pollination Needs for Cherry Trees
Cherry trees are classified into two groups with distinct pollination requirements: sweet cherries and sour cherries. Most sweet cherry cultivars, including varieties like Bing and Rainier, are self-unfruitful. They require cross-pollination from a different, compatible sweet cherry variety to produce fruit. The pollinizer variety must have a matching or overlapping flowering period to be effective.
In contrast, most sour or tart cherry varieties, such as Montmorency and North Star, are self-fertile. A single tree can produce fruit using its own pollen. While they do not strictly require a second tree, yields are often higher if a different, compatible cherry cultivar is planted nearby. Regardless of the cherry type, the process relies on insect activity, as bees are responsible for moving the pollen necessary for fruit formation.