Like most other fruit trees, apples rely on cross-pollination to produce large crops. While most popular varieties grown in the home garden or small orchard will pollinate each other, some combinations work better than others. There are also some varieties that cannot be relied on to pollinate each other, which could result in trees that don't bear fruit.
A number of popular varieties successfully cross-pollinate Red Delicious, a popular home garden and commercial variety of apple. These include Gala, Fuji, Golden Delicious, Granny Smith, Rome, McIntosh and Jonathan. Other varieties good for cross-pollination of Red Delicious are Braeburn, Empire, Honey Crisp, Lodi, Spartan, Akane, Tydeman's Early and Tydeman's Red. A Red Delicious apple tree cannot pollinate another Red Delicious tree.
Golden Delicious apple trees are known as self-pollinators, meaning they can produce fruit without cross-pollination, but will bear much larger crops when other varieties pollinate it. Popular varieties for cross-pollination with Golden Delicious are McIntosh, Empire, Honey Crisp, Jonathan, Red Delicious and Yellow Transparent. In addition, Akane, Cortland, Lodi, Spartan, Tydeman's Early and Tydeman's Red can be successfully used for cross-pollination.
Prized for baking and eating fresh, Gala apples successfully cross-pollinate with a number of other varieties, but not with other Gala trees. Common cross-pollinators are Honeycrisp, McIntosh, Red Delicious, Fuji, Empire, Yellow Transparent, Lodi and Jonathan. Although they are among some of the most popular varieties, Gala and Golden Delicious are not reliable for cross-pollinating each other.
Yellow Transparent apples, usually grown for making applesauce, baking or freezing, are cross-pollinated by nearly all other popular varieties. They are also self-pollinating, but, like Golden Delicious, the trees produce a better harvest if pollinated by other varieties. Yellow Transparent pollinate well with Red Delicious, Golden Delicious, Gala, Fuji, Empire, McIntosh, Lodi, Spartan, Honey Crisp and Braeburn. Varieties that do not cross-pollinate well with Yellow Transparent include Jonagold and Red Gravenstein.
Due to their small size, hardiness and ease of care, crabapples are often used to cross-pollinate standard apple trees. Crabapples usually have longer bloom times than other types of apple trees, making them useful for pollinating several types of standard apple trees that bloom at different times. Excellent varieties of crabapples for cross-pollination include Dolgo, Manchurian, Snowdrift, Whitney and Wickson.