This is the most widely adapted fruit tree, with varieties suitable for almost every climate zone. The fruit ripens from July to early November, depending on climate and variety. Most require between 900 and 1,200 hours of winter chill. In mild-winter regions, choose varieties with a low chill requirement, such as 'Adina', 'Anna', or 'Dorsett Golden'.
With the exception of 'Golden Delicious', all varieties of apples require cross-pollination for good fruit set. Certain varieties (such as 'Gravenstein' and 'Stayman') do not produce fertile pollen and will fertilize neither their own flowers nor those of other apples.
Standard trees reach 40 feet tall and wide but can be kept to 20 feet with pruning. Most gardeners plant dwarf trees ― to 5 to 8 feet high and wide ― or somewhat larger semidwarf sorts.
Training and pruning
Central-leader training is ideal for smaller and medium-size trees. Train larger trees to a modified central leader to keep fruit within easy reach.
Mature trees need only moderate pruning; remove weak, dead, and poorly placed branches and twigs, especially those growing toward the tree's center.
Pests and diseases
The chief insect pests are apple maggot, codling moth, and plum curculio, all of which infest the fruit. Codling moth is a problem everywhere, while the other two are found mainly east of the Rockies. Traps help control all three.
Apple diseases, including apple scab and cedar-apple rust, are prevalent east of the Rockies. To avoid these, buy resistant varieties. If you do have an infestation, you can help avert future ones by raking up and discarding all fallen leaves and fruit.