Easy to grow and productive, apple trees can be very rewarding, no matter how large or small your garden is. Beautiful in bloom, heavy with luscious apples, picturesque when old, apple trees are wonderful additions to the landscape. There are more than 7,000 varieties of apple of varying sizes, appearances, and flavors. Apple cultivars can be dessert (eating fresh), culinary (cooking), dual-purpose or cider making. There is surely one for you!
- Most apple trees can only be grown in hardiness zones 3-8 and require between 500 and 1,000 hours of winter chill (hours of temperatures below 45ºF (7ºC) in the winter for their buds to open in the spring). However low-chill varieties requiring less than 400 hours of winter chill can bear apples in zones 9-10 such as Lady Pink, Fuji, Gala, Granny Smith, Gravenstein or Jonagold.
- Full sun lovers, apple trees are easily grown in deep, loamy, moderately fertile, medium moisture, well-drained soils. They prefer a sheltered, frost-free position.
- Apple trees should be planted when dormant from late fall until early spring.
Apple Tree Sizes
- Since edible apple cultivars do not grow well on their own roots, most varieties have been grafted onto rootstocks and are classified as dwarf (8-10 ft, 2-3 m), semi-dwarf (12-15 ft, 3-5 m) and standard (18-25 ft, 5-8 m). The fruit itself is full size and not dwarfed.
- Dwarf and semi-dwarf apple trees will fit into the garden without sacrificing too much garden space. They can add a charming presence, tucked into a shrub border, or planted as a specimen.
- The type of rootstock also determines how long it will take to bear apples. A standard apple tree will bear fruit in 6-10 years, a semi-dwarf tree in 4-6 years and a dwarf tree in 3-4 years.
- Some apple varieties are precocious, producing fruit a year or so earlier, and reaching full production a year or so earlier. Among them are Granny Smith, Jonagold, Honeycrisp, Red Delicious.
Blooming Season, Pollination, Harvest Season
- Apples do not fruit well on their own. Most require pollen from a different cultivar (apples are self-incompatible) that flowers at the same time. A few apple trees are self-fertile but they produce better in the presence of a pollinator. Apples are grouped into 7 pollination groups based on their bloom season: very early season, early season, early midseason, midseason, late midseason, late season and very late season. Choose two different cultivars in the same or adjacent pollination groups and plant them within 60 ft. (20 m) of each other. Certain apple cultivars do not produce fertile pollen (triploids) and cannot fertilize other apples such as Gravenstein, Jonagold or Mutsu.
- Most apples ripen between late summer and late fall, depending on climates and varieties (early, mid or late harvest season).
Training, Pruning Apple Trees
- Young apple trees are suitable for all training forms: classic bush tree with a clear trunk, espaliers against a wall or fence, cordons (trees grown as a single upright or oblique stem, or as multiple upright stems growing from a single leg at the base), pyramid (small, neat cone-shaped trees) or stepovers (horizontal cordons on a short leg). If size is an issue, consider a dwarf bush, pyramid, cordon or stepover. These all can be grown in a small space, or even in a pot.
- Apples should be pruned every year to get the best crop. They also need to be thinned to about 8 in. apart (20 cm) if you want to reap the best-quality fruit.
- Apple trees trained as free-standing bushes are best pruned every winter, when the tree is dormant, to ensure a good cycle of fruiting wood and create an open goblet shape with a framework of four to five main branches.
- Apple trees trained as cordons, espaliers and pyramids should be pruned in summer to allow sunlight to ripen the fruit and ensure good cropping the following year.
Apple Pests and Diseases
- Keep an eye out for aphids, woolly aphid, rosy apple aphid, fruit tree red spider mite, mussel scale, codling moth, caterpillars.
- Watch for apple scab, apple canker, powdery mildews, blossom wilt and honey fungus. The easiest way to control diseases such as powdery mildew, scab, and fire blight is to plant a resistant variety such as Cortland, Honeycrisp, McIntosh or Red Delicious.