Apple Tree Grow Guide
Fresh, home grown apples: There’s nothing like picking your own apple from your own apple tree in your own back yard. The apple is the most widely grown fruit tree in the United States. There are apple varieties for almost every part of the country, from the Florida subtropics, to the frigid Adirondacks; and from the Arizona desert, to the rainy Northwest.
Worldwide, there are more than 7000 different apple varieties. Perfect Plants offers eight of the most popular. Many apple varieties sold to back yard growers are grafted onto dwarfing rootstocks, which prevent the trees from growing to full tree size. Dwarfing rootstocks also reduce tree vigor and can interfere with winter chilling requirements. Apple trees from Perfect Plants are grafted onto standard rootstocks. Ours do not stay small, but we believe they will be more satisfactory for most home gardeners.
Most apple varieties require a second tree of a different variety for cross pollination. Read more about cross pollination in our Fruit Tree Pollination blog. In general, any two apple tree varieties that are blooming at the same time can serve as cross pollinators for each other. Very early bloomers and very late bloomers, whose flowering periods do not overlap, will not be able to pollinate each other. Some apple varieties are listed as self-pollinating, but even these will usually fruit better if an appropriate pollinizer is nearby.
A Note About Pollination and Chill Hours:
Pollination happens when a pollinator (usually an insect) transfers pollen from one flower (the pollinizer) to another flower. Only then will a fruit develop.
All apple varieties require a cool, or “chilling” period in winter before they will flower in spring. Chill hours are the number of hours in winter that the air temperature is below about 45°F, and above freezing. High chill varieties require 1000 or more hours of winter chilling. Low chill varieties need less than 700 chill hours, and medium chill varieties are those that need 700 to 1,000 chill hours. Low-chill and medium-chill varieties usually can be grown successfully in high-chill climates, but high-chill varieties will not set fruit in low-chill climates.
Select at least two different varieties (for cross pollination) whose winter chilling requirements will be met in your location.
Site Selection and Planting
All fruit trees do best in full sun and if your goal is to harvest apples, you will want to place your trees in the sunniest location possible. The best soil is a fertile, humus rich, sandy loam that is well drained, and has a slightly acidic pH of 6.0-6.5. Avoid low spots where drainage can be slow. Standard size apple trees should be spaced at least 15-20’ apart and dwarf varieties 8-10’ apart.
Dig the planting hole three times wider and a little deeper than it was in the nursery pot the sapling came in. Spread the roots out in the planting hole as best you can. Roots that are still too long should be shortened. The graft union should be 2-6” ABOVE the ground surface. Back fill the hole, pack the soil firmly, and water deeply. Cut the top of the little tree back by about a third. Use stakes to support the new tree. Do not fertilize.
Water frequently and deeply for the first year.
A tip for those gardeners with limited space: espalier your apple trees! This means to train and prune them against a flat surface such as a fence or wall of a house. The branches grow in horizontal layers or tiers and makes it very easy to prune and pick your apples! More info on this here.
Care of Apple Trees
Fertilize in spring and again in early summer with a complete formula, like the one Perfect Plants sells, that includes the minor elements. Follow label directions. Never fertilize in late summer or fall as this can encourage new growth that could be damaged by an early frost.
Pests that attack the fruits, such as coddling moths; pests that attack the foliage and stems, such as aphids and scale insects; and diseases such as scab and mildew, will need to be controlled with a regular spraying program.
Probably the most important spray each year is done in late winter before the new leaves have come out. Use a dormant oil spray to kill pests that feed on twigs and stems, including scale insects and mites.
When the flower buds develop pink tips in spring, spray an insecticide to control aphids and other sucking insects. At this time, you should also spray a fungicide to control various rots and scabs. You may need a secondinsecticide application in late spring to control coddling moths.
In summer, a couple weeks after the petals have fallen, and as needed thereafter until the apples are near harvest, spray fungicide and insecticide.
Always follow label instructions.
Fire blight sometimes appears on young, fast growing shoots, turning them black and making them look as though they had been burned. It is spread by insects and there is no treatment for it except to completely cut off the infected shoots and remove them. Make the cut several inches below the blackened part of the shoot, and do so as soon as you notice the infection. Left alone, fire blight can kill an apple tree. ‘Delicious’ and ‘Cortland’ are resistant, but not immune, to fire blight.
Apple trees are usually pruned to a vase shape with a central leader. During the first dormant season, choose 4-6 branches with wide crotches to serve as scaffolding, and remove all others. You can train the crotches of the scaffold branches with spreaders inserted between the branch and the trunk. The scaffold branches should radiate evenly around the trunk and be at least 6” apart vertically. The lowest should be around 18” above ground. If there aren’t enough appropriate scaffold branches, finish the job the following winter. During the second dormant season, cut off the top of the young apple tree 24-30” above the top scaffold branch. Remove the weakest side branches from the scaffold branches. During the third dormant season we will remove all side branches from the scaffold branches except for the strongest two or three. Do not prune off the short shoots that may develop on the trunk. They aren’t hurting anything and they are helping to provide food for the tree. Continue using spreaders to widen the crotches of the scaffold branches.
Mature apple trees should be pruned as needed to maintain the desirable size and shape, and to remove dead wood, crossed branches, suckers, and overly vigorous upright shoots (called water sprouts).
Fruit is produced on short branches called spurs, which grow on wood at least two years old. Young trees may take 3-5 years after planting to develop fruiting spurs, but then the spurs may be productive for many years, so don’t cut them off.
Fruit thinning is usually necessary. Left to their own devices, many apple trees will set so many fruit that the weight will break branches. Also, when an apple tree bears too many fruit, it tends to have too few the following year. Strive to have one apple every 6” along the branches.
Enjoy and Happy Planting!