An ideal fruit tree site should have certain characteristics. First, consider what the low temperatures are during the winter. The hardiest fruit trees are apples, pears, and tart cherries.
Fruit trees need exposure to direct sun in order to bear and ripen good crops.
Fruit trees should not be planted in low areas. Cold air will flow into low areas making them more subject to frost when the trees are in bloom. Trees grown on hill tops will be less likely to suffer frost injury. Good air circulation helps control diseases because the foliage dries off quickly in the morning when there is a lot of dew.
Tree fruits require a deep well drained soil that holds moisture. They will not grow well where a poor subsoil is near the surface. Moisture retention can be improved by incorporating organic matter.
The best time to plant fruit trees is early spring. Plant the trees as soon as they arrive from the nursery. If planting is delayed the tree can be heeled in. Heeling in is the practice of putting the trees in a shallow trench and covering the roots with soil or a substitute such as sawdust. Do not leave trees heeled in for a long period of time and do not allow the roots to dry out. Soak the roots in water for 12 to 24 hours before planting.
Prune off any broken root and shorten any very long roots. Do not prune the root system any more than is necessary. Under no circumstances should the root system be pruned to accommodate a smaller hole. Dig the hole large enough to accommodate the roots.
Set the tree no deeper than it was in the nursery. A difference in the color of the bark will help identify the former planting depth. It is especially important to avoid deep planting on heavy soil. Budded or grafted trees should not be planted deeply. The stem above the rootstock will root and the effect of the rootstock will be lost. There is usually a bend or swelling at the point where the rootstock and scion meet.
When the hole is more than 1/2 filled with soil, fill it with water to help settle the soil and get rid of air pockets.
Mulch around the newly planted tree to help conserve moisture, control weeds, and reduce the amount of lawn mower injury. Mulching does provide haven for mice. Putting the mulch in a basin will help when watering.
Apple are hardy in most of Michigan and there is a good number of varieties. The dwarfs and spur types are good choices for small lots. Best fruit production requires growing more than one variety for cross pollination. If there are many crab apples in the neighborhood they may provide enough pollen for fruit set. Jonathon and Golden Delicious are good pollen producers. Most varieties are not capable of pollinating themselves.
Trees consisting of more than one variety do not give good results. One variety generally crowds out the others.
The following varieties may be used in home plantings.
Lodi - Good for cooking, fair for fresh use. Yellow Transparent - Good fresh and excellent for cooking. Early to Midseason cultivars Jonagold - Good for cooking or fresh. Jonathon - Good fresh and for cooking. Paulared - Good for all uses, stores well.
Empire - Excellent fresh. Macoun - Good for fresh use. Midseason to Late cultivars Cortland - Excellent for both cooking and fresh. Delicious - Good for eating fresh. Idared - Excellent for eating fresh and cooking. McIntosh - Good for all uses.
Golden Delicious - Good for most uses. Mutsu - Good for all uses. Northern Spy - Good fresh or in pies. Red Delicious - Mainly eaten fresh or used as a dessert. Rome Beauty - Good baking apple, stores well.
Factors Affecting Fruit Set
Besides the source of pollen, other factors affect fruit set in apple. An apple tree only needs to set about 5 percent of the blooms to have a good crop. If a tree sets too heavily it is necessary to thin the fruits.
Trees that do not have the proper nutrition will not bear properly. The most important nutrient is nitrogen.
Temperatures below 40 degrees prevent pollen germination. The best pollen germination occurs at temperatures between 70 and 80 degrees. Low temperatures also inhibit bee activity thus reducing pollination. Frost will kill the blossoms. Fully opened apple blossoms are killed at temperatures between 25 and 28 degrees.
Strong wind or rain prevent bee activity. If these conditions occur when the trees are in full bloom the bees will not work. Intermittent rain will not seriously affect bee activity.
High humidity may prevent proper pollen release.
Most dwarf trees begin bearing in 3 to 5 years. Standard trees begin bearing in 5 to 7 year.
The tree will thin the fruit naturally. There are usually four periods of fruit drop but they are combined into two drop periods. The first drop is right after petal fall when flowers that didn't get pollinated fall. The second drop is called the June drop and is the most noticeable because apples have started to form. Pruning during the dormant season will reduce the fruit load. Small numbers of trees can be thinned by hand. The remaining apples should be 4 to 6 inches apart. Leave the largest apple in the cluster.
A standard apple tree should produce 8 to 12 inches of growth. Dwarf trees normally produce less growth. A standard tree producing less growth than it needs it should be fertilized. Do not over fertilize. Give young apple trees one pound of 12-12-12 fertilizer per tree per year of growth. Apply the fertilizer in a band under the drip line. Best results are obtained if the area under the tree is mulched. Keep the fertilizer at least one foot away from the trunk. The best time to fertilize is late fall or early spring. If done in late fall wait until after a killing frost. If a high carbon mulch is used, give the tree extra nitrogen.
While trees are young they should not be allowed to fruit. No fruit should be allowed to form for the first 3 years. The tree may be allowed to fruit normally from 4 years on.
The modified leader method begins by cutting back 1 year old, unbranched trees to 3 1/2 to 4 feet above the ground. If the new trees are well branched, skip this step in the first year.
The second year, save the most vigorous upright- growing shoots for a leader. Remove all sharp angled branches and select one or two branches to be scaffold branches (the branches that will make up the structure of the fruit tree). The saved branches should form a wide angle from the trunk, should be widely spaced from each other and located on opposite sides of the trunk. The lowest of the scaffold branches should be at least 2 feet off the ground.
At the next pruning, again save the highest shoot to be the leader. Save two more side branches for scaffold branches. The branches saved should be spaced far apart and should form wide angles from the trunk. The branches saved last year will need pruning. Each branch will have in turn produced branches, called laterals. On each scaffold branch, save two or three laterals that are at least 6 inches apart. Prune any laterals that are longer than the scaffold branch.
Never let the side branches get out of proportion with the top. If need be, cut or head back the side branches.
In the fourth year continue to save additional branches to be scaffolds as described before. Remove any rubbing branches and prevent the formation of narrow V crotches.
By the fifth year the tree will have all the scaffold branches required, and it will not be so important to maintain a well developed leader.
The instructions for mature trees are given below.
Pruning should be done during the dormant season, preferably in late winter. The benefits of pruning are increased fruit color, increased fruit size, vigorous fruiting wood, enhanced pest control, and controlled tree size.
Start at the top of the tree and work down. This allows cut branches to be pulled out of the tree as the pruning progresses downward. To control the size of the tree cut off upward growing branches at the point where a strong lateral branch joins the stem. This will lower the tree and make it easier to spray and harvest the fruit.
Start at the tip of a branch and work back. Leave the fruiting wood well spaced along the branch. Remove dead, diseased and broken branches as well as water-sprouts. Take out crossing or excessively long and spindly branches.
Undercut large branches to prevent the branch from peeling the bark when it falls. Some light pruning annually is preferred over heavy pruning intermittently.
Harvest late-maturing varieties when they are hard and mature for storage. Store only those that are in perfect condition.
Apples picked too green may acquire scald or bitter pit. Those picked beyond maturity will become overripe in storage.