Before learning how to grow apples you must first know that of all fruit crops apples are especially subject to an alternate bearing habit. That is, a heavy crop is followed by a light crop the following year. When a crop is lost to frost or failure of pollination at bloom time, the next year the crop set may be so heavy that the apple fruit will not size and there is no energy reserve to form fruit flower buds for the following season.
This pattern can persist for years unless growers aggressively pursue thinning of excess fruit early enough to establish a desirable balance between leaves and fruit that will grow and size a full crop of apples with energy to spare to form next year’s fruit flower buds.
Growers used to remove excess fruit by hand. There were never enough hands to get the job done early enough to ensure a crop the following year, unless the grower practiced blossom removal, which was risky if a frost occurred after the thinning process. Hand removal is prohibitively expensive, except for home orchardists.
The essence of the apple crop can be brought to full fruition by cautious, proper irrigation or totally blown away by an inappropriate or belated attempt to garner larger-size fruits with over-irrigation.
Excessive irrigation does produce fruits with larger cells that fill with water, causing the apples to bruise easily and to taste like water. Irrigation is one of the three vital apple growing practices that determine tree vigor.
Fertilization and pruning are the other two growing practices. Tree vigor determines the number and placement of leaves and ultimately whether sunlight reaches those leaves directly supporting developing fruit. It takes only 40-45 leaves to sustain an apple to maturity and full quality. These leaves need to be closely adjacent to the fruit to do a quality job.
Leaves on rapidly growing peripheral shoots and on top shoots may not only rob lower leaves of sunlight but may also cannibalize food resources to further the growth of more leaves.
Irrigation sustains all leaves in performing vital tree functions and in resisting the effects of intense summer heat through the heat moderating effects of leaf water transpiration to the atmosphere.
An interrupted or reduced water supply first affects vegetative growth, slowing or stopping the formation of new leaves. Periodic interruption of water supply over the growing season eventually slows new foliage growth to a standstill without reducing crop quality or quantity significantly, but rather enhances it especially the quality, which translates into salability.
Nitrogen can be applied either to the soil or foliage in the fall so that the mineral is stored in woody tissue over the winter and is available to support rapid cell division as growth is resumed the following spring.
All nutrients can be applied to the soil, but may not become readily available to the tree as they may combine with other minerals in the soil and be blocked and locked from further movement into the root zone and easy access by the tree.
The following essential minerals: phosphorus, potassium, calcium, magnesium and zinc move very slowly at best into the soil profile. In some cases they are best applied as foliage sprays, where they are absorbed by the leaves and returned to woody tissue as the leaves mature and fall.
A deficiency of zinc, as is often witnessed in commercial planting by the presence of very small, narrow leaves or shoots in the trees. The leaves usually are blotched with yellow chlorotic markings. A zinc sulfate spray at the rate of 5 pounds per 100 gallons water applied after harvest while some green leaves still persist will usually raise zinc levels to adequacy for several years, as will pounding zinc coated nails.
You are probably aware that an apple tree can easily gobble up 30-40 feet of space and requires seven to 10 years or more to settle down to producing fruit and is much harder to prune, thin and pick than a smaller more compact tree.
Smaller trees and more compact trees can be achieved by using size-controlling rootstocks and or spur type tops where available or by using a training system that produces small compact trees.
Don’t be in too much of a rush to harvest apples. When apples are picked slightly immature, they have a strong tendency to develop bitter pit, many small, dark sunken depressions around the blossom end. They also will taste starchy. Starch represents the apple’s accumulated food reserve over the growing season. Eventually it is converted to sugar, aroma and flavor compounds that makes apples taste so good. This conversion can take place on the tree or after the apple is picked.
Don’t irrigate close to harvest period. Cells fill with water, making the apple very subject to bruising in harvest handling. Allowing the trees to dry down for several days before harvest, greatly reduces the propensity of the fruit to bruise. Also avoid harvest on cold mornings, when there is very little draw on the tree’s moisture supply, again allowing the fruit cells to fill with water.
Harvest bruises if not severe will usually heal and disappear within three days if the apple is subjected to refrigeration or cold storage, after picking.
When to harvest apples?
Harvest should commence when the fruit starts to taste good and the skin color turns to yellowish green or greenish yellow. On red apple varieties check for the change from green to yellowish skin color when the red pigment has not totally filled over the surface.
Don’t pick all the apples on a tree in one picking. Start harvest by removing the largest and more mature fruit from the top of the tree. This fruit is usually more mature, because it has better access to sunlight. This gives less mature fruit in the interior of the tree a chance to grow and mature to perfection.
Also fruit stores better on the tree rather than in some hot garage or inside of a warm building. On the other end of the spectrum don’t leave the last fruit on the tree on too long. It will become overmature. Being heavily loaded with sugar, it will absorb rain water readily and swell and crack severely when any rain occurs when the fruit has developed a full yellow skin color.
After the fruit is harvested, it should be kept in a cool place to preserve its keeping qualities and prevent it from becoming overripe. Each 10 degrees Fahrenheit rise in temperature doubles the ripening rate. If possible, refrigerate soon after picking at temperatures near 32 degrees Fahrenheit.
If you refrigerate apples in a second refrigerator at a temperature of about 45 degrees Fahrenheit the apple’s storage life can be prolonged by placing it in a sealed plastic bag. This allows carbon dioxide from the apple’s respiration to accumulate in the bag and slows the respiration process.
Apples so stored often last until the following season’s apples are ready for harvest, especially for good storing varieties. The plastic bags also aid in moisture retention, reducing shrivel experienced in most refrigerators without special humidity control.
Apples store very well in the form of apple sauce and cider in a freezer. Allow for some expansion by not filling the storage container to the top. Freezing is an excellent way to enjoy apple freshness year round and utilizes any surplus crop. Whole apples don’t freeze and reconstitute as well as sauce and cider.
Now that you have learned how to grow apples, you can go ahead and enjoy this year’s crop, a truly fine one.