Alaska Pioneer Fruit Growers Association

Why Fruit Trees Fail to Bear

September 16, 2000

reprinted  with permission from WSUCE  publication

Your fruit tree normally will begin to bear fruit soon after it has become old enough to blossom freely. Nevertheless, the health of your tree, its environment, fruiting habits, and the cultural practices you use can influence its ability to produce fruit. Adequate pollination is also essential to fruit yield.

 

If just one of these conditions is unfavorable, yields may be reduced. Perhaps the tree will not bear fruit at all. As a grower, you can exercise some control over most of the factors contributing to fruit production.

 

Bearing Age

When you purchase nursery-grown fruit trees, their tops will probably be from 1 to 2 years old. The length of time from planting to fruit bearing varies with the type of fruit. Trees that grow at a moderate rate generally bear fruit sooner than those that grow either too quickly or too slowly.

 

The ages (from planting) when trees can be expected to bear fruit are as follows:

 

Variety – Time in Years

 

Apple -2 to 5           Apricot – 2 to 5

Citrus – 3 to 5                 Fig – 2 to 3

Peach – 2 to 4               Pear – 4 to 6

Plum – 3 to 6           Quince – 5 to 6 Cherry, sour – 3 to 5

Cherry, sweet – 4 to 7

 

Dwarf apple and dwarf pear trees usually begin to bear 1 to 2 years earlier than standard-size trees.

 

Tree Health

Healthy trees produce good quality fruit. Weak or diseased trees produce fruit of poor quality or no fruit at all.

Pest problems involving insects and diseases, if not detected early and managed properly, can influence fruit production and weaken a fruit tree’s overall health.

When fruit trees are not sprayed properly or left untreated, diseases and insects may restrict the size and quality of the yield, although the tree itself usually continues to bear fruit. Pest management guides for commercial and home fruit trees are available through your local WSU Cooperative Extension office. Recommended product applications are important in preventing or controlling pest problems.

 

Climate and Weather

Most hardy fruit trees need a certain amount of cold winter weather to end their dormancy and to promote spring growth. When winters are too mild, spring growth is delayed, irregular, and slow. These factors extend the period of blooming, thereby increasing the possibility of frost injury.

On the other hand, extreme cold during winter dormancy may kill the fruit buds. Winter weather rarely threatens hardy apple, pear, plum, and sour cherry varieties. Sweet cherry trees, however, are relatively sensitive to cold until they become dormant. Peach trees are very vulnerable to cold weather. Their buds can be killed by midwinter temperatures around -10°F.

As the fruit buds grow and open, they become more susceptible to injury from frost. The exposed buds can usually withstand temperatures near 24°F. However, the open blossoms of practically all fruit trees may be killed if the temperature drops below 27°F.

When a heavy frost is expected, covering the trees will sometimes prevent bud or blossom injury, provided temperatures do not fall too low and the cold weather is of short duration. Protective coverings may be effective, such as floating row cover material or old bedsheets.

During spring frosts, some commercial growers heat their orchards, but this method is impractical for home gardeners. Overhead irrigation provides effective frost protection when temperatures drop to 32°F. Ice that forms on buds provides an insulating effect until temperatures rise above freezing. After a severe frost, injured blossoms may appear normal; however, if the pistils (center part of the blossoms) are killed, the tree will not bear fruit.

 

Pollination

Most fruit trees need to be pollinated. Pollination is affected by cold weather and reduced pollinating insect activity. Without sufficient pollination, trees may blossom abundantly but will not bear fruit.

Some species of fruit trees have “perfect” flowers. Both the anthers, which contain pollen, and the pistils, which develop into fruit, are located in the same blossom. Trees that bear fruit through self-pollination, or set fruit without pollination, are called “self-fruitful.”

However, many types of fruit trees that have perfect flowers cannot produce fruit from their own pollen. These require pollen from another variety and are called “self-unfruitful.”

Some species of fruit trees do not fit conveniently into either category. Persimmons and dates have male trees that produce pollen and female trees that produce fruit. To grow them successfully, it is necessary to plant at least one tree of each gender near each other.

Almost all citrus trees are “self-fruitful.” Other self-fruitful types include quinces, sour cherries, apricots (except Perfection and Riland), figs (except the Smyrna type grown in California), peaches (except the J.H. Hale and a few others), and European-type plums such as the Stanley, Green Gage, and Italian prune.

“Self-unfruitful” types include most apple, pear, sweet cherry, and Japanese and American plum trees. To pollinate adequately, plant two or more varieties near each other. The following planting practices are recommended:

 

Apple. Plant at least two varieties of apple trees near one another. Golden Delicious, a self-fruitful type, is one of the few exceptions to this rule. Poor pollen-producing types, such as Gravenstein, Jonagold, Stayman, and Winesap, need to be planted with at least two other varieties to insure adequate pollination.

Sweet Cherry. Bing, Lambert, and Napolean (Royal Ann) cherry trees do not pollinate one another. Plant a pollinating variety such as Black Tartarian or Republican, Stella, Van, or a sour cherry such as Montmorency nearby.

Pear. Many varieties of pears are completely or partially self-unfruitful. For adequate pollination, plant at least two varieties together. Note: Bartlett and Seckel pears will not pollinate each other, and Magness cannot be used as a pollinator.

Plum. Since most varieties of Japanese and American plums are self-unfruitful, plant two or more varieties together.

 

Biennial Bearing

Occasionally, certain fruit trees such as apples bear heavily one year and sparsely the next. This  is called “biennial bearing.” The spring-flowering buds of most hardy fruit trees have actually been formed during the previous summer. Therefore, an especially heavy crop one year may prevent adequate bud formation for the following year.

Biennial bearing is difficult to alter or correct. However, you can induce a return to normal yearly fruit production by early and heavy thinning during the year in which the trees are producing their large yield.

About 30 to 40 healthy leaves per single fruit are needed to produce good quality. Within 30 days after bloom, thin remaining fruit to leave a single fruit every 6 to 8 inches along the branches.

 

Cultural Practices

Fruit trees need full sunlight for best production. Avoid placing fruit trees where they will be shaded by buildings or by other trees. Leave adequate space for fruit tree root systems by planting away from shade or forest trees.

 

A good watering and fertility program is also essential to maintaining a tree’s vigor and fruiting capability at its best. Water fruit trees deeply but at infrequent intervals. Do not over fertilize, especially with nitrogen, since overapplications can cause abundant foliage growth at the expense of fruit production.

 

Reduce competition from weeds or grass by cultivation, mulching, or weed product application around the base of the tree. Do not spray the trunk wood.

 

Good pruning practices are important. Excessive upright growth will delay fruit bearing and reduce the quantity of fruit produced. Prune young apple trees to develop a strong framework with a central leader and horizontal branches. Use the open-center approach with a well-spaced branching pattern or similar method for most stone fruits (cherry, peach, nectarine, apricot, prune and plum).

 

College of Agriculture and Home Economics, Pullman, Washington. Revised from USDA Leaflet No. 172 by Kerry Retzel, WSU Urban Horticulturist, Chelan County.

 

Issued by Washington State University Cooperative Extension and the U.S. Department of Agriculture in furtherance of the Acts of May 8 and June 30, 1914. Cooperative Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, color, gender, national origin, religion, age, disability, and sexual orientation. Evidence of noncompliance may be reported through your local Cooperative Extension office. Revised August 1995. Subject code 234. A. EB0838