Why Fruit Trees Fail to Bear

A fruit tree will normally begin to bear fruit after it has become old enough to blossom freely. Nevertheless, the health of the tree and its environment, its fruiting habits and the cultural practices used 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. The grower can exercise some control over most of the factors contributing to fruit production.

Bearing Age

Nursery-grown fruit trees will probably be from one to two years old. The length of time from planting to fruit bearing varies with the type of fruit. Trees growing at a moderate rate generally bear fruit sooner than those grown either too quickly or too slowly.

Dwarf fruit trees usually begin to bear one to three years sooner than standard-size trees.

The age trees can be expected to bear fruit after planting

Variety Time in Years
Apple 2 to 5
Apricot 2 to 5
Cherry, sour 3 to 5
Cherry, sweet 5 to 7
Peach 3 to 4
Pear 4 to 6
Plum 4 to 6
Quince 5 to 6

Tree Health

Healthy trees produce good quality fruit. Weak or diseased trees produce little or no fruit or fruit of poor quality. The first step in fruit production is to keep the fruit trees healthy.

Two of the main problems involved are insects and diseases. A typical disease that attacks the leaves and fruit on apple and pear trees are scab fungi. The fungus, which causes brown rot (link to old site photo http://www.hort.uconn.edu/ipm/fruit/htms/brrotpic.htm) on apricot cherry, peach and plum trees can also attack the blossoms.

Diseases and insects can be controlled through the periodic applications of the proper insecticide and/or fungicide. These materials, if used properly, can be effective against most fruit tree pests. Contact the Cooperative Extension Center for control for specific fruits. When fruit trees are not sprayed properly or are left untreated, disease and insects may restrict the size and quality of the yield, although the tree itself usually continues to bear fruit. It is also possible to purchase varieties that are resistant to one or more of the common diseases.

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 and, thereby, increase the possibility of frost injury.

Extreme cold during winter dormancy may kill the fruit buds. Winter weather rarely threatens 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 10oF below zero. The stone fruits (cherry, peach, plum and nectarine) can lose cold hardiness due to extended midwinter warm periods. Damage to the flower buds can be extensive, especially if the warm period is followed by a very cold period.

As the fruit buds grow and open, they become more susceptible to frost injury. The exposed buds can usually withstand temperatures near 24°F. However, the open blossoms of practically all fruit trees will be killed if the temperature drops below 24°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. Polyethylene sheets or plastic bags that reach to the ground are usually effective, but cheesecloth and even old bed sheets may be used. If temperatures fall below freezing, buds and leaves that come in contact with plastic will be damaged or killed.

During spring frosts, some commercial growers heat their orchards, but this method is impractical for most home gardeners. An alternative method is to sprinkle the trees with water. Start when the temperature falls to the low 30s. Keep the water running until all the ice is melted. Water must be dripping off the ice at all times or the plant will suffer from frost damage. After a severe frost, injured blossoms may appear normal, but if the pistils (center part of the blossoms) are killed, the tree will not bear fruit.

Pollination

All fruit trees need to be pollinated. Without sufficient pollination, they 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. If they bear fruit as a result of pollination from their own anthers, these trees are called self-fruitful.

Self-fruitful tree fruits include quinces, sour cherries, apricots (except Perfection and Riland), peaches (except the J.H. Hale and several others) and European-type plums, such as the Stanley, Green Gage and Italian prune.

However, there are many types of fruit with perfect flowers that cannot produce fruit from their own pollen. These require pollen from another variety and are called self-unfruitful. Self-unfruitful types include most apple, pear, sweet cherry and Japanese and American plum trees. To pollinate adequately, two or more varieties of the same fruit type must be planted near each other. Apple will only pollinate apple, pear will only pollinate pear, and so on.

Some species of fruit trees do not fit conveniently into either category. Some have pollen-producing male trees and female trees, which produce fruit. To grow them successfully, it is necessary to plant at least one tree of each gender near each other. Fruits grown in Connecticut fitting this category are the hardy kiwi and persimmons. When selecting the varieties of the self-unfruitful tree fruits, make sure the flowering periods of the different varieties overlap. The following planting practices are recommended for the self-unfruitful plants.

Apple

Plant at least two varieties of apple trees near one another. Poor pollen-producing types, such as Mutsu, Baldwin, Gravenstein, Satymen, Winesap and Rhode Island Greening, need to be planted with at least two other varieties to ensure adequate pollination of all.

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.

Sweet Cherry

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

Biennial Bearing

Occasionally certain fruit trees, such as apples, bear heavily one year and sparsely the next.

This is called biennial bearing. The buds of most hardy fruit trees have been set 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, it is possible to 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 are needed to produce good quality fruit. Within 30 days after bloom, thin to leave only four to seven fruit per yard along the branches.

Cultural Practices

Fruit trees need full sunlight for best production. Inadequate sunlight delays the beginning of flowering and may reduce the amount and size of fruit. Avoid placing fruit trees where they will be shaded by buildings or by other trees.

Trees will grow more vigorously and bear better if they have adequate space to develop their root systems. Do not plant them where roots of trees or large shrubs will compete for water and plant nutrients. To reduce competition from weeds or grasses, cultivate, use mulch or carefully apply a properly registered herbicide.

Apply adequate amounts of fertilizer to produce strong growth. Avoid excess fertilizer, which will produce weak, leggy growth and delay the setting of flower buds. Soil test prior to planting and every 3-4 years after that. Apply fertilizer based on test results. Foliar samples may also be tested and when the results are examined along with the soil test results, a more accurate fertilizer program may be developed.

Prune young apple, cherry, pear, and plum trees to develop a strong framework with a central leader and horizontal branches. Excessive upright growth will delay fruit bearing and reduce the quantity of fruit produced. Prune young peach and nectarine trees to an open center or open vase system leaving 3-4 main branches.

More additional information about growing fruit, contact your local Cooperative Extension center.

Revised by: Edmond L. Marrotte, Consumer Horticulturist, Department of Plant Science

Updated by: Mary Concklin, UConn IPM. 2012

This information was developed for conditions in the Northeast. Use in other geographical areas may be inappropriate.

The information in this document is for educational purposes only.  The recommendations contained are based on the best available knowledge at the time of publication.  Any reference to commercial products, trade or brand names is for information only, and no endorsement or approval is intended. The Cooperative Extension System does not guarantee or warrant the standard of any product referenced or imply approval of the product to the exclusion of others which also may be available.  The University of Connecticut, Cooperative Extension System, College of Agriculture and Natural Resources is an equal opportunity program provider and employer.