You likely already read this thread
And this one
If your still having problems and have that tree that never fruits and you don’t know why? Every year i have trees not produce due to exvessive wind. This year we have had a lack of pollinators. One hard case as an example is honeycrisp. I was told it was a difficult apple to get to bear apples. Noone knew why but they all have multicolored leaves and japanese beetle problems. Eventually I figured it out and the problem wasnt what I would have thought. My belief are its a photosynthesis and insect problem. Here is an interesting article about problems https://plantvillage.psu.edu/posts/3862-pear-pear-trees-that-don-t-produce-fruit
" Pear trees that don’t produce fruit
I was speaking to a friend of mine last week about our respective garden problems and she happened to mention that the pear trees she has in her garden do not produce fruit. Is this a pollination problem? What causes this?
Here is an article I wrote recently on this topic. Maybe your friend will find something to explain her fruitless pear trees.
If you have backyard fruit trees that you’ve nurtured along in anticipation of a delicious home-grown harvest, only to be disappointed by a lack of fruit, there are a number of possible causes. Maybe you have older trees that have been reliable bearers and they’ve suddenly decided not to produce fruit. What could be the problem?
With new, young fruit trees, it could just be their age. Most fruit tree nursery stock is sold when the trees are only one to two years old. Bearing age ranges from 2 to 7 years depending on the cultivar, rootstock and tree vigor. Dwarf trees will generally begin to bear sooner than standard size trees, with the semi-dwarfs falling in between. A tree that is growing at a moderate rate will bear earlier than one growing either too rapidly or too slowly. Growth rate is affected by environmental conditions, soil fertility, and moisture availability.
Plant fruit trees in a sunny location with enough space to avoid root competition with other nearby plants and trees. Competition from weeds or grasses can be reduced using cultivation, mulch or properly labeled herbicides. Avoid excess nitrogen fertilizer. This stimulates vegetative growth at the expense of flower bud production. Overfertilization is one of the most common causes of reduced flower bud production in the backyard orchard. This is due to the application of high-nitrogen fertilizer to lawn areas around the tree. Fertilizer recommendations for fruit trees are ¼ lb. of nitrogen per tree just after planting followed by reducing or eliminating added fertilizer until the tree begins to bear. Once trees begin to bear, if lawn fertilizer is applied that is adequate; if not, apply 0.1 lb. nitrogen per inch of tree trunk diameter. Broadcast the fertilizer over the root zone. To evaluate whether you should increase or decrease your fertilizer rate, note the length of new shoot growth during the previous season. The length of new growth should not exceed 18-20 inches. Of course, a lack of nitrogen and other nutrients that reduce tree vitality will also decrease flower bud formation, fruit development and fruit quality. A soil test can be used to obtain accurate fertilizer recommendations.
Excess pruning can delay the onset of flowering in young trees and stimulate vegetative growth at the expense of flower bud formation in bearing trees. In young non-bearing trees, prune only as needed for developing a strong, desired framework. In bearing trees, adjust the amount of annual pruning based on the length of terminal shoot growth as with fertilization rate. Prune out water sprouts.
If your fruit trees have an abundance of blossoms but fail to develop fruit, the most likely causes are related to the weather and pollination. Open blossoms can be injured by freezing temperatures. In some cases, the blossoms will still look normal but will not be able to form fruit because of injured parts. Small backyard trees can be protected if overnight freezing temperatures are expected. Cover the trees with plastic sheeting, old bed sheets, cheesecloth or similar materials. The cover should reach the ground to be most effective. Another alternative is to use sprinklers. Turn the spray on when the temperature reaches the low 30s. Ice will form on the tree surfaces, insulating the tissues from temperatures falling below freezing. This occurs because as water freezes, heat energy is released. The sprinkler MUST be kept on until the ice melts on its own or more severe injury can occur.
The other important considerations affecting fruit production relate to pollination. First, many tree fruits are self-unfruitful and need another cultivar as a source of pollen. This is true (with a few exceptions) of apple, pear, sweet cherry, Japanese plum and some European plums. Peach and apricot are self-fruitful and don’t require another pollinizer tree. When purchasing new fruit trees, it is important to understand each cultivars requirements. When selecting cultivars, consider the bloom period. For example, an early blooming apple will need a pollen producer that is either an early or midseason bloomer so that the bloom periods will overlap sufficiently. Some apple cultivars are poor pollen producers and need to be grown with two other cultivars to ensure a good pollen supply for all. These include Baldwin, Gravenstein, Stayment, Winesap, and Rhode Island Greening. One exception to the self-unfruitful apples is Golden Delicious, which is self-fruitful. If you’re just interested in growing one main variety of apple, plant one pollinizing tree for every 8-9 trees.
A few tree fruits require individual male and female trees; in other words female trees have only female flowers and bear fruit while male trees only have male flowers that produce pollen. In Connecticut, these include the hardy kiwi and persimmon. A good rule of thumb is to have one male tree for every six females.
Okay, now we have plenty of healthy blossoms and a good source of pollen; the next ingredient is the pollinator. The most important pollinators of fruit trees are bees. Minor pollinators include flies, wasps, beetles, butterflies, moths and other insects. Fruit trees that require cross pollination should be spaced in close proximity to each other without crowding to increase pollination. The better a flower is pollinated, the more seeds the fruit will have and it will be larger and more uniform. Cold, rainy or very windy weather during bloom will reduce bee activity which will result in reduced fruit set.
Some fruit trees, including apple, have a tendency to bear a large crop one year followed by little or no fruit the next year. The flower buds of the fruit trees are set during the summer before they open. If there is a lot of fruit developing on the tree, there are simply fewer nutrients available for flower bud formation. This tendency can be countered by practicing fruit thinning. For apple and pear, thin to one fruit for every three to four spurs or 4-7 fruits per yard of branch within 30 days after bloom. Thinning peaches and plums isn’t necessary to get a crop every year, but for larger fruit, thin to a spacing on the branch of 6-8 inches. Sweet and sour cherries, apricots and peaches will be able to produce flower buds while carrying a heavy crop.
Pest and disease management are important in maintaining the vigor of the tree and in the development of quality fruit. Some diseases affect the blossoms resulting in a reduction of yield while others affect the fruit as it develops. In general, diseases of the tree may reduce its vigor, decreasing its ability to put nutritional resources into flower bud formation and/or fruit development. Insect pests can decrease fruit production because they reduce plant vigor by feeding on the leaves and reducing photosynthesis or by feeding directly on the flowers or developing fruits.
Posted by: [Joan Allen]
Posted: March 26, 2013"
" Michele R. Warmund
Department of Horticulture
Most fruit crops require pollination to ensure that fruit sets. Pollination is the transfer of grains of pollen from the anthers (male floral part) to the stigma (female floral part) of a flower (Figure 1). Pollen grains get caught on the sticky surface of the stigma, germinate and produce a tube that grows down the style and unites with the female cell in the ovary. This union is called fertilization. After fertilization occurs, seeds develop and the fruit enlarges.
Honeybees are the most important natural carriers of pollen. As the bee flies from flowers on one tree to those on another in the orchard, pollen sticks to its body hairs. The bee rubs off the pollen onto the stigma and transfers additional pollen from the anthers as it visits the flowers. A honey bee may visit 5,000 flowers a day. Home plantings of fruit crops generally have enough wild bees for adequate pollination. However, in commercial orchards, beehives are generally placed in the orchard when the trees are in bloom to enhance pollination and fruit set. In some fruit crops, pollen is also transferred by the wind.
Each fruit crop, and even specific varieties within individual fruit crops, has distinct requirements for pollination. The following terms are used to describe the pollination characteristics of fruit crops.
Figure 1
Diagram of apple flower.
- Cross-pollination
The transfer of pollen between two different species or varieties - Self-pollination
The transfer of pollen within a single plant or among several plants of the same variety - Self-unfruitful or self-sterile
Plants in which very little fruit will set - Self-fruitful
Varieties that set fruit with their own pollen - Cross-unfruitful
Varieties that will not set fruit even when cross-pollinated - Intersterile
Neither of two varieties will fertilize the other - Pollinator
An agent (bees, insects, people) of pollen transfer - Pollinizer
The plant species or variety that produces the pollen
To ensure that fruit sets, the pollination requirement of the varieties of a given fruit crop should be evaluated before planting.
(opens in new window)Apple pollination
All varieties of apple trees should be cross-pollinated with another apple or crabapple variety. To attain the best fruit set on apple trees, the king blossom (the largest and first one to open) in the flower cluster must be pollinated. Thus, the bloom periods of the pollinizer and the king blossom of the apple tree must overlap.
In backyard plantings, two semidwarf apple varieties that bloom at the same time should be planted within 50 feet of each other. Two dwarf apple varieties with similar bloom periods should be spaced less than 20 feet apart to ensure the transfer of pollen between trees (Figure 2).
Figure 2
Apple and crabapple bloom periods. The shaded area represents the time of bloom.
Although some apple varieties, such as Lodi, Liberty, Empire, Winesap, Jonathan, Jonagold, Gala, Golden Delicious, Rome and Granny Smith may be listed as self-fruitful, they will set more fruit on an annual basis if they are cross-pollinated. Additionally, some apple varieties, such as Winesap, Stayman, Mutsu and Jonagold, produce sterile pollen and therefore cannot be used to pollinate other apple varieties. Many nursery catalogues include pollinization compatibility charts (Figure 3) or recommend good apple varieties to use as pollinizers.
Figure 3
Apple pollination. Except where indicated, varieties listed on the left can be used as reliable pollinizers for cross-pollination.
Manchurian crabapple, with profuse white flowers, is commonly used to pollinate early- to mid-blooming apple varieties, while Snowdrift crabapple is used for mid- to late-blooming apple varieties (Figure 2). When using a crabapple tree as a pollinizer, it should be planted within a similar distance to an apple tree as listed above.
In situations where a solitary apple tree is planted, branches of open fresh blossoms of another apple or crabapple pollinating variety can be placed in buckets of water and hung in the tree. Another way to ensure pollination where a single tree is planted, is to top-work or graft another apple variety onto the existing tree. To top-work an apple tree, 6- to 8-inch sections of branches of one apple variety are cleft-grafted onto terminal branches of another variety.
In commercial apple plantings, a row of pollinizer trees is often planted between every four rows of the main variety of trees (Figure 4). If pollinizers are placed within the row, every fifth semidwarf tree is a pollinizer and each pollinizer is offset in adjacent rows to stagger them throughout the orchard block. In high-density plantings of dwarf trees (5 to 6 feet between trees within the row), apple or crabapple pollinizers may be planted between eight to ten trees of another variety in the row.
Figure 4
Alternative planting plans to ensure cross-pollination of apple trees.
Beehives are generally placed in commercial apple orchards as the king flowers open. If hives are brought in before this time, bees may forage flowers of other broad-leaved plants instead of the apple blossoms. For this reason, dandelion flowers should be removed by mowing or by herbicide treatment before hives are placed in the orchard. In orchards where semidwarf trees are planted, one hive of a medium-strength colony (15,000 to 20,000 bees) is generally sufficient per acre. Two hives per acre are used in high- density orchards where dwarf apple trees are planted. Extra strong colonies of as many as 50,000 bees have been effective in pollinating four acres of semidwarf trees under ideal climatic conditions.
(opens in new window)Pear pollination
Most pear varieties are self-unfruitful. However, nearly all pears are suitable pollinizers for other varieties that bloom at the same time. One exception is Seckel, which is not a good pollinizer for Bartlett. Even though Anjou, Bartlett and Kieffer are partially self-fruitful, they should be cross-pollinated to produce heavy and regular crops. Pear flowers produce only a small amount of nectar, which is low in sugar. For this reason, more pollinizers and bees are needed for pears than for any other tree fruit.
(opens in new window)Apricot, peach, nectarine and sour cherry pollination
Nearly all common varieties of apricot, peach, nectarine and sour cherry are self-fruitful (do not require cross-pollination). However, the J.H. Hale peach is not self-fruitful but can be pollinated by almost any other peach variety with a synchronous bloom period except Elberta. Self-unfruitful varieties of apricots include Perfection, Riland and Rival. These self-unfruitful varieties can be pollinized by any other apricot variety.
(opens in new window)Sweet cherry pollination
Stella, Lapins and Starkrimson are self-fruitful. Most other varieties of sweet cherries require cross-pollination. Several varieties are intersterile and cannot fertilize each other. For example, Bing, Lambert and Royal Ann (Napoleon) will not pollinate each other. Refer to Figure 5 and nursery catalogues for pollinizer recommendations. In commercial plantings, beehives should be placed in the orchard on the first day of bloom
Figure 5
Cherry pollination. Except where indicated, varieties listed on the left can be used as reliable pollinizers for cross-pollination.
(opens in new window)Plum pollination
Most European plums (e.g., Bluefre, Blue Ribbon, Earliblue) either benefit from or require cross-pollination from another European variety. However, European or prune-type plums, such as Stanley and Damson, are self-fruitful.
Japanese plums, such as Santa Rosa, Burbank, Redheart, Shiro, Methley and Ozark Premier, require pollination from another Japanese or an American-Japanese hybrid. Follow nursery recommendations for suitable pollinizers.
(opens in new window)Pollination of small fruit crops
Grape, strawberry, raspberry, blackberry, gooseberry and currant plants are all self-fruitful. However, blueberry varieties require cross-pollination for fruit set. Thus, varieties that bloom at a similar time should be placed within rows or planted in adjacent rows.
(opens in new window)Pollination failures
Poor fruit set or low yields are often caused by poor pollination or frost during the period when trees are in bloom. Some of the common reasons for pollination problems can be the lack of a suitable variety for cross-pollination. Pollination failures also occur when bloom periods of two varieties used for cross-pollination do not overlap. Poor climatic conditions during bloom can also adversely affect pollination. Bees travel shorter distances during cool (below 50 degrees Fahrenheit), rainy or windy weather. In areas where native bees have been infected with tracheal or varroa mites, growers should rent beehives from commercial beekeepers that have strong colonies. Do not spray carbaryl (Sevin) or any other insecticide that could harm bees during the bloom period. To prevent bees from foraging flowers of dandelions or other weeds, mow the orchard or control the weeds with a herbicide before the fruit plants bloom. Wait to move the beehives into the orchard until the fruit crop has started to bloom and remove the hives as flowers stop blooming.
Beehive inserts can also enhance pollination in commercial orchards. Inserts are placed at the hive entrance and filled with pollen from a pollinizer variety. Pollen can be purchased from a commercial supplier and should be kept cool and out of the sun until it is placed in an insert. Use a teaspoon of undiluted pollen every several hours. A total of 1.4 ounces (40 grams) of pollen per acre is usually recommended."
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Apple and Pear Problems not caused by Diseases or Insects
Updated: April 8, 2021
Problems on apple leaves
Leaf spots/blotches on foliage - In a random or regular pattern are often caused by misapplication or spraying on hot days.
Leaf yellowing or browning
- Drought stress - first observed on newer growth. Leaf tips and margins may appear dry or scorched (brown and dry).
- Excessive water - older leaves uniformly yellow.
Leaf scorching /marginal burning (the edges of the leaves are dry and brown)
- Pesticide burn - including soaps and oils. Stressed plants are more likely to be burned. Emulsifiable concentrates are more likely to burn than wettable powders. Leaf margins are affected first. Leaves are particularly susceptible to burn when temperatures exceed 80-85°F. Copper, sulfur, and Captan® fungicides may cause leaf burn.
- Fertilizer burn/root damage - Marginal leaf scorch and root dieback caused by root contact with excessive salts from fertilizers.
- Drought stress is first seen on new growth.
Leaves curled, twisted, or rolled
- Sub-freezing temperatures after bud swell. First leaves will curl and be off-color.
- Herbicide injury - The new growth is affected first. Do not apply herbicides near fruit trees.
Wilting of foliage
- Drought stress - foliage wilts, droops and drops prematurely. May lead to twig and limb dieback. Provide adequate water during the summer and fall months.
- Root damage - associated with freezes, dry sites, drought, insufficient watering, or mechanical injury. Prune out affected branches. Don’t cultivate near the root zone.
- Poorly drained/heavy clay soils - limits root growth. Select suitable, well-drained planting sites.
Problems on limbs or trunk
- Frost/freeze cracks, sunscald - cracks usually occur on the south or west side of a tree. Caused, in part, by differential freezing and thawing of water in trees. Consider painting the trunks and large scaffold branches of young trees with white latex paint. Failure of trees to properly harden off makes them more vulnerable to frost crack and sunscald injury. Avoid late summer-early fall pruning or fertilizing.
- Trunk bark/wood is gouged or scarred - Lawnmower, string trimmer injury, embedded wires, or collars from tree support apparatus. - Mulch to within 6 inches of trunk. If tree support is necessary due to slope, high wind, or type of dwarfing rootstock, be sure to use a soft collar and adjust annually to allow for tree growth.
- Water sprouts/suckers - Environmental stress. Removal of large branches and limbs causes prolific growth of water sprouts directly below the pruning cut. In all cases promptly pull or cut all suckers and water sprouts at the point of attachment, unless you wish to select one to train as a scaffold branch.
- Dark, raised circles on the trunk with rough texture - Burr knots: caused by the progressive formation of aerial roots. Occurs frequently with dwarfing rootstocks M.7, M.9, M.26, MM.106, MM.111, and Mark. Burr knots can weaken a tree structurally if present in large numbers.
- Top of young tree breaks off at or near ground level - Failure of graft union or incompatibility between scion wood and rootstock. Check with suppliers before purchasing trees to determine the degree of compatibility.
Problems with apple blossoms or fruit
Blooms are brown and dry or water-soaked (blasted)/Bud cross-section reveals brown tissue
- Winter-kill of buds - extended periods of very cold temperatures. Young trees are more vulnerable. Blooms and buds at the ends of branches and facing upwards are more vulnerable. Avoid planting very early blooming cultivars. For further information on buds and killing temperatures.
- Spring frost damage to buds and flowers - open blooms are more cold-sensitive. Cover espaliered or short stature trees with tarps or quilts to prevent freeze damage.
- Low-temperature damage in early spring - trees may leaf out without flowering. Leaf buds are hardier than flower buds. Avoid planting very early blooming cultivars.
- Misuse of dormant oil sprays or pesticide sprays, including spraying when blooms are open or when temperatures are below 40°F. Over-spraying dormant oil, lime-sulfur, and other fungicides and insecticides may damage buds and blooms. Follow label directions.
Blossom drop
- Stressful conditions - drought, wind, low temperatures.
- Lack of pollinizer trees - almost all apple and pear cultivars are self-infertile. At least two different cultivars with similar bloom times are required for pollination and fertilization. Determine the pollination requirements of trees before planting. Pollination charts are available in fruit tree catalogs.
- Poor pollination/fertilization - bee activity is low during cool, wet weather.
- Spraying insecticides during bloom period - Avoid broad-spectrum pesticides that kill pollinating insects.
- Over-use of nitrogen fertilizers prior to bloom period. Reduce applications of high nitrogen fertilizers.
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"Diagnosis for No Pears on Tree
Healthy trees produce healthy fruit. If a pear tree is weak, stressed, or diseased, it will produce very little fruit or poor quality fruit. If a pear tree has no fruit, it may also be due to the fact that it did not receive the necessary amount of cold weather to break dormancy and encourage new growth.
All fruit trees require proper pollination in order to produce fruit. Most pear trees are completely or partially self-pollinated, so it is necessary to plant more than one variety if you wish to have fruit. Now that you know the most common reasons for non-bearing pear trees and when should pear trees bear fruit, you can better manage this issue. The most important factor in preventing a pear tree not producing is to provide the most optimal conditions for growth and overall health."
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10 Questions to Ask When Your Pear Tree Doesn’t Produce
Laidback Gardener
6 years ago
Pear trees are not supposed to be difficult to grow. After all, they’re fairly hardy, grow in most soils, and are even more disease-resistant than most other fruit trees. So it’s doubly shocking when you plant a pear tree, it survives and even seems to thrive, but fails to fruit or only bears very lightly. Why?
Here is a list of questions to ask yourself to try to pinpoint what went wrong.
- Does it have the basic conditions it needs to grow?
Pear trees are pretty easy to accommodate, adapting well to most soils, but they do require at least well-drained soil and plenty of sun. Especially avoid waterlogged soils.
- Is your pear mature enough to produce?
Normally a young pear begins producing in its 7th year. Some varieties are faster and start in their 5th year, but usually you can expect to have to wait 7 years. Patience is the name of the game when you’re growing pears!
- Is your pear tree adapted to your hardiness zone?
Almost any pear will bear fruit in zones 5-8 and the colder parts of zone 9 (winter chilling is needed for the tree to bloom), but you have to choose more carefully if you garden in zones 2 to 4. Typically a pear grown beyond its hardiness zone will still leaf out in spring, giving you the impression it’s doing fine, but doesn’t bloom because the flower buds overwintering on the tree were killed: they’re more vulnerable to cold than leaf buds.
Here is a list of pears adapted to cold climates you may find useful.
- Was the previous winter exceptionally cold?
Even if your pear tree is theoretically hardy enough for your local climate, if the previous winter was colder than normal, it is possible that its dormant flower buds froze, in which case there will be no harvest the following summer. The winter of 2014, for example, was exceptionally cold in much of North America and many pear trees of borderline hardiness didn’t bloom.
- Did it produce heavily the previous year?
Many pear trees tend to produce every second years, taking a year off in between. It is normal for these varieties to have an offyear.
- Was there a severe frost while it was in bloom?
Since pear trees usually flower later than other fruit trees, they often sail unharmed through the late frosts that do so much damage to other fruiting species. Still there are years when frost does occur while they are in bloom. If so, the flowers can be damaged by the cold and thus give no fruit.
- Did it rain persistently while it was blooming?
If so, the bees, who don’t like rain, may not have carried out their job of transferring pollen from one tree to another, yet bees are the main pollinators of tree fruits. This can result in a poor harvest or no harvest at all.
- Is there a compatible variety nearby?
Most pears are self-sterile: pollen from their own flowers will not fecundate them. So you need another pear with abundant pollen fairly nearby: no further than 200 feet (60 m) away. In addition, it must be of the same type: a European pear (Pyrus communis), also called common pear, won’t accept pollen from an Asian or Manchurian pear. You’ll need a different cultivar of the same species to ensure pollination. Therefore, another cultivar of European pear. Similarly, Asian pears (P. pyrifolia) need an Asian pear tree as a pollinator and Manchurian pear trees (Pyrus ussuriensis) require a Manchurian pear or a hybrid Manchurian pear (P. communis x P. ussuriensis) for pollination.
Although your nurseryman may have assured that your pear is self-fertile and doesn’t need cross-pollination, in fact, most of the so-called self-fertile pears still produce better harvests when there is a compatible variety nearby to ensure consistent cross-pollination. Those said to be partially self-fertile will not necessarily produce fruit when grown on their own unless conditions are perfect.
Learn more about the complexities of fruit tree pollination here.
- Is your pear tree surrounded by lawn?
Pear trees don’t need much fertilizer to be productive. In fact, when the soil is too rich, yields actually decrease. It’s especially important to avoid high nitrogen fertilizers (ones with a larger first number, like 30-10-10), because they stimulate the growth of longer and more numerous branches rather than bloom. Often pear trees surrounded by lawns grow very quickly, but flower little or not at all due to nitrogen-rich fertilizer treatments given to the nearby grass. Reduce your nitrogen fertilizer applications in about a 20 foot (6 m) radius and the tree should start to bloom.
- Did you prune your pear tree back harshly?
Pruning a pear tree is a much like pruning an apple tree, and is done at the same time of year: late winter or early spring, before the tree flowers. The general idea is to thin out the branches so as to allow better air circulation to the inner parts of the tree while removing any damaged, dead or misplaced stems. There are several Web sites that will give you an idea of how to proceed, but if you prune too severely and remove all the branches that were about to bloom, that would eliminate the harvest.
There you go! The pear trees really aren’t that difficult to grow, but do have certain needs you have to meet. Essentially, if you plant the right variety under the right conditions and supply a companion with compatible pollen, you’ll have pretty much covered all the major problems. All that’s left is to learn to be patient: patience is often a vital key to a green thumb!
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