Apple tree does not bloom – the reasons and help

Young apple trees

In the case of a young apple tree, there are various reasons for a failure to bloom / fruit, which show up at different speeds:

1. Absence of a pollinating variety

Reasons: If the small apple tree starts to bloom but bears little or no fruit, it may be due to suboptimal pollination. This is not about the work of the pollinating insects (which will be discussed below), but for many apple varieties mainly about whether there is a suitable pollinator nearby. Since apple trees are usually foreign pollinators, they need pollen from another apple variety for fertilization.

Help: Plant suitable plant partners for the long term or refine them in the tree yourself. In the short term, a few flowering branches of a pollinating variety that are hung in the tree in buckets of water can help.

2. Bad growth

Reasons: If an apple tree grows poorly, it must first take care of the roots before it can flower. If the growth is not caused by damage to the young plant, the next most likely reason for the frugal apple tree is a (too densely) planted tree slice. Lawn on the tree slice can interfere with the formation of roots; other underplantings can also draw strong nutrients; Even moisture protection from bark mulch removes a little nitrogen.

Help: Keep the tree grate free as possible, fertilize if necessary.

3. Apple tree is too young to bloom

Reasons:Apple trees acquired in the nursery are grafted, among other things, so that the tree is able to develop flowers and fruits faster than when developing from its own roots. “Faster” does not necessarily mean “in the year after planting”, but the young trees need more or less time, depending on the variety, before they go into the productive phase. If the apple tree itself was grown from an apple core, an organic core from an old apple variety is usually selected. Then it takes longer anyway, wild apples bear at the earliest from the sixth year of standing, non-root apples of old varieties like to emulate them. In addition, a very robust tree usually grows here, but an apple tree of an unknown variety,

Help: Either wait or graft individual branches and refine them with a desired variety (you can find out how to do this in books or on the Internet).

Perhaps the young tree suffers from causes that can cause problems for older trees as well:

Medieval apple tree

The following reasons can be involved if an apple tree does not bloom at its prime or bears (satisfactorily):

1. Alternation

Reasons: Many apple varieties (e.g. ‘Boskoop’, ‘Cox Orange’, ‘Elstar’, ‘Ontario’, ‘Delbarestivale’) only wear really well every two years. This natural phenomenon is triggered by weather conditions and therefore mostly affects all appropriately predisposed apple trees in a region.

Help: These fluctuations in yield can be balanced out by means of care measures: If a narrow yield is justified in alternation, many new shoots usually grow in the summer in the year with little fruit, which prepare a plentiful harvest for the next year. If you remove these liberally, the next year’s harvest will not be so plentiful as to exacerbate the periodic fluctuation. In the year of the good harvest, the fruits in particular should be thinned out; Remove small, deformed, damaged fruits early and leave only one fruit hanging from a “fruit ball”.

2. Wrong cut

Reasons: Incorrect pruning does not promote the flowering system, but rather disrupts or prevents it if the tree is stimulated to grow so strongly that there is no longer any strength left for flowers and fruit. Too much pruning can also lead to strong shoot growth and thus reduce flower formation; some varieties prefer to flower on longer fruit branches.

Help: once again inform yourself well about the pruning care of the variety; if in doubt, it is better not to cut back a year than to make false suggestions.

3. Wrong variety

Reasons:The varieties for intensive commercial fruit cultivation are actually not intended for the home garden, but are grown inexpensively in bulk and therefore the mass trade (gardeners, garden centers, hardware stores, especially chains) are happy to offer them to end consumers. Who are then not always satisfied with the development of the apple tree. The variety ‘Braeburn’ is z. B. refined on very weak-growing substrates such as M9 and thus limited to the low vigor that is necessary in intensive cultivation. If there is not a tree every meter and the wood can develop freely, it unfortunately lacks the strength to do so on this base. The ‘Gravensteiner’ variety is the exact opposite pole: vigorous growth on any base and strong in the flower base; but as a triploid variety, biologically complicated in terms of fertilization, often affected by fruit fall,

Help: Sometimes early and strong winter pruning in December should give weak-growing varieties more zest for life, otherwise only carefully needs-based fertilization and waiting will help. In the case of excessively vigorous varieties, all growth-restricting measures and the improvement of the fertilization conditions up to planting another apple variety help. In addition, steep branches can be placed horizontally, the fertilization can stop; when the shoot has calmed down a bit with age, the yield is usually right.

4. Lack of pollination

Reasons: Honey bees are indispensable helpers in fertilization, but unfortunately their number has been falling for years. Wild bees and bumblebees can only partially replace the hard-working honeybees.

Help: The extreme solution is already practiced in China: flower fertilization by hand with a fine, soft brush. It is more far-sighted to encourage wild bees through natural hiding places and / or “bee hotels” and to attract all pollinating insects through near-natural planting with predominantly native flowering plants. In the short term, it also helps to “shake up” larger trees thoroughly on dry days in order to spread the pollen with the help of the wind.

5. June fruit fall

Reasons: At the end of May to the beginning of July pome trees (especially apple and pear trees) drop some of their fruit; 3 to 4 weeks after flowering and then again 6 to 8 weeks after. The natural process is brought about by nutrient competition; The main reason is lack of or insufficient fertilization. Cool, damp weather at the time of flowering, excessive fruit set, drought and codling moth infestation increase fruit fall.

Help: Improve pollination, water the apple tree in hot spells, fight codling moths, otherwise the June fall simply leads to the harvest of normal sized fruits and saves the arborist from having to thin out the overdeveloped fruit systems by hand (cleaning out before the June fall, especially in the shady areas of the tree, should however lead to even better fruit quality).

6. Late frost

Reasons: Well-known and obvious flower killer whose cold damage is not always immediately recognizable. The blossoms of the sensitive commercial fruit varieties freeze to death first (which is why the apple price in stores rose sharply in 2016 + 2017); these varieties are also sold to home gardeners in mass trade.

Help: A wide variety of measures are currently being tried out to prevent the flower organs from freezing to death; until the 2017 season without much lasting success, but it is worth staying tuned for information. In the long run, replacing an apple tree with a frost-hardy old variety helps, which the northerners can find here: www.elbtalaue.niedersachsen.de/download/26600/Obstsortenposter.pdf and the rest of the world with one of the many apple growers who have always or again (also ) cultivate old apple varieties.

7. Location at the compost

Reasons: The soil around the compost also gets a few nutrients during its ripening and every time you work on the compost, which can definitely lead to overfertilization at some point if only the apple tree grows near the compost.

Help: see overfertilization

8. Overfertilization

Reasons: A common cause in conventionally managed gardens because fast-acting mineral fertilizers with the main components nitrogen, phosphorus and potassium are applied there – which would have to be precisely calculated and dosed for each garden area after a soil analysis, which actually happens in the rarest of cases. Usually the fertilizer is applied by feeling; because the plants should have it good, if in doubt a little too much rather than too little. Too much nitrogen stimulates the plants to vigorous vegetative growth of roots, shoots and leaves; however, at the expense of generative growth with flowering and fruiting.

Help: Depending on the degree of over-fertilization, equip the tree slice with nitrogen-consuming underplanting or apply nutrient-depriving bark mulch, at first do not fertilize at all or give little potassium-based fertilizer. Then precisely dose the fertilizer for the not very hungry apple tree according to the soil analysis or (even better) switch to natural gardening, in which slow-acting organic fertilization counteracts the risk of over-fertilization.

Old apple trees

In old age, an apple tree also has to struggle with signs of age:

1. Old age

Reasons: Even in the apple tree, the metabolism breaks down with age and at some point no longer has the strength to form flowers and fruits.

Help: The best possible, needs-based nutrient and water supply can slow down the aging process somewhat.

2. Extensive pest infestation

Reasons: At some point old trees are so weakened that pests can easily infest them

Help: fight pests, pamper the tree with organic plant strengtheners and take good care of it.

3. Reaction to the weather

Reasons: Various natural processes such as the June fruit fall are more violent in the weakened old tree when damp, cold weather additionally worsens the supply situation.

Help: Clean out old trees before the fall of June, especially in cold and wet weather, and water them in good time if it is dry.

Apple tree that is lazy to carry

If an apple tree stubbornly refuses a sensible harvest despite devoted care, e.g. For example, because a less than optimal variety is in a less than optimal location or the genetics of a seed-raised apple dictate a “life on the sofa”, you can improve the carrying properties of the apple tree by controlling its metabolism.

You do this by influencing the flow of sap – giving a kind of aphrodisiac for apple trees; However, a rather brutal one: “Applying a fruit belt” and “Ringeln” are what the fruit growers call these incisions in the metabolism in order to direct the flow of sap to the desired areas in the tree. Both should only be done to trees where the damage can be tolerated in case of doubt, and even then only after thorough prior information.

Conclusion
There are usually reasonable reasons why an apple tree refuses to harvest or produces (far too) few flowers / fruits. Against a reasonable cause, there is usually also reasonable help, at most it may take a while for this help to work. Most apple trees can therefore be “persuaded” quite well to deliver a splendid bloom and harvest, please; and the skilled fruit grower even knows the means to emphatically remind of their duties in extreme cases (trees that cannot be moved, lazy to carry for no reason).