For apples, flowering is the most critical time. It decides how the yield will turn out. We show what needs to be considered when flowering.

Apple trees form flower buds in early summer

Apple trees (Malus domestica) form the flower buds for the coming year in early summer. Due to the hibernation of the plants and their own frost protection mechanisms, they get through the cold season well. In spring, however, the protective mechanisms are deactivated, the young flower buds awakening as soon as they have experienced a certain period of cool temperatures and subsequently sprout in suitable, warm and sunny conditions. This stimulus to sprout as a result of cool temperatures is called vernalization. This mechanism is found not only in apples, but also in many other plants. As a rule, however, the blossoming of apples takes place at a time when frosty temperatures can still prevail. Then it becomes critical for the apple blossom: late frosts in spring can wipe out the entire apple harvest.

Protect apple blossom from late frost

The blossoms of apple trees are particularly sensitive when they are already wide open. Late frosts are therefore a major problem for the trees. However, there are a few things to consider when planting in order to protect the plants from threatening late frosts. A sheltered and less wind-prone location does a lot to protect against frost. You can also protect your apple tree from frost on cold nights during the apple blossom with an air-permeable fleece. Some old apple varieties are also less susceptible to frost, so it can be worthwhile to grow them.

In commercial cultivation, other methods are used to protect the flowers from frost, for example frost protection sprinkling. The trees are constantly sprayed with water, creating an ice shell around them. Due to the crystallization heat of the freezing water, the temperature inside does not drop far below zero and the flowers do not freeze to death. Fruit growers also install fire barrels in their orchards and "heat" their blossoming apple trees on cold nights to protect the sensitive blossom from failure.

Late frost can already sproutingtree become dangerous

Apple Blossom: Thin out too many blossoms and small fruits

Many apple trees produce more fruit than they can support. As a result, the fruits remain small. It is best to thin out your apple tree to encourage fruit formation. When June falls, the tree itself sheds the unfertilized blossoms. If there are still too many blossoms on the apple tree, remove them by hand. Remove apples that are too close together or damaged as soon as you spot them. Two to three apples per spur are an optimal number to create a perfect balance between quantity (harvest volume) and quality (size and taste of the apples).

In order to promote the formation of fruit, the apple tree must be fertilized

The apple tree is not blooming: Why is that?

If your apple tree doesn't flower in the first year, there's no reason to panic. Young trees only flower after a few years. With a self-grown seedling, it takes even longer than with a grafted specimen (read more about grafting apple trees here). Depending on the variety, it can take 5 to 10 years before the first harvest. Conversely, the tree can also be too old and already in "retirement", so that it no longer blooms or at best very sparsely.

The blossoms of apple trees are particularly sensitive when they are already wide open

If you can observe an annual dependency in the abundance of the apple blossom, you have become aware of the so-called " alternance". A good flowering and harvesting year will be followed by a year with significantly less flowering and less fruit set. For this reason, too, the blossom in apple orchards is deliberately thinned out in order to achieve as balanced a number of blossoms per tree as possible and thus an even harvest every year.

In general, you should remember that the apple tree does not bear fruit on one-year-old shoots. The pruning in winter therefore plays a major role. To be sure that you can bring in a harvest next year, you must be careful not to cut off all biennial or perennial shoots. A new shoot, no matter how lush, will not ensure an equally lush harvest, because the newly sprouted shoots will not bear fruit. It should be noted that some varieties, such as 'Red Star Reinette', prefer to form their buds further forward on the shoots. In this case, shortening the shoots too much prevents flowering and thus fruit formation.

Pruning back in winter plays a major role, but not all biennial or perennial shoots should be cut off

Besides the age of the tree, the alternation and a poor pruning, there may be other reasons why the apple blossom does not blossom:

  • Poor growth
  • Over-fertilization: Too much nitrogen stimulates the plants to vigorous vegetative growth of roots, shoots and leaves − fruit formation and flowering are neglected
  • Decrepitude
  • Pest infestation (you can find important diseases and pests on apple trees here)

Tip: If you use a primarily organic organic fertilizer such as our Plantura organic universal fertilizer, over-fertilization is virtually impossible, as the nutrients are only released to the apple tree slowly and gently become.

There can be many reasons for the missing apple blossom. In some cases, you can specifically help your apple tree to bloom lushly and successfully. But even the blossoming of the tree is no guarantee for a good harvest. Frost damage can always throw a spanner in the works.

You can find all information about apple trees − from cultivation to care and harvest − in this special article.

Category:

Fruit