Despite their relatively compact size, columnar fruit can also produce a surprisingly high fruit yield. To ensure that the plants have the necessary nutrients, care must be taken during planting and further care to ensure that fertilization is precisely tailored to the plants' needs.
How should you properly fertilize columnar fruit?
To properly fertilize columnar fruit, use a long-term nitrogen-based fertilizer in spring and a fertilizer with a low nitrogen content but higher potassium and phosphate contents in late summer. This is how you promote growth, fruiting and winter hardiness of plants.
The misunderstanding about fertilizing columnar fruit
Some fruit-loving hobby gardeners tend to be excessively cautious when fertilizing columnar fruit. Apparently the opinion is circulating in some gardens that consistent fertilization of the delicate-looking young plants would lead to undesirable overgrowth in plant growth. This can only happen to a very limited extent in fruit trees that have been bred specifically for use as columnar fruit, as the growth habit is in most cases genetically defined. Columnar fruit was usually selected for a particularly high fruit yield. It is therefore important, especially when growing in planters, to always supply sufficient amounts of nutrients for the formation of the fruits. This is only partially possible with compost and animal manure, which is why rich, long-term fertilizers in liquid or solid form (granulated) are usually recommended for fertilizing columnar fruit.
Fertilize immediately when planting and repotting
If columnar fruit varieties such as columnar pears or columnar plums are planted outdoors, the planting hole should be dug at least twice as large as the rootstock of the tree. A good foundation can be laid for later growth by filling the planting hole with a mixture of garden soil, mature compost and stable manure. Potted plants can also tolerate a certain amount of organic fertilizer when they are planted. This can be renewed when the substrate is replaced if the trees are repotted into a larger planter about every two to three years. The following fertilizers (among others) are suitable for long-term fertilization of the substrate:
- ripe compost
- animal manure
- Primitive rock flour
- Horn shavings
The right time and the interaction of different fertilizers
Pillar fruit should be fertilized at least once a year, but fertilizing twice a year may also be appropriate. First of all, the plants should be given fertilizer in spring as soon as the first leaves emerge. With this fertilization, a long-term nitrogen-based fertilizer for fruit trees can be used. The nitrogen it contains stimulates leaf formation and the growth of the plant mass, which lays the foundation for a good yield. A second fertilization can then be carried out in late summer, although a fertilizer with a low nitrogen content should be used so that new shoots no longer form shortly before the onset of winter. The fertilizer for late summer fertilization of columnar fruit, on the other hand, should contain more potassium and phosphate. These substances promote the woodiness of young shoots and thus ensure the necessary winter hardiness of the plants.
Tip
It's not always just a bad location or the wrong fertilizer if the yields of columnar fruit fluctuate greatly. With columnar apples, it can happen that after a year with very high fruit set, there are hardly any flowers to be discovered on the tree the following year. This is because the plants bred for a high fruit yield “use” so much energy to ripen the fruits that there is hardly anything left for the production of flower buds for the following year. For this reason, for example, on particularly rich columnar apples, parts of the possible harvest should be removed in advance and only around 20 to 30 fruits (depending on size and variety) should be left on the tree to ripen.
