As with other plants, fertilizing a bonsai vigorously is important for growth and for flowering and fruit formation. Bonsai trees should not be malnourished. Feed your bonsai sufficiently and with the right fertilizer.
The bonsai fertilizers found in specialist shops contain all important nutrients in the right proportions for most bonsai. They can be of organic (e.g. Biogold fertilizer, bone meal) or mineral origin and often differ only in the mixing ratios of the individual components, especially the main nutrients.
The main nutrients are nitrogen, phosphorus, potassium, calcium, sulphur and magnesium, the trace elements are iron, manganese, boron and others.
During the growing period, the supply of nitrogen is particularly important. This is needed for amino acids and proteins and is indispensable for the cell structure. Horn shavings and horn flour, best mixed into the soil when repotting a bonsai, guarantee a good, very compatible, even nitrogen supply of our bonsai.
These main nutrients are normally present in the soil and are constantly absorbed by the roots. The resulting loss in the soil must be regularly replaced by fertilization, otherwise deficiency symptoms will occur.
The aim of fertilisation is to ensure optimum care of the plants. Both nutrient deficiency and overfertilization should be avoided. Both have a negative effect on the health and growth of bonsai.
In order to fertilize a bonsai properly, its current needs must be taken into account. These can be very different. The following factors influence the need for nutrients and should be considered before bonsai fertilization: (+) means higher need, (-) lower need, (0) no fertilisation necessary
- Growth (fast-growing (+), slow-growing (-))
- Substance structure (+) or preservation (-)
- Growth periods (+) or rest periods (-)
- Diseases (-)
- Stress situations (-), e.G. during hot summer months, repotting
- Flower (0). Fertilization does not harm, but the trees would be more recent shoots and possibly loose their flowers.
- More plant material in a bonsai pot (+), e.G. forest planting
- Type of bonsai (+ or - depending on species needs)
- Amount of undergrowth (much = +)
- Type of soil (permeable substrates, e.g., sandy soils, rock plantations, Akadama (+))
If a fertilizer contains only one nutrient, it is called a single nutrient fertilizer; if it contains several nutrients, it is called a multi-nutrient fertilizer. For the layman, we strongly recommend the use of a multi-nutrient fertilizer. These are very easy to dose. Deficiencies are avoided.
When supplying nutrients, the plant's absorption capacity must also be taken into account. In most cases, this is significantly increased by entering into a symbiosis with fungi in the form of so-called mycorrhiza.