For normal growth and development, in addition to carbon(C), hydrogen(Н), and oxygen(O), which the plant obtains from air and water, the plant must absorb nutrients from the soil, including macro and micro elements. The macro elements are: nitrogen(N), phosphorus(P), potassium(K), calcium(Ca), and there is also a need for various microelements in very small doses: magnesium(Mg), iron(Fe), copper(Cu), zinc(Zn), molybdenum(Mo), boron(B), manganese(Mn), sodium(Na), and other elements. All of these elements are vital for the plant's existence. This is especially true for the macro elements. An excess or deficiency of each of these elements has a significant impact on the plant's development. For example:
Nitrogen is necessary for regulating plant growth, leaves, and fruiting. A deficiency in nitrogen becomes noticeable quickly, with growth slowing down. An excess causes the elongation of new shoots, which weakens winter hardiness. Adding nitrogen-rich fertilizer is not done in the second half of the growing season.
Phosphorus. It promotes plant development and root growth. It enhances the plant's resistance to drought and frost.
Potassium provides the plant's resistance to stress (extremely high or low temperatures, excess or lack of moisture). The optimal amount of potassium strengthens the ability of buds to survive winter, and the plant's resistance to fungal and bacterial diseases.
Calcium. It is essential for normal substance metabolism in the plant.
In the case of bonsai, due to the limited amount of soil in the container, nutrients are quickly depleted. Therefore, regular addition of fertilizer that contains all these elements is as essential as watering. Without additional feeding, the plant develops weakly, leaves and needles become colorless, and it becomes more susceptible to damage from diseases.
Bonsai can be fertilized with both organic and mineral fertilizers, but they should not be mixed and added together. There are fertilizers specially designed for bonsai that contain all the necessary elements. Such fertilizers can be either liquid or solid, in the form of granules. Liquid fertilizer is dissolved in water at a certain dose and the resulting solution is used to water the plant as usual. Bonsai absorbs liquid fertilizer quite quickly, so it should be added every 2 weeks for deciduous and fruit trees, and every 3 weeks for conifers. Granular fertilizers have a longer action period. This type of fertilizer is either mixed into the soil or placed on top of the soil in a special small container. With each watering, a certain amount dissolves in the water and gradually feeds the bonsai.
If you couldn't find such fertilizer, you can use a combined fertilizer, which is sold in gardening or flower shops. Usually, such fertilizers contain all the elements necessary for plants. For bonsai, it is preferable to use one that dissolves well in water. Using such fertilizer is more convenient. The composition in percentages and the amount of water it should be dissolved in are always listed on the packages. When adding fertilizer that does not dissolve in water, you need to be very careful and accurately determine the required dosage, as an excess amount can cause the plant to dry out. Normally, fertilizer addition starts in early spring and ends in the fall. Fertilizer should not be added to newly transplanted plants. Fertilizer can only be applied 4-5 weeks after the start of vegetation, when the bonsai has properly rooted.
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