Maintain bonsai: Light, irrigation, fertilization, soil, repotting, temperature
Maintaining a bonsai is much easier than is often assumed. Although there are specific things to consider in bonsai care for each tree species, there are a few basic rules that apply to all bonsai trees. If you follow these Bonsai care tips or basic rules the Bonsai care all at once is quite simple.
Bonsai Cultivation - Factor light
Bonsai, like any plant, derive their energy from light. To do this they carry out photosynthesis. Light is the most important bonsai care factor at all. Always place bonsai plants in a bright position.
Especially when keeping indoor bonsai in your home, light plays a crucial role. A normal glass pane reduces the light significantly. With the double and triple glazing commonly used today, the amount of light available is already greatly reduced. If only a north window is available then the bonsai will reach their limit in the dark season (i. e. days are shorter than nights). They then throw off leaves. Especially when the temperatures are high at the same time.
Bonsai care - Factor fertilizer
Bonsai need building material = molecules to build cells. These they take up together with the water over the roots. During the growing season, fertilize your bonsai trees regularly with what the bonsai tree needs.
If, for example, a young bonsai plant or a prebonsai is to grow stormy in the growing phase to form a thick trunk, the bonsai plant needs a lot of nitrogen. Amino acids are formed from nitrogen, proteins are formed from amino acids and proteins are basic building blocks of any cell. If you want growth - fertilize them nitrogen-rich and much.
When maintaining more mature bonsai or at the end of the growing season (September-October), fertilization is somewhat less nitrogenous. But also here - don't let your bonsai "starve". The fertilizer is an important bonsai care factor. Bonsai are not malnourished small plants.
Bonsai care - Factor watering
The nutrients absorbed by the root must be transported to the points of consumption. The bonsai plant uses water for this purpose. The nutrients are dissolved in the water. The water evaporates at the stomata of the leaves, the nutrients remain in the bonsai plant and are used to build cells. New water with nutrients is taken up by the root cells and the cycle starts anew.
It is therefore important to water the bonsai correctly. Here the healthy middle is correct with most bonsai trees. I.e. do not water too little but do not drown the bonsai plant. Moderately moist is optimal for most bonsai trees.
Bonsai care - Factor soil
Bonsai roots consist of cells and these, like all other plant cells, need oxygen. In order for enough oxygen to reach the root cells, the bonsai must be well drained. Avoid in any case too fine Bonsai soil. This is only suitable for covering as the uppermost layer of earth. Experienced bonsai friends often sift the fine ingredients, especially the dust, before potting their bonsai and often throw this fraction away.
Bonsai care - Factor temperature
All processes in a living plant are temperature-dependent. This means that the higher the temperature, the faster the processes run. A temperature 10°C higher doubles the metabolism. The temperature is often hardly considered with the Bonsaipflege, plays however a crucial role e.g. during hibernation of indoor bonsai. If indoor bonsai in the winter half-year in the apartment get little light, they can hardly produce enough energy. They help their indoor bonsai a lot when they keep it as cool as possible so that the metabolism (which consumes energy) is not too high.
Bonsai care - New posts
Bonsai care: My bonsai tree loses leaves ?
A question to read frequently in every Bonsai Forum. Almost every bonsai lover has experienced leaf dropping at Bonsai. With a little background knowledge he loses his terror or can be avoided completely.
In the following we have collected some points that can help you to answer them.
Bonsai tree loses leaves: Reasons for leaf loss
- Complete leaf shedding in autumn: normal for most deciduous trees in temperate climates. Almost all outdoor bonsai lose their leaves in autumn. But also coniferous bonsai can naturally lose all leaves or needles in autumn. Typical examples: Primeval sequoia Bonsai (Metasequoia), larch (Larix), golden larch (Pseudolaris).
- Partial leaf shedding in autumn: is quite normal for many needle bonsai (for example pine - pinus). Needles of the past years are dropped. Whether this "partial dropping" is normal depends on the tree species. Many species of conifers discard needles after 2-3 years (for example Weymouth pine - Pinus strobus, Scots pine - Pinus sylvestris, Spruce - Picea), but some only much later. For example Black pines bonsai (Pinus nigra) lose their needles after 3-8 years).
Bonsai care - fertilization: Which factors are importend ?
As with other plants, fertilizing a bonsai vigorously is important for growth and for flowering and fruit formation. Bonsai should not be malnourished. Fertilize 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, 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.
Bonsai care - overwintering
The hibernation of Bonsai does not differ essentially from the hibernation of other, in pots held woods. In our opinion, hibernating a bonsai is uncomplicated. However, a few basic points must be considered.
Is the bonsai hardy ?
Depending on the home climate of a tree species, bonsai are more or less winter-hardy or frost-resistant. Roughly speaking, the Bonsai tree species can be divided into 3 groups according to their winter hardiness:
- Not hardy: Tree species from tropical and subtropical areas are not hardy. In their homeland, the temperatures don't sink below 3-4°C (exception in the mountains). They are genetically unable to resist frost. It is not possible to adapt bonsai from such areas to temperatures below 3-4°C. This group includes many room bonsai such as Ficus Bonsai and Crassula Bonsai.
- Low frost hardness: Temperatures around freezing point are tolerated for a short time. Such bonsai tree species come from areas where light frosts rarely occur. We call such bonsai Kalthausbonsai. This means that they need protection from severe and prolonged frosts. Typical representatives of this group are Mediterranean tree species such as olives and pomegranates, but also tree species such as the Chinese elm.
- Absolutely hardy: These bonsai come from areas with strong frosts in winter. Such bonsai can tolerate winter temperatures of -10°C or lower.
Repotting bonsai - The right time ?
- Bonsai soil compactation: Many bonsai soils disintegrate over time and then have to be exchanged.
- If the root mass is too large for the bonsai pot. The roots are then reduced by repotting with root pruning.
- In case of lack of oxygen in the root area. Mostly when the bonsai soil is too fine.
- Pests have accumulated in the soil. Rarely a repotting reason. Sometimes it's a possibility.
- When the soil is salinated, eg. after over-fertilisation with a mineral fertilizer (nutrient salt).
Repotting bonsai - General Information
- The best time for repotting for most plants is early spring (late February to early April). Injuries to the roots can heal quickly.
- Younger and fast growing trees are repotted every 1-2 years. With adult Bonsai (forming is essentially completed) normally a 3-5 year rhythm is sufficient.