Caring for bonsai – tips and things worth knowing

Bonsai are plants that are kept small as miniature trees by horticultural measures. There are no special plant species. In principle, it is possible to carry out this historical garden art from the Far East with all woody plants. According to an old tradition, the plant and container should form a harmonious unit, which is why the bonsai pot is an essential part of bonsai culture. Bonsai art probably originated in China. In addition to conifers and deciduous trees, trees with decorative flowers are often used. There are outdoor and indoor bonsai, the latter should be indoors at temperatures below 15 °C.

Worth knowing outdoor bonsai location care watering fertilizing pruning repotting species pruning pests & diseases FAQ

Interesting facts about bonsai

Botanical name: bonsai
Other names: mini tree, dwarf tree, miniaturized tree, miniature tree
Use: houseplant, decoration for garden, balcony and terrace
Features:A bonsai is created through certain human design measures, because not every miniature tree is a bonsai. The branches are formed with wire, placed in the desired position and regularly trimmed. In addition to the aesthetic design measures, care measures such as watering or fertilizing are a matter of course. The fascinatingly designed plants require not only patience, but also manual skills and knowledge of the different styles. Bonsai plants have a clearly defined symbolic character in Asia. This is intended to represent harmony, balance, age and simplicity through the horticultural techniques used. The word «Bon-Sai» comes from the Japanese and means something like «plant in a bowl».

Tips for caring for outdoor bonsai

In addition to the bonsai species that hibernate indoors in winter, there is the group of so-called outdoor bonsai. These robust tree species are not kept indoors, but are only conditionally hardy. Due to the small root volume in trays, the root ball can freeze completely. This should be avoided, so winter protection is necessary against long-lasting permafrost. Originally, these plants come from areas in which there is a dormant phase in winter and mostly leaf fall. The most common types of outdoor bonsai are maple, larch, beech, elm and juniper. They are all adapted to the local climatic conditions. The frost hardiness of outdoor bonsai varies depending on the species and age of the plant. We recommend protecting the bowl with fleece or jute. Sinking the plant into the ground is also a way to protect the bowl and miniature plant from frost. It is important that the valuable plants are protected from drying out and that small amounts of water are regularly given, even in winter. Setting up in frost-free rooms at temperatures of 3 to 5 °C is another way of protecting the valuable creatures from low temperatures. Outdoor bonsai care and repotting largely follow the recommendations for indoor bonsai. to protect the precious creatures from low temperatures. Outdoor bonsai care and repotting largely follow the recommendations for indoor bonsai. to protect the precious creatures from low temperatures. Outdoor bonsai care and repotting largely follow the recommendations for indoor bonsai.

In which location does the bonsai feel most comfortable?

Indoor bonsai are mostly plants that come from the tropics. Depending on their origin, the green plants prefer a bright location by the window without draughts, intense sunlight and high humidity. Too low humidity often leads to susceptibility to pests. It is advisable not to place the treasures above the heating. A good way to increase the humidity is to place the bonsai pot in a saucer filled with water and expanded slate. This significantly increases the humidity and improves vitality.

An outdoor location is beneficial for all indoor bonsai in summer. It is important here that from the end of May a gradual acclimatization to the outdoor conditions takes place. This avoids unsightly leaf burns. They should be put indoors in mid to late September, because indoor bonsai do not tolerate temperatures below 15 °C.

Our gardening tip: The miniature trees can be optimally placed on flower steps or bonsai shelves. Here the fascinating structures are space-saving and attractive and form a small landscape.

How do I properly care for my bonsai?


Wiring bonsai is the most important design technique of all. The miniature trees cannot be formed without the use of wire. Young branches usually grow upright and not horizontally or downwards as in older plants. The goal of wiring is to shape a bonsai into the desired shape, as is done with older plants. Branches are wrapped with wire and placed in the desired position. In addition to special bonsai wire, aluminum, copper or iron wire is suitable. Check regularly that the bonsai wire is not growing in. Disconnect the wire once the desired growth habit is in place.

How do I water my bonsai correctly?

All indoor bonsai need an even water supply and never standing water. How often you have to water depends largely on the location, the tree species, the volume of the bonsai pot, the room temperature and the season. Basically, a bonsai must be watered again as soon as the soil has dried. With the so-called finger test you can feel whether the soil is still moist or whether watering is necessary. Make sure that the bonsai pot has a drainage hole.

Our gardening tip: To water the bonsai, place it in a bucket, a bowl or in the sink. It is watered with low-lime water or rainwater. It is important that the bonsai substrate is wetted several times. Only when excess irrigation water flows out of the holes in the bonsai pot is the miniature plant sufficiently watered. As a rule of thumb, a dive can take place once a week, with watering in between. It is important in both processes that the excess water is poured off.

How do I fertilize my bonsai?

The miniature plant is optimally supplied with bonsai fertilizer. This liquid special fertilizer contains the right composition of the required minerals and thus ensures compact growth and vitality. Fertilize weekly during the main growth phase from March to August, fertilize once a month during the rest phase.

How do I prune my bonsai?

crown cut

Basically, bonsai care includes the regular removal of all dry branches and dried leaves. However, the most important care measure for bonsai plants is regular crown trimming. In addition to the limited root space, pruning is the most effective way to keep the miniature tree compact and low. The frequency with which the bonsai is cut depends largely on the species, the growth and the desired size. If you cut less, the trunk will thicken faster. More frequent cuts improve branching. Analogous to pruning, a distinction is made in bonsai pruning between shape or maintenance pruning and design pruning.


With the topiary, the current shape of the bonsai is preserved and refined in detail. This trimming is performed as needed during the growth phase and essentially involves removing the tops. This type of topiary stimulates the inner shoots of the trees and creates a harmonious overall picture.

design cut

The desired bonsai shape is determined here. It is important to know in advance which style the bonsai should have.

Our gardening tip: Depending on the bonsai style, pruning measures are necessary. Basically, when pruning, you should only cut off the tips of the young shoots. Vertically growing branches are removed or wrapped with wire and bent. Bonsai scissors, concave pliers and wire are ideal for the care measure.

root cutting

The roots are cut with every repot. Up to a third of the existing roots are cut off with sharp bonsai scissors. The root cut is necessary because the space available is limited and new growth is only possible through the care measure. A root cut is ideal for deciduous trees before they sprout and for coniferous trees in the fall.

Our gardening tip: The root mass is reduced by the root cut and the plant should form new fibrous roots. For better root development, it is important that fertilization is suspended for 4-6 weeks after repotting and root pruning.

How do I repot my bonsai?

Bonsai repotting is an essential maintenance activity. Due to the small volume of soil in the bonsai pots, it is important that the valuable plants are regularly supplied with high-quality soil. Special bonsai soil is optimally tailored to the needs of bonsai. This contains a high proportion of humus, which improves storage capacity, as well as nutrients in the necessary composition and is structurally stable. Repotting in early spring every 2 to 3 years is ideal. Repot the mini trees as follows:

Our gardening tip: repot your bonsai as soon as the root mass is too big for the bonsai pot. Soil compaction or lack of oxygen in the root area also makes it necessary to replace the soil.

What types of bonsai are there?

Depending on the species, the miniature plants are placed indoors or outdoors. Room bonsai (indoor bonsai) are all species that need to be protected from frost.

Outdoor bonsai or garden bonsai (outdoor bonsai) are hardy and tolerate frost. However, it is advisable to protect the shell with winter protection. In between there is the group of cold house bonsais. These tolerate some frost and are best placed in a bright and frost-free location in winter.


Japanese bonsai artists in particular have developed so-called basic styles over generations. Individual bonsai can be strictly upright or cascading, taking on inclined forms. Years can pass before the single plant represents one of the styles. On the other hand, the group or forest plantings, which are also known as Yose-ue, are more effective. Here there is more than a single tree in a bowl. The arrangement of the many trunks, which are of different heights and thicknesses, is particularly attractive. A harmonious picture is created by a main tree and other plants, but always in odd numbers. What is special about the forest form (Yose-ue) is that the relatively young trees give the impression of an older forest. More original bonsai can be found in China.

What pests and diseases can the bonsai get?

Like other plants, bonsai can be attacked by diseases and pests. In the right location and with good care, there are fewer problems, but the following abnormalities can still occur:

leaf fall

After a lack of water, the leaves wither, dry up and fall off. Yellow leaves are often a result of waterlogging, a lack of nutrients or over-fertilization. It is usually sufficient that the cultivation conditions are improved, sometimes repotting in fresh bonsai soil is necessary.


Aphids often appear in the winter months. In phases with less light and less growth, the pests multiply. It is usually sufficient to spray the plants with water and treat them with plant strengtheners. These bio-active agents contain natural plant extracts that contribute to the vitalization of the plant.

FAQ — Frequently asked questions about bonsai

Which indoor bonsai is suitable for beginners?

Ficus microcarpa is a robust plant that tolerates pruning well. The not hardy plant is ideal as a beginner’s plant because it is affordable and convinces with an attractive habit. It is important to have an outdoor location from May and indoors from temperatures below 15 °C.

What is a prebonsai?

A prebonsai is a blank that is the starting material for a bonsai. The bonsai blank was transplanted regularly and pre-cultivated by carefully cutting the roots. Thus, the prebonsai is the preliminary stage to the bonsai.

What does pinching mean in bonsai?

Pinching means breaking out the herbaceous shoot tip. Bonsai are often pinched with tweezers or a fingernail. By removing the terminal bud, the crown of the miniature plant becomes much more branched and delicate. Pinching is therefore an essential maintenance measure in bonsai design.

What can be the reason for brown or yellow leaves on bonsai?

Too much water is usually the reason for yellow or brown leaves. Furthermore, a location that is too cold or drafts, sunburn or drought damage can lead to lightening of the leaves or browning.

Which bonsai flowers?

In the field of outdoor bonsai, there are Japanese azaleas, crabapples, wisteria, various flowering cherries, firethorn, cornus, ornamental quince or forsythia as common flowering species. There are also azalea species that delight as indoor bonsai with a rich abundance of flowers.

Which bonsai needs little light?

Basically, indoor bonsai are mostly representatives of tropical regions. Therefore, they are used to intense sunlight and high levels of light. All bonsai therefore need sufficient light to cope with the special growth conditions, such as small soil volume and restricted growth.

Can indoor bonsai be cared for like ordinary indoor plants?

Like all other plants, indoor bonsai need water, nutrients, and adequate light to thrive. Due to the reduced volume of soil, caring for bonsai is more complex and requires a little finesse. The plants in the small bowls only have a limited ability to store water and nutrients. Furthermore, the indoor bonsai comes from areas with high light intensity. Due to these factors, care is more intensive than with ordinary indoor plants.

How do I care for my bonsai in winter?

The care of the bonsai in winter depends on the bonsai species. Outdoor bonsai are protected with fleece in winter and left outdoors. Indoor bonsai should be bright and at room temperature. Due to lower light intensity, growth is reduced in winter.