It is not the real pepper that is used to grow the bonsai - as it is a more shrub-like climbing plant, it is not suitable as a bonsai - but the Chinese pepper tree. Alternatively, you can also train the Brazilian and Peruvian pepper trees as bonsai, although these two species need significantly more heat than their namesake from China.
How to care for a pepper tree bonsai?
A pepper tree bonsai is usually grown from Zanthoxylum piperitum (Chinese pepper tree). It needs a warm, partially shaded location, high humidity and regular watering. Fertilize with organic liquid fertilizer during the growing season. Cut and wire regularly and winter frost-free.
Botanical characteristics
The Chinese pepper tree, botanically Zanthoxylum piperitum, is also known as Sichuan pepper or aniseed pepper. The plant is native to southern China, which means it is also a tropical plant and is best kept in a greenhouse or winter garden. Despite the similarity in name, the pepper tree is not related to the real pepper (Piper nigrum), but instead belongs to the rue family and is therefore botanically much closer to the citrus family. Its fruits, flowers and leaves are used in both Japanese and Chinese cuisine. It is a shrub-like plant that, if left unpruned, can grow up to two meters high. Zanthoxylum piperitum also develops strong thorns.
Location
The Chinese pepper tree comes from the tropics and therefore needs a warm and partially shaded location. The plant usually does not like full sun. The plant should be kept indoors or in a greenhouse, but can also be grown outdoors over the summer. The temperature should not be less than 5 °C.
Fertilizing and watering
As a tropical plant, the Chinese pepper tree has a very high water requirement. To increase the humidity for a short time, spray the plant with a watering can. Both tap and rain water can be used for watering. The soil should always be moist, but not dripping wet. Fertilization is carried out during the growing season with an organic liquid fertilizer (€13.00 on Amazon). Fertilizing is only not necessary in winter or immediately after repotting.
Cutting and wiring
Of course, a bonsai tree does not stay small by nature, which is why it should be pruned regularly. For the Chinese pepper tree, such a shaping cut is carried out every four weeks between May and September. But not only shoots, branches and twigs have to be cut back, the roots too. Root pruning is done every two years when repotting. The tree is given the desired shape by wiring, whereby the branches and twigs are brought in the required direction with the help of wrapped aluminum wire.
Wintering
Since the Chinese pepper tree naturally cannot tolerate frost, it should definitely overwinter in the apartment or greenhouse. It is possible to overwinter under cold house conditions at around 12 °C or to remain in a heated living room. However, it is important to note that the warmer the tree is, the more light it needs. Warm overwintered pepper tree bonsais should therefore be irradiated with a plant lamp.
Tips & Tricks
You can also grow your Chinese pepper tree yourself from seeds and train it accordingly from the start. However, purchasing special bonsai seeds is not necessary.