Miniature trees have a long tradition in Asia and are becoming increasingly popular in our homeland. However, growing in cramped containers requires a lot of care. Nutrient supply is an important aspect.
How should you fertilize a bonsai?
Bonsai trees should be fertilized every two to four weeks, using mineral and organic fertilizers. The nutrient composition varies depending on the season: nitrogen-rich fertilizer in spring (NPK 12:6:6), balanced ratio in summer (NPK 10:10:10), and potassium-rich fertilizer in autumn (NPK 3:10:10).
Time
Basically, you should fertilize your bonsai when repotting. There is then a four-week fertilizer break so that the roots grow well. Miniature evergreen trees that are supplied with nutrients all year round are popular indoors. If the plants take a break, there is no need to add fertilizers.
How often you should fertilize depends on the product you choose and the needs of the specific species. In general, the artistic trees require a supply of nutrients every two to four weeks. Strong-growing trees such as privet value weekly fertilization.
Important differences:
- Indoor bonsais are fertilized regularly from spring to summer and less frequently in winter
- Garden bonsais receive additional nutrients between spring and autumn
- If the plants are sick, fertilization is not necessary as protection against pests
Mineral fertilizers
Basically you can use any NPK fertilizer that offers the right ratio of nutrients. The levels of nitrogen, phosphorus and potassium required depend on the stage of vegetation of the bonsai. Such complete fertilizers are available in liquid or solid form.
Requirements during the year
In spring, the trees invest their energy in developing leaves. They are well supplied with a nitrogen-rich fertilizer (NPK 12:6:6). During the summer months you can either use a balanced ratio (NPK 10:10:10) or support flower formation with a high potassium content (NPK 6:6:12). In autumn the plants prepare for winter rest, so the nitrogen content should be low (NPK 3:10:10).
Organic fertilizers
Biodegradable fertilizers leave a smaller ecological footprint than mineral products. As a liquid solution, they quickly supply the trees with nutrients. The more difficult dosage can easily lead to over-fertilization. Solid products release their active ingredients slowly and over a longer period of time. Compost is not suitable as the material must be incorporated into the substrate surface.
Procedure
You can supply your artificial tree with solid small chunks that will dissolve evenly over the next few weeks through regular watering. These are placed in small plastic baskets, which are placed upside down on the substrate. Several points anchor the basket in the ground.
Liquid fertilizer is mixed with the irrigation water and administered at regular intervals. It is better to fertilize the trees in smaller doses to avoid over-fertilization. If the plant receives too many nutrients, there is a risk of leaves falling off and, in the worst case, the bonsai will die.
Tip
As basic fertilizer, add 20 grams of horn shavings to one square meter of soil when repotting. For small bonsai bowls, this corresponds to the amount of a teaspoon.
