How to Fertilize Bonsai? Detailed Explanation of Methods and Principles

  The types of fertilizer for bonsai plants are mainly organic fertilizer and inorganic fertilizer. Organic fertilizers mainly include: human feces and urine, barnyard manure, poultry manure, green manure, bone meal, plant ash, soybean cake, sesame paste residue, etc., as well as waste organic matter from daily life such as fishy water and rice-washing water. Inorganic fertilizers mainly refer to various artificially synthesized chemical fertilizers. Commonly used ones include urea, ammonium sulfate, potassium dihydrogen phosphate, superphosphate, ferrous sulfate, etc.

  Applying chemical fertilizers is cleaner and more hygienic than organic ones, and bonsai kept indoors should mainly be given chemical fertilizers as top dressing. The nutrient elements contained in chemical fertilizers are relatively specific, so when a plant urgently needs a certain nutrient element or shows signs of deficiency, applying the corresponding chemical fertilizer is more effective than applying organic fertilizer.

  1. The four "mores": apply more when the plant is yellow and thin, apply more before budding, apply more during the flower-bud stage, apply more after flowering.

  2. The four "lesses": apply less when the plant is fat and strong, apply less when sprouting, apply less when flowering, apply less during the rainy season.

  3. The four "nots": do not apply when the plant is growing leggy, do not apply when newly planted, do not apply in the height of summer, do not apply during dormancy.

  Plants have different nutrient requirements at different stages of growth and development. Generally, in late spring and summer, plants enter a period of vigorous growth and should be fertilized more; after the beginning of autumn, growth slows down and fertilizer should be reduced to avoid leggy growth; in winter, most plants enter dormancy and fertilization should be stopped. For flowering and fruiting bonsai, phosphorus fertilizer should be increased during the flower-bud differentiation stage and before and after flowering.

  1. Base fertilizer

  Base fertilizer is the fertilizer applied to the soil at the time of planting. Base fertilizer is applied when potting or when mixing soil in winter, and mainly includes cake fertilizer, hair, poultry scraps, etc.

  2. Top dressing

  Top dressing is fertilizer applied during the flowering plant's growing season. Top dressing is applied during the growth period of flowering plants, generally once about every half a month, and the amount should not be too much. Top dressing for potted flowers mostly uses diluted liquid fertilizer as the main method. Diluted liquid fertilizer should be prepared in advance in spring and can only be used after being fully decomposed by the high temperatures of summer. There are two kinds of diluted liquid fertilizer:

  1. Fertilizer water: put crushed bone pieces, soybean powder, rice-washing water, sesame paste residue, etc. into a large vat, add water, cover, and place in sunlight to decompose at high temperature. When applying, add clean water to dilute it, and it is suitable for all potted flowers.

  2. Alum fertilizer water: in the prepared fertilizer water, add 500 g of ferrous sulfate (black alum) per 50 kg of water, and add water to dilute it when applying. It is suitable for flowers that like acidic soil, and alum fertilizer water also helps promote a deep green, glossy leaf color.

  Fertilization principles:

  1. Fertilization must be timely

  Timely fertilization means fertilizing when the flowering plant needs fertilizer. When the plant's leaves are found to have become pale and its growth is thin and weak, fertilization is most appropriate.

  2. Fertilization must be appropriate

  Fertilization must be applied differently according to the different growth stages of the flowering plant. For example, during the seedling stage, more nitrogen fertilizer is needed, the fertilizer water should be more diluted, and the frequency should be higher, to promote rapid and robust seedling growth; after the plant matures, more phosphorus and potassium fertilizer is needed. Foliage plants should be given more nitrogen fertilizer to make the leaves tender green, while flowering and fruiting plants should be given more phosphorus and potassium fertilizer to make the plant bloom earlier and bear fruit earlier, and also to make the flowers and fruits more brightly colored.

  3. Fertilization must follow the seasons

  In spring and summer, flowering plants grow quickly and vigorously, so more fertilizer can be applied; after the beginning of autumn, flowering plants grow slowly, so less fertilizer should be applied; in winter, when they are dormant, fertilization should be stopped.

  4. Fertilization must be timed properly

  Fertilization of potted flowers should follow the principle of "eat small meals often" (that is, "apply thin fertilizer frequently"). Generally, from the beginning of spring to the Beginning of Autumn, apply diluted fertilizer water once every 7-10 days, and after the Beginning of Autumn, apply once every 15-20 days.

  5. Fertilization must take temperature into account

  Fertilization should be carried out on sunny days. Potted flowers should not be fertilized around midday in summer when temperatures are high, because the pot soil temperature is relatively high and applying top dressing can easily damage the roots; application in the evening gives the best results.

  6. Fertilization must be accompanied by loosening the soil

  Before applying diluted liquid fertilizer to potted flowers, first rake the surface layer of the pot soil loose, and wait until the pot soil is slightly dry before fertilizing. After fertilizing, immediately spray the leaf surface with water to prevent residual fertilizer liquid from contaminating the leaf surface, and be sure to water once on the day after fertilizing.