Proper fertilizing of bonsai is what enables lush branches and leaves

  Fertilizer is closely related to plant growth and development. This is especially true for potted plants: because they grow in pots for a long time, their root growth is limited by the potting soil, and the range over which they can take up nutrients is relatively small. A sufficient supply of fertilizer is necessary to ensure normal growth and development, so fertilizing is all the more important. However, it is not that the more fertilizer the better; too much will produce the opposite effect. Fertilizing potted flowers requires doing it at the right time and in the right amount. During the stage of rapid growth of flower seedlings, fertilizer should be applied promptly; otherwise the seedlings will grow thin and weak and will not become good plants. During the stage when flowers are forming buds and blooming, if a large amount of nitrogen fertilizer is applied, buds will drop, flowers will fall, and there may even be no bud formation at all. If unrotted “raw fertilizer” is applied or too much fertilizer is used, fertilizer damage will occur, commonly known as being “burned to death.”

  It is understood that there are many cases of home potted-plant enthusiasts losing flowers to death because of improper fertilizing or improper watering. When the following situations generally appear, attention should be paid and measures taken to save the plants.

  1. If flowers and trees grow thin and weak, the plants are poorly developed, and the leaf color becomes pale, or white spots appear, these are symptoms of fertilizer deficiency. Nitrogen fertilizer should be applied promptly, along with some manure and fertilizers containing phosphorus and potassium.

  2. If branches and leaves grow especially luxuriantly, with leggy shoots emerging over a short period, and flower buds are small and stop developing, leading to bud drop and flower drop. This is caused by applying too much nitrogen fertilizer. For example, if potted monthly roses are given too much nitrogen fertilizer in spring, the branches and leaves become luxuriant and leggy and do not open well. In citrus, it causes successive flower drop and fruit drop. The remedy is to stop applying nitrogen fertilizer and switch to phosphorus and potassium fertilizers.

  3. If not long after fertilizing flowers and trees, the plants suddenly wilt and the leaves hang down, this is caused by applying unrotted fertilizer or concentrated fertilizer. In serious cases, the flowers and trees will quickly wither and die. If this is discovered, some clear water should be poured in to dilute the fertilizer concentration. In more serious cases, the pot and soil should be changed promptly, the roots should be trimmed appropriately, and the aboveground branches and leaves should be heavily pruned. Place the pot in a shady spot and spray water frequently to aid recovery.

  If bonsai plants are to have lush branches and leaves and abundant flowers and fruit, fertilizing is very important. Ten things to avoid should be noted:

  1. Organic fertilizers such as soybean cake and fish scraps that contain nitrogen, phosphorus, and potassium should not be applied if they have not been fully rotted;

  2. Liquid fertilizer of high concentration should not be applied without being diluted;

  3. During the rainy season, especially the plum rain season, fertilizing is generally not advisable;

  4. Fertilizing is not advisable under high temperature and strong light;

  5. Fertilizing is not advisable on a clear morning;

  6. For newly planted tree-stump bonsai, fertilizing is not advisable before new roots have grown;

  7. For plants just potted or repotted, fertilizing is not advisable before new leaves have sprouted;

  8. Fertilizing is not advisable when the potting soil is too wet;

  9. Fertilizing is not advisable during the plant's dormant period;

  10. For flower-and-fruit bonsai, fertilizing is not advisable during the flowering period.