Fertilizing Methods and Precautions for Camellia Bonsai
Fertilizing camellias should be done selectively according to the different growth stages of the plant. During the growing period, camellias need topdressing, and quick-acting liquid fertilizers and chemical fertilizers are suitable. During the stage of sprouting branches and leaves, apply nitrogen fertilizer or a mixed fertilizer mainly based on nitrogen. Before flower bud differentiation, flower bud formation, enlargement, and flowering, phosphorus fertilizer or a mixed fertilizer mainly based on phosphorus is needed. In autumn and winter, a mixed fertilizer mainly based on phosphorus and potassium is most suitable.
1. Nitrogen fertilizer to promote spring shoots
Camellias generally begin to sprout spring shoots at around 18°C. At this time, apply a bud-promoting fertilizer mainly based on nitrogen, once every 10 days, until the spring shoots begin to lignify. If conditions permit, a diluted liquid mixed with 1000 times monopotassium phosphate, about 1% urea, and about 300 times rice vinegar can also be sprayed on the leaves at the same time. After repeated root and foliar spraying, the spring shoots will grow very luxuriantly, the leaves can expand to the maximum extent, and the branches and shoots can accumulate rich nutrients, creating good conditions for flower bud differentiation.
2. Increase the application of phosphorus and potassium fertilizers to promote flower bud differentiation and form flower buds
After the spring shoots of camellias have fully sprouted and entered lignification, there will be a relatively short semi-dormant period. At this time, camellias shift from the vegetative growth stage to reproductive growth, and flower buds begin to differentiate. If you want camellias to produce more buds, apply more phosphorus and potassium fertilizers, and do not apply or apply less nitrogen fertilizer. If a small camellia plant is mainly being grown to develop its overall size, then still mainly apply nitrogen fertilizer, and do not apply or apply less phosphorus fertilizer. About every 10 days, spray the leaves with a diluted liquid mixed with 1000 times monopotassium phosphate, a small amount of borax, and rice vinegar. This can not only control excessive spindly growth of camellia branches, but also promote and shorten the time of flower bud differentiation, which is beneficial to flower bud formation.
3. Do not fertilize in midsummer, and especially do not apply concentrated fertilizer
In midsummer, the weather is hot, and camellias grow slowly or enter a semi-paused state. At this time, it is not suitable to fertilize, and special care should be taken not to apply concentrated fertilizer. If the soil is poor and thin, a slightly diluted liquid fertilizer can be applied along with watering to improve the soil.
4. In autumn, appropriately apply a mixed fertilizer mainly based on phosphorus and potassium
In autumn, the sky is high and the air is crisp, which is a period of nutrient accumulation for camellia plants. In order to overwinter safely, a mixed fertilizer mainly based on phosphorus and potassium can be applied once every half month, combined with foliar spraying, to promote strong plant growth and improve the cold resistance of camellias.
5. In winter, apply diluted phosphorus-potassium liquid fertilizer
In the cold winter, camellias enter a semi-dormant period. When camellias are moved indoors or into storage, vegetative growth has entered dormancy and not much fertilizer is needed. However, reproductive growth has not completely stopped, and it is in the season of flowering or preparing to flower, so diluted phosphorus-potassium liquid fertilizer should be applied along with watering. Never apply concentrated fertilizer.
Precautions:
1. Camellias like cool weather and fear high temperatures and heat. When topdressing after the beginning of spring, alum fertilizer water must be watered on. To make alum fertilizer water, add 100 g of green [ferrous sulfate] to 10 kg of clear water, then add 200 g of soybean cake powder and 1000 g of dried poultry manure and soak to ferment. In hot weather, soak for 1 month; in cool weather, soak for 3—4 months until fully decomposed.
2. Do not apply excessive fertilizer, and do not apply concentrated fertilizer. This is because camellias do not like concentrated fertilizer; otherwise it will damage the root system and reduce the number of flowers. For the base fertilizer of camellias, it is best to use organic fertilizers, such as fermented chicken and duck manure, animal organs, soybean cake, fish bone meal, and so on. These organic fertilizers contain nitrogen, phosphorus, potassium, and other components, are relatively comprehensive, and have a long fertilizer effect. When applying, they can be sun-dried, crushed into powder, first mixed with 5—6 times the amount of dry soil, and then sprinkled 2—3 cm away from the plant roots when repotting and filling the potting soil.
3. It is best to base fertilization mainly on phosphorus fertilizer, with nitrogen fertilizer as a supplement. In addition to applying base fertilizer when potting or repotting, topdressing should preferably be applied in April after flowering, in June, and in October. Only thin fertilizer should be applied, and it is best to make it into alum fertilizer water. Too cold or too hot is unfavorable to the growth and development of camellias. In winter, the indoor overwintering temperature should preferably be kept at 3-4°C. In the high-temperature seasons of summer and autumn, shade and cooling should be carried out in time, while in spring and the plum rain period, sufficient sunlight should be provided.