In family gardening, flower lovers are not only concerned about watering, but how to fertilize is also very important. Personally, I think that family fertilization should follow a general principle, that is, "apply less fertilizer, apply thinner fertilizer more." Speaking of fertilization, we must first understand the types and functions of fertilizers. 

The basic nutrients of flowers are the three elements of nitrogen, phosphorus and potassium:
1. Nitrogen fertilizer: It can promote the flourishing of branches and leaves and increase the rate of flowering. Common nitrogen fertilizers include manure and ammonium sulfate.
2. Phosphate fertilizer: It can make the color of flowers bright, firm and full. Common phosphate fertilizers include rice bran, fish scales, bone meal, chicken manure, superphosphate and so on.
3. Potassium fertilizer: It can make the root system grow strong, enhance the resistance of flowers to pests, cold and heat, and increase the fragrance of flowers. Common potassium fertilizers include rice straw ash, plant ash, potassium sulfate and so on.

In addition, the habits of plants are divided into fertilizer-loving plants and barren-tolerant plants, such as citrus, nandina, pomegranate and other fertilizer-loving plants should be fertilized more; while rhododendron, black pine and other barren-tolerant plants should be applied thinner fertilizer. Rhododendron has small roots and weak ability to absorb fertilizer. Too much fertilizer will cause damage, and too little fertilizer will affect flowering.

During the growth period of the plant, apply more self-made fertilizer water and bean cake fertilizer water, and watering at the same time; remember not to use a fixed type of fertilizer, it should be properly matched and applied in turns.

In the bud stage of plants, phosphate fertilizer is the mainstay, bone meal water is mostly used, and a small amount of potassium dihydrogen phosphate or plant ash water is used.

During the flowering period of the plants, the fertilizer is mainly potassium fertilizer. You can use more plant ash soaked water for irrigation, and apply a small amount of potassium dihydrogen phosphate fertilizer.

In family flower cultivation, it is common to buckle residual tea, eggshells and even watermelon peels directly on the pot soil when planting flowers and trees in some families, hoping to increase the fertility of the pot soil. In fact, this method is not scientific. Residual tea is prone to mold and smell, pollutes indoor air and is unsightly. Excessive humidity can attract anaerobic microorganisms, bacteria and insects to gather and multiply. The eggshell buckle on the pot soil is unsightly, and at the same time, the remaining egg white flows into the surface of the pot soil, directly clogging the capillary tube, affecting soil ventilation and root respiration. In addition, hydrogen sulfide gas will be produced after the egg white is fermented, which smells bad, pollutes the indoor air and attracts flies. As for the watermelon rind, some people say that it can reduce water evaporation, both as a water source for potted flowers and as fertilizer. In fact, watermelon rind quickly becomes rancid in hot and humid weather, sour and smelly, and it also attracts flies. Therefore, do not directly cover the soil of the flowerpot with residual tea, eggshells, or watermelon peel. These things can be mixed and composted with garden soil before use.