What kind of fertilizer is suitable for azaleas?

Azaleas are fertilizer-loving plants and, in addition to the main nutrients nitrogen, phosphorus and potassium, they also need trace elements such as boron, copper, molybdenum and zinc. Azaleas do best with fertilizers that are gentle and long-lasting. For home azalea growing, you can use horn, ram's horn and animal hoof pieces; these fertilizers contain 12%-15% nitrogen, 0.2%-8% phosphorus, and also a small amount of potassium and trace elements. Thin hoof pieces take effect 1 month after application, while thick hoof and horn pieces show their fertilizing effect after 2 months, and the fertility can last 6-8 months. When using them, you can bury the hoof pieces and so on around the edge or at the bottom of the pot while repotting or moving the plant into another pot. Cake fertilizer is also a fairly complete fertilizer in terms of nutrients. The nutrients in cake fertilizer generally contain 2.1%-7.6% nitrogen, 0.54%-3.3% phosphorus and 0.5%-2.7% potassium. Generally speaking, soybean cake and peanut cake contain more nitrogen, while rapeseed cake and cottonseed cake contain a bit more phosphorus. They must be fully fermented before application. Fertilizer made by composting livestock manure and tree leaves can be mixed into the growing medium when repotting.

Different azalea varieties also differ in their fertilizer requirements. Among the azalea varieties in Dandong, Sihaibo, Shuanghuahong and Hamudan need a little less fertilizer; Xiannüwu, Wubaozhu and Fuguji are relatively tolerant of fertilizer; and large-leaved azaleas and others are even more tolerant of fertilizer.

Azalea fertilization should follow the principle of applying lightly and frequently. Fertilization is generally carried out during the vigorous growth periods in spring and autumn, and generally no fertilizer is applied in winter. For flowering plants, apply hoof pieces or manure once when repotting in March or April in spring, apply soybean cake or hoof and horn fertilizer solution 1-2 times in May and June, and in the rainy season the well-fermented cake fertilizer powder can be scattered on the pot surface and mixed evenly with the topsoil. In autumn, apply one more relatively concentrated liquid fertilizer. Generally, for a flower pot with a diameter of 20 cm, a vigorously growing plant uses about 100 grams of soybean cake fertilizer over the whole year.