How to Water and Fertilize Azaleas? A Detailed Guide to Water and Fertilizer Management

Azaleas prefer slightly acidic water and dislike saline-alkaline water; river water and rainwater are best for watering. When using tap water, it must be stored for more than 12 hours before use. For households growing just a few azaleas, water from a goldfish tank can be used, as it contains nutrients that benefit azalea growth. Water in northern regions has some alkalinity, so ferrous sulfate can be added to adjust the pH value. When watering azaleas in winter, the water temperature should be close to the soil temperature, and the difference should not exceed 2°C. Azaleas are shallow-rooted plants, so watering should follow the principle of "water when dry, not when wet; do not water unless dry; water thoroughly when you do." As for the amount and frequency of watering, it should be properly adjusted according to the different growth stages of the azalea and in combination with climate changes. Generally, watering azaleas is divided into five stages:

(1) Dormant period, from November of the current year to February of the following year, when azaleas need very little water. Those cultivated in a greenhouse can be watered once every 45 days.

(2) During March, azaleas begin to root and sprout, and their water needs increase accordingly. Generally, on sunny days, water once every 1 to 2 days.

(3) From April to August, during the period when azaleas bloom and sprout new shoots, growth is vigorous and water demand is relatively high. On sunny days, water once a day, and in some cases add supplementary water in the evening. During the day, spray water on the leaves and ground. During prolonged rainy days, promptly drain accumulated water from the pots to avoid root rot.

(4) From July to early September, water once every morning, and spray clean water on the leaves and ground at noon to maintain a humid environment. In the afternoon, pay attention to "checking for water" to prevent "leaf drop."

(5) From mid-September to October, azalea new shoots stop growing and flower buds begin to differentiate. The potting soil should be slightly dry, and generally water once every 2 days in the morning. For topdressing azaleas, decomposed liquid fertilizer is best. After being moved outside until before the flower buds show color, phosphorus fertilizer should be the main topdressing, applying fishy water once every 10 days at a concentration of 10%, for a total of 2 to 3 applications. Fishy water is rich in phosphorus and nitrogen, which can make azalea flowers larger, better colored, with thicker petals and a longer flowering period. During the flowering period, topdressing should be stopped; otherwise, flowers will drop and leaves will grow, failing to meet ornamental requirements. After flowering, nitrogen fertilizer should be supplemented to help the plant recover and promote new shoot and leaf growth. From mid-May to early July, apply cake liquid fertilizer 5 to 6 times at a concentration of 10%. If it rains continuously, fine crushed cake fertilizer can be applied. First loosen the potting soil, then scatter the cake fertilizer around the edge of the flowerpot, cover it with a layer of soil, and afterward let it seep into the soil with watering. Before azaleas are moved indoors in late autumn, in order to supply the fertilizer needed during the bud-growing period, apply 1 to 2 times decomposed cake fertilizer powder and bone meal dry fertilizer, place it on the pot surface, and cover with a layer of potting soil. In winter, when they enter the dormant period, fertilization is not suitable.