1. Environmental conditions: It is best to cultivate azaleas in both indoor and outdoor environments. Indoor environment is used in winter. In the Yangtze River Basin, as long as there are certain lighting and ventilation conditions indoors, heating is generally not necessary. The winter in the north is extremely cold and dry, so it is suitable to cultivate it in a greenhouse with a medium temperature (about 15 ℃). For outdoor venues, used in summer and autumn, it is better to use mud instead of cement. The site should be spacious, ventilated and shady. A shade shed should be built above it, covered with reed curtains or protected by natural tree shade. The light transmittance should be about 30%, and sunset sunlight should be avoided.
2. Pot soil requirements: Rhododendron prefers acidic soil that is loose, highly permeable, well-drained, and rich in humus, with a pH value of 5.0-6.0. If you use clay or alkaline soil, you can get rid of all difficulties. Especially summer cuckoos and cuckoos must be grown in mountainous soil. The mountain soil also needs to be modified. Currently, three types of culture soil are usually used. (1) Mix and prepare 7 parts of mountain soil, 1 part of dry moss clippings, 2 parts of dry leaf humus soil, and 1 part of dry fertilizer. (2) 3 parts of mountain bark soil (topsoil), 3 parts of horse manure, 3 parts of fallen leaves and weeds, and 1 part of human excrement are piled up in layers. After 1 to 2 years, they are screened and set aside. (3) Mix and prepare 3 parts of mountain soil, 3 parts of humus soil, 4 parts of garden soil, and 2 parts of sandy soil, and add 50 grams of sesame paste residue and bone meal to each pot.
3. Flowerpot selection: Flowerpots for cultivating azaleas can generally be either mud pots or purple clay pots, depending on the purpose. Mud pots have good ventilation and water permeability, which is conducive to root growth. Production units use these pots for cultivation. Formed azaleas, especially shaped azaleas, are generally planted in beautiful and elegant purple sand pots for indoor and outdoor display. The purple sand pots have fine texture, rich colors and beautiful shapes, which can double the ornamental value. Purple sand pots are not as permeable as mud pots. When planting, broken tiles (old tiles) should be padded around the pot walls to facilitate drainage. The size of the pot you choose depends on the age of the plant. Generally, 5-inch pots are used for 4-6-year-old plants; 6-inch pots are used for 7-10-year-old plants; and 8-inch pots are used for 11-15-year-old reproductive plants.
4. Improve water quality: It is best to use rainwater to water azaleas, followed by river water and pond water. If you use tap water, it is advisable to store the water for 1 to 2 days to allow the chlorine to evaporate before use. Add 0.2% ferrous sulfate when used, water once every 7-10 days during the growing season, and use it frequently to ensure that the soil is acidic.
5. Fertilizer and water management: Rhododendron likes dampness and should not be too dry. More water is especially needed during flowering. In winter, azaleas have entered a dormant period and do not require much water. Watering is generally done once every 4 to 5 days, preferably around noon on a sunny and warm day. Water appropriately depending on the dryness of the pot soil. In March, as rhododendrons sprout roots and sprouts, their water requirements increase. The growth and development of summer cuckoos is slightly delayed and the amount of watering should be less than that of spring cuckoos. Generally, water moderately once every 2 days in the morning. From April to June, azaleas bloom one after another, and the branches and leaves also begin to sprout. They require a large amount of water. Generally, they should be watered once a day in the morning or evening. During the hot and dry season from July to early September, water once in the morning and once in the evening. The amount of water should not be too much. Spray water on the leaves and ground at noon to maintain a moist environment. From mid-September to November, the weather gradually turns cooler, which is the adaptation period for the growth of rhododendrons. In order to prevent the autumn shoots from being pulled out and enhance the winter resistance, the amount of watering should be reduced appropriately. Generally, water once every other morning to keep it moist. Rhododendron prefers fertilizer, so it is generally irrigated with decomposed cake fertilizer, fish meal, broad beans or milkvetch mixed with water after decay. Avoid using human excrement. After leaving the house and before the flower buds bloom, apply a thin fertilizer with a concentration of 15% every 10 days, and apply it 2 to 3 times to promote the old leaves to turn green and new roots to sprout. After the flowers fade, in order to promote the growth of branches and leaves, fertilize 5 to 6 times from mid-May to early July. If it rains continuously, apply dry fertilizer. Before entering the house and before the growth of azaleas is about to stop, fertilize 1 to 2 times.
6. Outdoor shading: It is better to see more sunlight before leaving the house and before flowering; during the flowering period, short-term shading should be carried out at noon, with a light transmittance of 60%; from June to early July During the plum rains, it is the time when rhododendrons are leafing out and growing branches, so they should see as much sunlight as possible. However, in case of strong sunlight, shade should be provided from 9 am to 4 pm to prevent the new leaves from being burned. From mid-July to early September, provide shade from 8 a.m. to 5 p.m. every day to prevent exposure to the scorching sun. The shading time can be shortened during the autumn growth period after September. Generally, shading can be done from 10 am to 4 pm. After October, it is better to see more sunshine. Then carry out shaping and cut off leggy branches, diseased and weak branches, deformed branches and damaged branches.
7. Pruning and pruning: Rhododendrons grow slowly. Generally, they are allowed to grow naturally. They are only trimmed after flowering and cut off leggy branches, diseased and weak branches, deformed branches, and damaged branches.
8. Prevention and treatment of diseases and insect pests: During the damage period, spray 40% dimethoate solution 1500 times once every 7 days for 3 consecutive times.
The control method for terminal bud leaf rollers mainly relies on manual capture and killing. The larvae or pupae can also be sprayed with 40% Dimethoate EC 2000 times or dichlorvos 1500 times.