How to grow potted azaleas? A complete guide to cultivation techniques

The potted method for azaleas is not hard to improve. As long as you master the skills, you won't be afraid to grow a good pot of azaleas. Below, the editor introduces the cultivation techniques and pest control methods for potted azaleas. I hope everyone enjoys them.

Cultivation techniques for potted azaleas

1. Soil: Potted azaleas should be planted in loose, humus-rich acidic soil. Planting azaleas should ensure the potting soil is humus-rich acidic soil and that the soil is loose, breathable and well-draining. Clay or alkaline soil should not be used. The pH of the acidic soil should be controlled between 5.5 and 6.5.

2. Temperature: Potted azaleas should be kept at indoor temperatures. Different azalea varieties have different temperature requirements, but most azaleas prefer a warm environment, with a suitable temperature between 15°C and 28°C. In winter, the room temperature generally should not be lower than 10°C. When the temperature is too high, azaleas will stop growing, so in summer it is easy to place them in a cool, ventilated spot, and in winter they should be placed indoors. If necessary, the indoor temperature can be increased to prevent freezing damage.

3. Watering: Potted azaleas should be watered more during the flowering period and in summer. Azaleas like a humid environment. During the flowering period from April to June, sufficient moisture should be maintained, and they should be watered once a day in the evening. When the summer climate is hot and dry, because of water evaporation, they should be watered once a day. In spring and autumn, water once every 4 days. In winter, azaleas enter dormancy and watering should be reduced.

4. Sunlight: Potted azaleas should not be exposed to excessive sun. Azaleas should not be exposed to direct sunlight; when placed in the sun, some shading should be provided to prevent the branches from burning, but the specific light should also change with the seasons. For example, in spring and autumn, the sunlight is not strong, so about 20% shading is given; if it is the flowering period and summer, give 60% shading.

5. Water quality: Potted azaleas are better watered with natural water. Better natural waters include fish tank water, rainwater, pond water and river water. Usually, some "hard water" can be stored; stored water is water left to stand with the azaleas at the same temperature for one or two days, so the water can reach the same temperature as the soil and store more nutrients.

6. Fertilizing: Potted azaleas should be given lean fertilizer and fertilized diligently. They like fertilizer but should also avoid over-fertilizing, and each time fertilizer is applied it should not be too much. From February to March, to promote the growth of their branches and leaves, a light fertilizer based on nitrogen and potassium can be applied once every 10 days. April to June is the flowering period, and phosphorus fertilizer should be the main type, supplemented by potassium fertilizer, applied once every 5 days. When the temperature is above 28°C, fertilizing should be stopped. In winter, fertilize less. Daily, apply some fertilizer water or a small amount of ferrous sulfate in the water to maintain the acidity of the soil.

7. Repotting: Potted azaleas should be repotted in time. As azaleas grow, they should be repotted in time so as not to affect growth. Generally, a 5-year-old plant should use a 5-inch pot, and a 7-10-year-old plant should use a 6-inch pot. An 8-inch or longer pot should be used at 8 years. When repotting, some slow-release fertilizer needs to be added.

8. Pruning: Pruning is an important measure in daily maintenance and management work. It can regulate growth and development and make growth vigorous. Daily pruning requires cutting off some diseased branches and fine old branches, and combining some dense branches with crown shaping to increase ventilation and light transmission, which is beneficial to plant growth. For azalea gardens, it is necessary to inspect frequently; if dead branches and diseased branches are found, they should be removed in time to reduce the spread of azalea pests and diseases.

9. Bud picking: The buds of potted azaleas should be picked in time so that nutrients are concentrated and supplied to the flowers. Pruning branches is generally carried out in spring and autumn. Cut off crossing branches, overly dense branches, overlapping branches and weak branches, and remove residual flowers in time. Because of tree shaping, shaping is usually manually modified as needed into a natural tree form.

Azalea pests and diseases and control methods

1. Brown spot disease

[Symptoms] Brown spot disease is a major disease of azaleas. When the disease develops, small brown spots appear on the leaf surface and gradually develop into irregular large spots. Many black or grayish-brown spots form on the lesions, causing the affected leaves to turn yellow and fall off, affecting flowering and the development of flower buds the following year. This disease often occurs during the rainy season when humidity is high.

[Prevention and control] Attention should be paid to letting the plants ventilate and receive light, not making the humidity too high, and increasing the application of organic fertilizer and nitrogen-phosphorus-potassium fertilizer to improve the plants' ability to resist infection and grow. If diseased leaves are found, they should be removed in time and burned in a concentrated way. In the early stage of the disease, spray 0.5% Bordeaux mixture or 0.4 degree lime sulfur mixture, and add 4% flour to increase adhesion. Leaf spot and black spot can also be treated in the same way.

2. Yellowing disease

[Symptoms] Iron deficiency yellowing often occurs where the soil is alkaline. When the condition is mild, only plant chlorosis occurs. In severe cases, all leaf tissues turn yellow and the leaf edges are scorched. When the disease occurs, the leaves at the top of the plant are most obvious, and it is usually caused by internal iron deficiency.

[Control] Change the iron deficiency in the soil and reduce soil alkalinity. Add organic fertilizer to improve clay soil. For iron-deficient plants, an O.2-0.3% ferrous sulfate solution can be sprayed directly. It is also possible to poke some holes 15 cm deep in the soil around the plant, then slowly inject a 10×177b ferrous sulfate aqueous solution, and fill the holes to increase soil acidity and reduce alkalinity.

3. Scale insects

[Symptoms] Adult scale insects are small and flat, about 4 mm long, and black. This is the most serious pest of evergreen azaleas. They often suck leaf sap behind the leaves, and yellow and white spots appear on the leaf surface of the affected plants. The spots cause the leaves to fall off, causing the tree to weaken and affecting growth and flowering. Azaleas in greenhouses are very susceptible to this insect.

[Prevention and control] Spray 90% trichlorfon 1000-fold solution or 40% omethoate 1500-fold solution or 50% chlorpyrifos emulsion 1000-1500-fold.

4. Aphids

[Symptoms] Aphids mainly damage the young leaves of azaleas. In lighter cases, the leaves turn green. In severe cases, the leaves curl, harden and become brittle, cannot absorb nutrients, and flowering is affected.

[Control] Usually, special attention should be paid to overwintering aphids. After winter, spray 5 degree lime sulfur mixture on the plants to eliminate overwintering eggs, eradicate weeds near the flowers, and eliminate the source of insects. During the aphid damage period, add 40% dimethoate or omethoate to 1200 times water, and spray the solution continuously; 3 to 4 times will be effective.

5. Short-bearded bugs

[Symptoms] Short-bearded bugs are one of the important pests of azaleas. They often suck sap near the main veins on the back of the leaves, causing many oily patches to form on the back of the leaves and eventually causing the leaves to fall off.

[Control] In mid-to-late October and early spring, spray 0.5 degree lime sulfur mixture each time, and spray 25% insecticidal water-dispersible agent 500-fold solution.

6. Red spiders

[Symptoms] Red spiders are small in shape but very harmful to azaleas. They are most likely to occur when azaleas are grown in high-rise buildings.

[Control] Manual killing. Chemical insecticides can be sprayed with 5 degree lime sulfur mixture. It can also be used by crushing the juice of walnut leaves, carnation leaves and green stems. After diluting the juice with water, sprinkle with water and dilute with 1000 water. This is also a good method.