How to raise azaleas in the north

Rhododendron is one of the representatives of acidophilic plants, with the best pH value from 5.5 to 6.5. it likes the cool, humid and well-ventilated environment, the suitable growth temperature is 13 ℃ to 25 ℃, and the air relative humidity should be maintained from 60% to 70% during the growing period.

Cuckoos like light, but avoid strong light, increase shading appropriately in spring and autumn, reach about 70% shading in the middle of summer, and often spray water on the leaves to moisturize and cool down, and cuckoos should be kept outdoors in summer to facilitate ventilation. Cuckoos like light fertilizer, but avoid thick fertilizer, thin fertilizer should be applied frequently during the growing period, preferably farm manure, such as bean cake water, horseshoe palm water and various vegetables, chicken feathers, fish offal and other sundries after soaking and fermenting liquid fertilizer can be applied. Cuckoo is a whisker root, slender and weak, so can not use heavy clay, like loose, permeable, breathable acid soil, the north can use muddy mountain, larch leaf soil, or artificial culture soil and other rotten leaf soil. The flowers should be pruned in order to make the flowers more beautiful and control the flowering period, and the cut annual branches can also be cut and propagated.

If rhododendron has yellow leaves on the front and red insect spots on the back, it is harmful to red spiders, and serious leaves will fall. It can be sprayed with 1000 times trichloroacarol, once every seven days, and can be removed three times in a row. If the leaves are yellow and the veins are still green, it is a symptom of iron deficiency, the ferrous sulfate solution can be sprayed once in about ten days, and the concentration is not more than 5 ‰. Vinegar and fermented rice washing water also have a certain effect. In addition, there are other symptoms such as: the leaves are not glossy, the reddish brown dry tip is gradually enlarged, which is caused by strong light, poor ventilation and high temperature, which can improve the environment for prevention and treatment. If you get brown spot, you can use chlorothalonil, carbendazim, carbendazim, methyl topiramate and other prevention and control. There are leaves yellow or still very green, but gently touch the branches, the leaves will fall, and soon fall light, this is the light is too dark, stuffy; the light is too weak, the air is too dry, air pollution caused by the prevention and control. When the cuckoo is short of water, it wilts and droops, and the yellow new leaves are caused by long-term water bubbles. If the leaves wilt, but they are still green and not easy to fall, some are also caused by large water. Leaves have uneven size or patches of black spots, mostly caused by black spot disease, caused by bacteria, mostly caused by large water, poor ventilation and weak light, which can change the environment and drug prevention and treatment.