Key points of soilless cultivation of rhododendron

1. The root system of rhododendron is very slender, which requires loose matrix to facilitate air permeability and drainage. 1 part of vermiculite, 1 part of pearl sand, 1 part of river sand and 1 part of cinder were mixed in proportion. After mixing the substrate, sterilize it with 0.1% carbendazim solution, mix it evenly into the substrate and cover the plastic film for 1 day. Then rinse with clean water for many times, dry, mix well with 0.4% agricultural compound fertilizer solution, then cover it with plastic film for a month, and then use it in the basin.

2. The preparation of nutrient solution Rhododendron has strict requirements for fertilizer. During the growing period, thin fertilizer is applied diligently. According to the experiment, good results can be obtained by using agricultural compound fertilizer mainly, supplemented with trace elements, pH value controlled at about 5 and spraying low concentration foliar fertilizer. The preparation of a large number of elements: 1 liter of water plus 2 grams of agricultural compound fertilizer, plus 0.5 grams of magnesium sulfate, as the standard solution. The preparation of trace elements: 1 liter of water plus 20 grams of disodium ethylenediamine tetraacetate, 15 grams of ferrous sulfate, 4 grams of manganese sulfate, 6 grams of boric acid, 0.2 grams of zinc sulfate, 0.1 grams of copper sulfate and 0.2 grams of ammonium molybdate as mother liquor. When in use, 1 liter of standard liquid and 1 ml of trace element mother liquid are all elements. The preparation of foliar fertilizer: 1g urea, 1g potassium dihydrogen phosphate, 0.02g boric acid and 10.1g vitamin B in 1 liter of water.

3. Water and fertilizer management due to the good drainage and air permeability of the substrate, but poor water retention, so the amount of water is generally more than that of soil culture, in order to keep the substrate moist. When pregnant buds and leaf buds germinate, a large amount of fertilizer is needed, and the full amount of nutrient solution is irrigated once in about 10 days, and foliar fertilizer is sprayed once in 15 days from March until the buds burst. After flowering, there is a large amount of water, in addition to watering every day, foliar watering should be carried out in the evening. At this time, the amount of fertilizer is also large, so it can be changed to irrigate the nutrient solution once a week and spray foliar fertilizer once a week to promote the sturdiness of new branches and facilitate flower bud differentiation. After ambushing, pay attention to keep the substrate moist, and sprinkle water to the leaf surface, the amount of fertilizer can be reduced to about 20 days to pour nutrient solution once. After the autumn is cool, you can gradually increase the amount of fertilizer, apply the full amount of nutrient solution once in half a month, and spray foliar fertilizer twice to promote the healthy growth of flower buds. After the beginning of winter, the physiological activity of rhododendron is weak, so it is not suitable to apply fertilizer, but can be watered properly according to the dry and wet degree of the substrate.