When infected with aphids, a large number of green and white bugs gather on the back and tender tips of rhododendron leaves. If the number of pests is small, you can wash them off with water, or hang armyworms around them, or spray a little tobacco water. If the number of aphids is large, it can be sprayed in time and several times in a row.
2. Starscream:
After the red spider appeared on the rhododendron, scattered yellow-green spots appeared on the leaves. It can maintain good ventilation, cut off branches and leaves with serious pests, and spray abamectin, 5-degree sulfur mixture and dichlorvos solution.
3, the army with bugs:
This pest is very harmful to rhododendron, and yellow and white spots appear on the damaged leaves. 90% trichlorfon 1000 times, 40% omethoate EC 1500 times and 50% acetaminophen emulsion 1000- 1500 times can be sprayed.
4. Short-bearded moth:
If you are infected with the short beard moth, you can spray Bomei 0.5 degree sulfur mixture and 25% insecticidal swelling agent 500 times in the middle and late June and early spring March respectively.
Cultivation method of rhododendron
1, lighting conditions
Rhododendrons have a high demand for light. The more sunshine, the more flowers bloom. In spring and autumn, plants enter the vigorous growth period, and they need more than 6 hours of light every day to carry out photosynthesis, produce nutrients and promote flower bud differentiation. It's hot in summer, so you can move indoors.
2. Fertilizer and water management
Rhododendron likes warm and humid environment and needs to be watered every two days in daily breeding. After the temperature rises in summer, the air humidity is increased by spraying leaves and the ground to achieve the cooling effect. Apply phosphorus and potassium fertilizer every half month during the growth period and before flowering to provide sufficient nutrients.
Step 3 trim regularly
Rhododendron has a long growth cycle. After flowering, all residual flowers, yellow leaves, dead branches, diseased branches and overgrown branches can be cut off, which does not consume nutrients, promotes the germination and growth of lateral branches, improves the ornamental value of plants and prepares for the next flowering.