If the water is insufficient, the leaves of rhododendron will turn black due to drought, especially the young leaves. However, if the roots rot due to excessive watering, its young leaves will easily turn black because they can't get the water and nutrients needed for growth.
Reasons for the blackening of Rhododendron leaves
Although the main purpose of Yingshanhong bonsai is to watch flowers, if the leaves appear black, it will inevitably affect its ornamental value. At the same time, black leaves are also dangerous signals released when plants have growth problems. The reason is that the black leaves of Yingshanhong are mainly caused by these two factors, namely improper water and fertilizer or improper illumination.
Treatment method of rhododendron blackening
Rhododendron leaves turn black and dry, usually because of poor maintenance. If it is because of too much watering, it is necessary to wait until the soil is dry before watering, and the rotten roots need to be pruned. If the air is dry, spray water on the leaves to keep them moist.
If it is due to strong light, it needs to be maintained under scattered light to maintain a ventilated environment. If it is because of pests and diseases, it needs to be pruned in time, burned centrally and treated with chlorothalonil.
1. When the leaves have turned black, the necrotic parts should be treated in time, properly watered at ordinary times, and then watered when the soil is dry.
2. Fertilization should follow the principle of "thin fertilizer and diligent application", and the fertilizer concentration should not be too high. A small amount of dilute liquid fertilizer can be applied before flowering, and an appropriate amount of topdressing can be applied after flowering.
Do you want to cut the black leaves of azalea?
When the leaves of Ardisia rhododendron turn black, they need to be trimmed in time and then put on the pot again. Pay attention to keep the soil moist when putting the pot, and don't pour water after putting the pot. If the temperature is lower than 15℃, it will take about 10 days to wrap the aboveground parts with transparent plastic bags, so the leaves should grow again.