Why are the leaves of rhododendrons turning yellow?

Rhododendron is a relatively common flower variety and one of the top ten flowers in our country, with a large number of growers. If problems arise during cultivation and cause the rhododendron leaves to turn yellow, it will seriously affect the ornamental value of the rhododendron, but for beginners, when faced with yellowing rhododendron leaves they often become at a loss and randomly take some measures. So what exactly is going on with rhododendron leaves turning yellow? Below, Qinnong Web will introduce it to everyone.

1. Causes of rhododendron leaves turning yellow

First let us understand the causes of rhododendron leaves turning yellow. Qinnong Web has summarized four points here for everyone, all of which are issues we often overlook in our daily care process. Let us take a look together below.

1. Soil tends to be alkaline

The soil and water in northern China contain relatively more alkali, while rhododendrons need to grow in a relatively acidic environment. In addition, if the water lacks soluble iron, rhododendrons are prone to yellow leaves. The best solution is to add ferrous sulfate solution or granules to the soil. This can both supplement iron and make the soil relatively acidic, achieving two goals at once.

2. Improper lighting

Rhododendrons like a cool and shady growing environment, but if they are placed in a shaded place without light for a long time, or if the light is too strong, the branches and leaves of the rhododendron will grow leggy, the leaves will be thin and yellow, and it will not bloom or bloom only a little. At this time, it is necessary to promptly move the rhododendron to a sunny place or a shady place for cultivation. It is best to give the rhododendron a fixed time for sun exposure.

3. Excessive stimulation

Plants, like animals, cannot be subjected to strong stimulation. Of course, the stimulation here does not refer to fright and similar stimulation, but rather stimulation that can affect plants, including excessively high concentrations of pesticides for pest and disease control, sudden temperature changes, and so on, all of which can cause the leaf tips or parts of the leaf surface of rhododendrons to turn yellow and scorch. Therefore, during cultivation, pesticides should be used reasonably, unnecessary air pollution should be reduced, and in seasons with changeable temperatures, attention should be paid to giving rhododendrons a relatively stable temperature for growth.

4. Temperature effects

The suitable growth temperature for rhododendrons is 15~25°C. In winter, temperatures above 10°C allow them to overwinter safely. But winter weather is changeable. If they are not moved indoors in time or are directly exposed to cold wind, rhododendrons are very susceptible to cold damage, leading to yellow leaves, and in severe cases they may wither, turn yellow, and die. Therefore, move rhododendrons indoors for care in mid-October each year, place them in a sunny spot, and control the room temperature at around 10°C.

2. How to prevent rhododendron leaves from turning yellow

Actually, it is relatively difficult to completely prevent rhododendron leaves from turning yellow, but we can try our best to provide rhododendrons with a suitable growing environment to reduce the possibility of yellow leaves. In addition to the points mentioned above, Qinnong Web also has two more things to tell everyone here: the first is to repot in time, repotting once every two years, and usually only 1/3 of the soil needs to be replaced. This can both renew the nutrients in the soil and avoid excessive changes in the soil environment that affect plant growth; the second point is to promptly prune diseased branches and weak branches, which can not only promote plant growth, but also ensure a perfect plant shape and reasonable branch distribution.

The above is what Qinnong Web has introduced for everyone regarding the causes of rhododendron leaves turning yellow and the solutions, hoping to bring everyone some help. The rhododendron has a peculiar shape and is an excellent bonsai material. It is also a Chinese medicinal herb with the effect of promoting blood circulation and relieving pain, and it also has certain economic value and edible value. It is a multipurpose flowering plant.