Why do rhododendrons leaves turn yellow

Other causes include improper irrigation, inadequate lighting, faulty watering schedule, insufficient nutrient supply, and disease. When it comes to growing the Rhododendron plants, they are mostly hassle-free; however, occasionally, the plant may create some problems for the owner. It is usual for most plants to lose their characteristic color when faced with excess or shortage of food or water.

Some common causes for Rhododendron plants leaf yellowing include the following:. The Rhododendron plants are generally tolerant; however, they are quick to react when their soil pH rises above normal. The Rhododendron plants thrive in slightly acidic to neutral soils.

Therefore, when the soil becomes too alkaline, the plant develops yellow leaves. In alkaline soils, the Rhododendron plants soak up excessive amounts of calcium and insufficient iron.

If the pH is too high or too low, consider replacing the old soil with fresh, nutritious soil or thoroughly wash out the current soil. Most plants, including the Rhododendrons, are sensitive to their watering routines and water characteristics. In the case of the Rhododendrons plant, the leaves do not like to be directly sprayed. They may also turn brown or form necrotic crispy spots on them.

If cold water is given persistently, the Rhododendron plant might even die. Unfortunately, you cannot save the damaged, yellow foliage. However, you can check your water temperature before watering in the future. For the best results, I suggest using lukewarm water only.

Like most plants, the Rhododendron plant prefers bright, dappled sunlight. Therefore, when placed in a poorly-lit room with insufficient aeration and a congested space, the plant may respond by turning its leaves yellow. Maintaining a steady balance between the two extremes of excessive and partial sunlight is necessary to nurture a healthy Rhododendron plant.

I recommend putting your Rhododendron plant in an airy, brightly lit room that receives ample filtered sunlight. Often, northeast and west-facing windows offer just the right amount of sun for most flowering species. When the soil pH is too high too alkaline for acid-loving rhodies, some nutrients are tied up in the soil and unavailable to the plant.

If you fertilize with an acidic fertilizer, widely available in the garden section of your local store, then the leaves green up. Other symptoms may plague rhododendrons this time of year.

Pale green or dwarfed leaves indicate a lack of nitrogen. Yellow mottling along the leaf margins may indicate an excess of potassium. If the leaves are smaller and darker green than normal and the tips are dead, your shrub may need phosphorus. Past weather conditions may be contributing to your bushes' physical symptoms. Leaves can be discolored from hot sun or winter frost.

Also, as the interior leaves of the plant are shaded out, they may turn yellow and drop off, which is a normal process called senescence. We've had quite a dry spring. Are your rhodies planted under an eave? They may need a good deep watering. With shallow, fibrous root systems, rhododendrons and azaleas need ample water during the summer as well. It is better to water them deeply and infrequetly, than often and shallowly. Rhododendrons with yellow leaves are most likely suffering from chlorosis, or a lack of chlorophyll, according to Purdue University.

Chlorophyll is the pigment that gives plants their green color and allows them to capture light for photosynthesis.

Leaves affected by chlorosis show yellowing between dark green veins rather than a uniform yellow color. The youngest foliage is the first to show damage, and the entire plant may eventually be stunted or fail to produce flowers. In severe cases, the plant may die. Most commonly, chlorosis is caused by a lack of iron, but it can sometimes also be caused by a lack of manganese, nitrogen or zinc. Rhododendrons thrive when the soil pH is between 4. You can check the pH with a home test kit or send a sample to your local extension.