Yellow Leaves on Rhododendrons – How to Cure

Rhododendrons are perennial shrubs that beautify our gardens. If you notice yellow leaves on rhododendrons, there may be a problem. Do not worry, this has a solution, but the first thing is to know why the rhododendron has yellow leaves. In this article, we will explain how to solve the problem of yellow leaves in rhododendrons.

What Causes Yellow Leaves on Rhododendrons

Yellow leaves on rhododendrons can be caused by several factors, for example, it can be a problem of excess water or lack of water. Also, if the plant suffers some kind of stress that may cause yellow leaves, the main thing is to know how to differentiate what the problem is so we can then start the appropriate treatment and thus save our rhododendron plant.

Yellow Leaves on Rhododendrons Due to Excess Light

It is one of the most important rhododendron cares. Although it needs good sun exposure, it does not tolerate direct sunlight. Rhododendrons thrive best in semi-shade or, failing that, in a site that receives sunlight during off-peak hours.

Rhododendron leaves turn yellow due to sun exposure, sunlight tends to discolor exposed leaves. When this happens, adding nitrogen helps the leaves turn green again.

To avoid this problem, we must choose the right place to plant our rhododendron, this can be in a place with some shade or where it gets sunlight at off-peak hours.

yellow leaves on rhododendrons excess to light

Extreme Temperatures the Enemy of Rhododendrons

The excess of cold or heat is something that we will have to consider seriously in the care of the rhododendron. Although it is not a demanding plant in terms of climate and is easily adapted to them, it is necessary to be vigilant if we live in a place of extremes.

But make no mistake. Rhododendron is part of the list of cold-hardy shrubs for the garden. However, you need to be cautious and plant it sheltered from frost. If this is not possible, simply mulch it with mulch or dry leaves during the harsh winter months.  Prevention is better than having to figure out how to recover a plant after a frost.

Yellow Leaves on Rhododendrons Due to Excess Water

Just as we will have to take time to decide where to plant it, spending a little more time on drainage is essential. Despite being a water-loving plant, the rhododendron does not tolerate excess water in its roots. What’s more, exposing it to that extra water will only result in the death of the plant.

Without good drainage, you will have yellow leaves on rhododendrons, make sure the soil is adequate and if it does not have good drainage, you can add clay pellets or perlite to improve it.

yellow leaves on rhododendrons excess to water

Acid Soil, One of The Rhododendron Care Vital for Its Development

A detail is even more important than the planting site. Only if we provide our shrub with acid soil will it be able to grow healthily and, more importantly, bloom. The rhododendron can only unfold its flower clusters if it has the ferric nutrients it needs to do so.

If we do not know the composition of the soil, we can form the pH that this plant needs. Regular inputs of natural fertilizer or mineral fertilizers will suffice. This last step is very important because otherwise, we will have yellow leaves on rhododendrons.

Yellow Leaves on Rhododendrons Due to Chlorosis

When the leaves are yellow but the region along the veins remains dark green, the plant is probably suffering from chlorosis, which is caused by a deficiency of magnesium, nitrogen, or iron. In this case, the pH of the soil should be checked. A very high pH hinders the plant’s ability to absorb the necessary trace metals. If the pH is close to 5.5, it is recommended to add Epsom salts. If this does not work, it is useful to add a source of nitrogen and chelated iron.

Chlorotic leaves are often a sign of iron deficiency and can be treated by using an iron sequence. Overfertilization should be avoided, as the leaf margin will likely become dry and brown.

rhododendron chlorosis
About Henry Morgan

We are the Morgan family, Henry, and Morgan, both agronomists from the University of Michigan, where we met. We are experts in putting our hands in the soil and developing organic foods and improving production processes for decades. Likewise, we have worked for companies such as Mondelez International, BASF, Monsanto, etc. currently in our role as science writers for as well as advisors in promoting large scale food growing in urbanized areas. In this website, we share what we are most passionate about, gardening and farming. Enjoy and see real photos on our website.