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Why Is My Rhododendron Turning Yellow? | 7 Alarming Reasons!

Rhododendrons provide an outstanding aggregate of colorful flora and dark-colored leaves.

However, from time to time, the leaves may lose their color for many reasons.

This article explains and answers to: why is my Rhododendron turning yellow?

Yellow Rhododendron leaves frequently constitute the plant’s expression of dissatisfaction with its care. If you notice your rhododendron leaves turning yellow, assess every detail of the plant’s care.

A critical reason for leaves turning yellow is inaccurate soil pH because the Rhododendron flora is prone to modifications of their soil contents. Other reasons include mistaken irrigation, insufficient lighting, defective watering schedule, inadequate nutrient supply, and disease.

Why is my Rhododendron turning yellow, you ask? Wanna know?

Let’s dive in!

Yellow leaves on Rhododenderon—why is my Rhododendron turning yellow
Why is my Rhododendron turning yellow? – Image via Reddit.

Why Is My Rhododendron Turning Yellow?

Here’s a list of possible problems with your Rhododendron:

1. Moisture

Poorly draining soil or parched soil can both cause Rhododendrons to turn yellow.

  • Check how nicely your soil drains.
  • This shrub doesn’t do nicely in moist soil, and extra moisture can be why leaves turn yellow on Rhododendron.
  • Let the soil dry, and watch how speedy the water soaks into the soil.
  • If the drainage is bad, try transporting your plant to a location with relatively less moisture or make an appropriate potting mixture according to the nature of your plant.

Let’s talk about pH.

2. pH

Test your soil’s acidity with a domestic pH tester.

Why is my Rhododendron turning yellow, you say? If your soil is alkaline, you’ve discovered a cause—this indicates a mineral deficiency inflicting chlorosis.

These shrubs take in excessive calcium and now no longer have sufficient iron in alkaline soils.

Chlorosis could be possible while the yellowing is frequent among the veins of recent leaves.

Although acidifying the soil with sulfur is far from feasible, transplanting the shrub to a raised mattress is probably the first-class and fastest method to treat Rhododendron leaves turning yellow from chlorosis.

3. Watering

One of the most probable reasons for yellowing the Rhododendron leaves is a wrong watering schedule.

Most flora, such as the Rhododendrons, are touchy with their watering exercises

  • In the case of the Rhododendrons, the leaves do not want to be sprayed directly.
  • The best way to water a rhododendron plant is to moisten the environment or water the soil only.
  • When given excessive water, the Rhododendron plant’s leaves react by growing yellow shades. They can also change their color to brown or crispy spots might appear on them.
  • Another significant cause can be irregular water temperature.
  • Water whose temperature differs significantly from the plant’s temperature may cause a shock to the plant.
  • It can even result in plant death if given repeatedly.
  • Therefore, use room-temperature, low-chlorine water to water your plants.
  • Harmful factors such as over and underwatering can result in root rot and crisp, dry leaves, respectively.

Therefore, making a perfect watering schedule for your plant would be best. Just make sure to keep the schedule flexible for different weather.

4. Lighting

Rhododendrons prefer bright daylight for maximum growth.

Too much or too little sunlight effortlessly affects the leaf color.

Therefore, while located in a poorly-lit room with inadequate aeration and crowded space, the plant may also reply by turning its leaves yellow.

Similarly, the Rhododendron may flip yellow while positioned indoors with direct, sizzling sunlight.

Maintaining regular stability among the extremes of immoderate and partial daylight is vital to nurture a healthy Rhododendron plant. Placing your Rhododendron plant in an airy, brightly lit room with adequate filtered daylight is preferred the most.

5. Improper Fertilization

So, why is my Rhododendron turning yellow?

Another primary reason for the Rhododendron plant leaves turning yellow is improper fertilization.

  • The yellow leaves may also indicate that the plant desires more nutrients.
  • A good fertilizer is vital for any plant’s healthy development—get a slow-launch excellent fertilizer made especially for Rhododendron flora.
  • Another choice is to apply a diluted liquid fertilizer. Spread the fertilizer lightly over your plant’s soil a few times a month, or observe the product packaging guidelines.
  • Alternatively, your Rhododendron plant may turn yellow if it can’t take in the furnished feed efficiently.
  • When confronted with one of these difficulties, practice fertilizer on the soil while it’s moist; this guarantees the most absorption.
  • As much as you recognize your Rhododendron plant’s needs, fertilizing it over and over can also cause several problems, one of them being yellow leaves. The Rhododendron plant is huge; however, feeding it time and again isn’t an excellent idea.
  • To save your plant from salt buildup, keep it away from overfertilizing.
  • For fertilizing, use good quality feed once a month only.

Now you know everything you need to know about fertilizing your Rhododendrons.

6. Repotting

The Rhododendrons are decently-sized flora with a little boom rate.

Repotting it every year isn’t essential. However, it typically desires to be repotted every two to three years.

A plant’s soil may lose its herbal texture and nutrient content because it ages. Growing the Rhododendron plant in one of these soil blends can retard its blooms because it can’t uptake sufficient nutrients and water.

After about two years, repot your Rhododendron into a slightly larger pot with the perfect soil blend—the potting mix needs to preferably incorporate pine bark, peat moss, and a little sand.

So if you haven’t repotted your rhododendrons plant in years, the yellowing of leaves is the sign!

7. Pests and Diseases

The most common problem that your plant might be fighting is the presence of pests and diseases.

The yellowing of plant leaves indicates that your plant needs your attention as it might be in danger.

If you notice any spider mites, aphids, mealybugs, or other foreign vermin, spray some horticultural sprays, neem oil, or insecticides (in severe cases) to save your plant from being sucked by the pests.
Houseplant Pests: Get Rid of Them Organically! – YouTube

That’s all for today!


Every plant grows in different conditions.

Why is my Rhododendron turning yellow? The yellowing of leaves of a rhododendrons plant can be an indication of a list of problems. Read the article carefully to get all your knowledge about why your Rhododendron is turning yellow.

Without panicking, try to find out the possible problem that your plant might be facing. Once you have passed the identification stage, you can focus on treating your plant so it can recover in no time.

Good luck!