Why Are My Rhododendron Leaves Falling Off? (& How To Fix It)

By | Updated May 13, 2023

Rhododendron plants are popular for their large, showy flowers and evergreen leaves.

However, these plants sometimes experience leaf drop, where the leaves fall off unexpectedly.

There are several reasons why this might happen, including environmental stressors or pest infestations.

Luckily, you can also do several things to fix the problem and bring your rhododendron back to good health.

This article will explore why rhododendron leaves might fall off, as well as some tips on fixing the problem.

What Causes Rhododendron Leaves To Fall Off

There are several reasons why the leaves of your rhododendron plant may be falling off.

Here are some of the most common causes:

1. Overwatering

Overwatering is one of the most common reasons for rhododendron leaves to fall off.

When you overwater your plant, the roots cannot get the oxygen they need, and the leaves will start to turn yellow and fall off.

Rhododendron plants need to be watered about once a week or when the soil is dry to the touch.

If you think you are overwatering your plant, try letting the soil dry out completely before watering it again.

2. Underwatering

Underwatering also causes rhododendron leaves to fall off.

Water is essential for plants; without it, they will start to wilt, and the leaves will fall off.

The plant needs to be watered regularly, especially during hot weather.

If the leaves start to droop, that’s a sign that the plant is thirsty. Water the plant thoroughly, making sure to soak the roots.

3. Extreme Temperatures

Rhododendron plants prefer cool weather and cannot tolerate extreme heat or cold.

If the temperature gets too high or too low, the leaves will start to fall off.

To protect your plant from extreme temperatures, keep it in a cool room during hot weather, and bring it inside if there is a chance of frost.

4. Lack of Light

Rhododendron plants need bright, indirect light to thrive.

If the plant is not getting enough light, the leaves will start to turn yellow and fall off.

Rhododendron plants need at least four hours of indirect light per day.

If your plant is not getting enough light, try moving it to a brighter location.

An east- or west-facing window is ideal if the plant is not in direct sunlight.

5. Too Much Sunlight

While rhododendron plants need bright light, too much sunlight can cause the leaves to fall off.

If the plant is in direct sunlight, the leaves will start to turn brown and fall off.

To protect your plant from too much sunlight, place it in an east- or west-facing window, where it will get bright light but won’t be in direct sunlight.

You can also try shading the plant with a sheer curtain or blind.

6. Soil Problems

Rhododendron plants need well-drained, acidic soil to thrive.

If the soil is too alkaline, the leaves will start to turn yellow and fall off.

To fix this problem, you can try adding some peat moss or compost to the soil to make it more acidic.

You can also try growing rhododendron in a pot with an acidic potting mix.

7. Nutrient Deficiencies

Rhododendron plants need a balance of nutrients to stay healthy.

If the plant is not getting enough nitrogen, phosphorus, or potassium, the leaves will start to turn yellow and fall off.

The best way to fix a nutrient deficiency is to fertilize the plant with a balanced fertilizer.

You can also try adding some compost or organic matter to the soil to help improve the nutrient content.

8. Pest Infestation

Pests can also cause rhododendron leaves to fall off.

Common pests that attack rhododendron plants include aphids, mites, and scale.

These pests suck the sap from the leaves, causing them to turn yellow and fall off.

You can try spraying the plant with water and dish soap to get rid of pests.

You can also try using a natural insecticide, such as neem oil.

9. Diseases

Diseases can also cause rhododendron leaves to fall off.

Common diseases that affect rhododendron plants include root rot, leaf spot, and powdery mildew.

Fungi or bacteria can cause these diseases and spread quickly if the plant is not adequately cared for.

Root rot is the most dangerous disease, as it can kill the plant.

To prevent diseases, make sure to water the plant at the base and not on the leaves.

You should also remove dead leaves or branches from the plant, as they can harbor diseases.

If your plant does get a disease, you can try treating it with a fungicide or bactericide.

10. Poor Air circulation

Rhododendron plants need good air circulation to stay healthy.

If the plant is not getting enough air, the leaves might start to fall off.

Poor air circulation can be caused by overcrowding, placement in a corner, or placement behind a piece of furniture.

This can result in a build-up of heat and humidity, which promote the growth of fungi and bacteria.

You can try moving the plant to a more open area to fix this problem.

You can also try trimming the branches to improve air circulation.

11. Chemical Burns

Chemicals can also cause rhododendron leaves to fall off.

If the plant is sprayed with a chemical, such as an insecticide or herbicide, the leaves might start to turn brown and fall off.

To protect your plant from chemical burns, read the label carefully before using any products.

You should also avoid using chemicals near rhododendron plants.

12. Transplant Shock

Transplant shock can also cause rhododendron leaves to fall off.

This usually happens when the plant is moved to a new location.

The stress of the move can cause the leaves to turn yellow and fall off.

To prevent transplant shock, slowly acclimate the plant to its new environment.

You can do this by placing the plant in a shady spot for a week and then gradually moving it to a sunnier location.

In most cases, the plant only needs adjusting time, and the leaves will eventually grow back.

13. Natural Shedding

In some cases, rhododendron leaves falling off is a natural process.

This usually happens in the fall, when the plant prepares for winter.

The leaves will turn yellow and fall off as the plant goes into dormancy.

There is no need to worry about this, as it is a normal part of the plant’s life cycle.

What To Do When Rhododendron Leaves Fall Off?

It is essential to identify the cause of rhododendron leaves falling off.

Once you know why the leaves are falling off, you can take steps to fix the problem.

Here are some things you can do:

1. Check The Soil

The first thing you should do is check the soil.

Rhododendron needs acidic soil to thrive, so ensure the pH is between 4.5 and 6.

The leaves will turn yellow and fall off if the soil is too alkaline.

They also need well-drained soil to ensure the plant is not sitting in water.

2. Check The Leaves

The next thing you should do is check the leaves.

Look for signs of pests, such as holes or discoloration.

You can also try looking for webbing or eggs on the underside of the leaves.

You can try spraying the plant with a pesticide if you see any pests.

3. Check The Temperature

Temperature can also cause rhododendron leaves to fall off.

The plant prefers cool temperatures, between 50 and 70 degrees Fahrenheit.

If the temperature gets too hot or too cold, the leaves might start to fall off.

You can try moving the plant to a cooler or warmer location to fix this problem.

You can also try using a fan to circulate the air around the plant.

4. Check The Light

Rhododendron plants need bright, indirect light.

If the plant is not getting enough light, the leaves might start to fall off.

But also, if the plant is getting too much direct sunlight, the leaves might start to turn yellow and fall off.

You can try moving the plant to a brighter or darker location to fix this problem.

East-facing windows are usually the best option for rhododendron plants.

5. Check The Watering Schedule

Watering is another essential factor to consider.

Rhododendron plants like to be kept moist but not wet.

If the plant is too dry, the leaves might start to fall off.

But if the plant is too wet, the roots might start to rot.

To fix this problem, you can try adjusting your watering schedule.

Water the plant when the soil is dry to the touch.

6. Check For Pests

Pests are another common reason for rhododendron leaves falling off.

Aphids, spider mites, and scale insects are all common pests that can attack rhododendron plants.

You can try spraying the plant with a pesticide to get rid of pests.

You can also try using a soap and water solution.

Mix 1 teaspoon of dish soap with 1 quart of water, and spray it on the plant.

7. Check For Diseases

Diseases are another common reason for rhododendron leaves falling off.

Powdery mildew, root rot, and leaf spot are all common fungal diseases affecting rhododendron plants.

To treat diseases, you can try using a fungicide.

There are some natural options, such as neem oil or baking soda.

Or you can use a chemical fungicide.

8. Check The Fertilizer

Fertilizer is another essential factor to consider.

Rhododendron plants need to be fertilized every two weeks during the growing season.

But if you fertilize too much, the leaves might start to fall off.

To fix this problem, you can try using a lower-nitrogen fertilizer.

You can also try fertilizing less often.

9. Check For Poor Air circulation

Poor air circulation is another common reason for rhododendron leaves falling off.

If the plant is not getting enough air, the leaves might start to turn yellow and fall off.

You can try moving the plant to a location with better air circulation to fix this problem.

You can also try using a fan to circulate the air around the plant.

10. Check The Plant For Damage

Last but not least, you should check the plant for damage.

Physical damage, such as wind or heavy rains, can cause rhododendron leaves to fall off.

To fix this problem, you can try trimming off the damaged leaves.

You can also try protecting the plant from future damage by covering it with a tarp or plastic sheet.

How to Prevent Rhododendron Leaves from Falling Off

Now that you know the common reasons for rhododendron leaves falling off, you can take steps to prevent it from happening.

Here are a few tips:

  • Make sure your rhododendron is getting enough water. These plants like to stay moist, so water them regularly, especially during hot weather.
  • Fertilize your rhododendron with an acidic fertilizer. You can find these at most garden stores.
  • Mulch around the base of the plant to help retain moisture.
  • Prune away any dead or dying leaves or branches. This will help the plant focus its energy on healthy growth.
  • If your rhododendron is in a pot, make sure the pot has drainage holes to allow excess water to escape.
  • Insects can sometimes be the cause of rhododendron leaves falling off. If you see any insects on the plant, remove them and treat the plant with an insecticide if necessary.
  • Keep an eye on the temperature. Rhododendrons can be sensitive to changes in temperature, so make sure they’re not in a spot that gets too hot or too cold.

Following these tips can help prevent rhododendron leaves from falling off. If you do notice the leaves falling off, take a look at the

What Are The Benefits Of Rhododendron Leaves Falling Off?

Rhododendron leaves falling off can be a good thing for the plant.

It’s a way for the rhododendron to get rid of old, damaged, or diseased leaves to focus its energy on new growth.

So, if you see some leaves falling off, don’t be too alarmed.

Just look at the plant and see if there are any other signs of distress. If not, then the rhododendron is probably just doing its natural thing.

What To Do With Rhododendron Leaves That Fall Off?

You can collect the rhododendron fallen leaves and use them for other purposes.

For example, add them to your compost pile or use them as mulch around other plants.

For example, you can compost them or use them as mulch around other plants.

Or, if you’re feeling creative, you can even use them to make rhododendron leaf crafts!

So, don’t throw away those rhododendron leaves that fall off. There are many uses for them.

Final Thoughts

Rhododendron leaves falling off is a normal process for the plant.

It’s a way for the rhododendron to get rid of old, damaged, or diseased leaves to focus its energy on new growth.

Don’t be alarmed if you see some rhododendron leaves falling off. Just look at the plant and see if there are any other signs of distress.

If not, then the rhododendron is probably just doing its natural thing.

However, it’s time to take action if you see rhododendron leaves falling off in large quantities or if the plant looks otherwise unhealthy.

You need to determine the cause of the problem and take steps to fix it.

In most cases, you can get your rhododendron back to good health with proper care.