Why is my rhododendron dying?

Why is my rhododendron dying?

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It’s quite difficult to kill rhododendrons, so are you sure that your rhododendron is dying? Many problems with rhododendrons can be fixed, so don’t give up on your plant yet. Here are some of the common problems with rhododendrons and what to do about them.

Growing environment

Planted in the wrong environment in the wrong soil PH rating

Rhododendrons like moist but well-drained soil and to be in partial or dappled shade. They do need sunlight but not hours of direct sunshine as they naturally grow in the shade. They also prefer acidic soil of pH5 to pH6, which you can test with a soil ph testing kit. They’re susceptible to problems if they’re in an exposed location, especially to cold winds.

What to do

Check all these factors of your plant’s growing environment. Change any that are not in the rhododendrons’ best interests. The most difficult to change is the acidity of the soil. If you have alkaline soil, consider transplanting the plant (in October) to a more suitable location or growing it in a pot if its not too big.

Planted too deeply

Plant Rhododendrons in acidic soil

Rhododendrons need to be planted shallowly as they are a surface rooting plant. The top of the root ball should be just below or at the level of the ground. As the roots are so close to the surface, covering them with a layer of acidic mulch helps to keep them cool and lets them retain moisture better.

What to do

If your rhododendron’s roots are deeply planted, excavate around them to bring them to remove some of the covering soil. Apply the layer of acidic mulch for their protection. Keep the mulch loose and aerated and don’t pack it down tightly.

Using the wrong water

Yes, you can use the wrong water on your rhododendrons. And this is tap water if you live in a hard water area. Hard tap water contains a significant amount of calcium which reduces the acidity in the soil. This affects the roots of the plants, which in turn affects the foliage and flowers.

What to do

Using collected rain water to water rhododendrons and not hard water from my tap as this can harm the plant

As much as possible, use rainwater to water your rhododendrons (and even all your flowers). This involves using a rain barrel to collect rainwater. If you run out of rainwater in the summer, it’s OK to go back to using hard tap water for a few months.

Pests and diseases

Leaf scotch and mildew effecting Rhododendron

Your plants’ growing environment may contain pests and/or diseases. These are easier to track down by looking at the symptoms of the problem rather than trying to find miniscule insects and spores. Read Rhododendron pests and diseases for all the details.


If you’ve checked your rhododendron’s growing environment and it all looks fine, hone in on the specific symptoms that make you think that your rhododendron is dying.

Buds falling off

I cover this issue in Why are my Rhododendron buds falling off?

Leaves falling off

There are many reasons for this. Check out Why is my rhododendron dropping its leaves? for information.

Plant turning yellow

Whether it’s the leaves, flowers or stems that are becoming discoloured, you need to read Why is my rhododendron going yellow?

Leaves turning brown

If your leaves are brown instead of green, the problem could be leaf scorch or powdery mildew. Read Why has my rhododendron got brown leaves? to find out what to do about this.

White powdery substance

This is probably powdery mildew. I’ve given it its own article as it’s such a common problem for many plants. Please read Rhododendrons & Powdery Mildew.


If you are still convinced that your rhododendron is dying, consider taking some cuttings to propagate the plant. I have information on how to do that in How to propagate rhododendrons.

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