Rhododendron - what's up with it?

[Marcher]

I added fresh compost and some bark and then noticed it seemed to be suffering from something so removed the bark. I thought bark would make the soil acidic which would be good for the plant but guess they might have been treated with something.
I removed it and it still is declining despite all the rain washing out any potential contaminants. So what could be wrong with it?









It's a Rhododendron 'Alfred' btw.

[Two_Sheds]

what brand of compost did you use?

[Marcher]

what brand of compost did you use?

Aldi stuff with peat included.

[Two_Sheds]

How long have you had the plant? Has it always been in that container? When you say fresh compost, is it all fresh, or did you top dress its old pot?

When you say declining, do you mean those brown edges on the leaves?

What's your watering regime? (the compost looks soggy to me, but that might just be its normal colour)

[Marcher]

How long have you had the plant?

Since spring and it did great until recently.

Has it always been in that container?

Yes.

When you say fresh compost, is it all fresh, or did you top dress its old pot?

Yes, it was top dressed and covered with bark. I latter removed the bark because the Rhododendron started turning brown but it didn't seem to stop it.

When you say declining, do you mean those brown edges on the leaves?

Yes. Some of the leaves were very brown and fell off, others I removed to tidy it up a bit.

What's your watering regime? (the compost looks soggy to me, but that might just be its normal colour)

I only water it on very hot days in the evening. Usually rain does the job for me and it's rained here heavily for a few days. The Rhododendron has been suffering for a few weeks though.
The compost is a dark black colour anyway.

[Glutton4...]

Are you using Ericaceous compost? If not, it will gradually get more and more sickly over the weeks and months. They also don't really like full sun when it is very hot.

To me, it looks over-watered, but I'm by no means an expert on them. I just happen to have a customer who insists in planting them in her garden, despite it being completely the wrong type of soil. She has been told, but just loves them so much that she is prepared to lose them after a year or so.

[Marcher]

Are you using Ericaceous compost?

Not really, I just figured that it had peat in it so it'd be slightly acidic anyway.

If not, it will gradually get more and more sickly over the weeks and months.

I'm not sure, I bought it around may and it's been fine until a few weeks ago.

To me, it looks over-watered,

It's been raining heavily over the past for days. I don't usually water it because there's usually enough rain to do that for me.

I just happen to have a customer who insists in planting them in her garden, despite it being completely the wrong type of soil.

Won't she have more success if she digs a much deep and wider hole than required and replaces the soil with ericaceous compost?

[veggiechicken]

Is the drainage in the pot adequate - or could it be stagnating at the base?

[Marcher]

No, the drainage is fine (I've checked). I'm wondering if when I top dressed it and added bark if that did anything. I think I remember hearing something about not covering the top of Rhododendron root balls and the compost and bark may have done that until I noticed it suffering.

[veggiechicken]

If you're worried about it, why not repot it into ericaceous compost? Set your mind at rest!

[Two_Sheds]

"soil-less potting media...can lose their structure over time leading to poor drainage and an airless root environment, causing leaves to brown and die back"

Rhododendron / Royal Horticultural Society

does that sound likely in your rhodie's case?

[Marcher]

"soil-less potting media...can lose their structure over time leading to poor drainage and an airless root environment, causing leaves to brown and die back"

Rhododendron / Royal Horticultural Society

does that sound likely in your rhodie's case?

No, the compost is fine. I took it out a few days ago to examine the plant and re-planted it. The drainage is very good - a bit damp towards the bottom but drier towards the top (it wasn't sitting in water).
It wasn't compacted or anything either.

[Nicos]

I'm wondering if it's early stages of Sudden Oak Death?
It's illegal to bring rhododendronas and azalias into France from the UK for that very reason.
Have a goooogle at a few piccies. Some of them look similar.

[Marcher]

I doubt it being sudden oak death. Oaks around here have mildew have problems with mildew, not really sudden oak death.
It's not getting any worse anyway, I think it must have been something in the bark. It might have been treated with something or might have suddenly changed the soil PH and caused the Rhododendron to suffer.

No other leaves seem to be going brown and it's putting out fresh leaves to compensate. I think it was the bark.

[Dusty Rhodes]

It looks a bit too wet...

Use a cheapy ph meter and measure the ph...no point in guessing. If you don't have one, it's money well spent.