What's wrong with my Rhododendrons?

I'm seeking the help of the forum in regards to my newly planted rhododendrons.

I bought six rhododendrons in July from a good nursery nearby and planted them up however they now have discoloured bottom leaves which they are dropping. They still seem healthy higher up the plants.

The 2 Rododendron 'sappho' looked like that at the nursery so I supposed that they just drop their lower leaves anyway as this is a tall, leggy variety but I'm pretty sure the others ( Rododendron 'Lord Roberts', R.ponticum (variagated non-invasive)shouldn't be doing it.

My soil is acidic (tested at pH~5.6), I haven't planted them too deep and they have been getting plenty of water. They are in part-shade.

There seem to be a lot of discussions about fungal infections and things but few have photos to compare and I am a total novice.

I'd be grateful if you could have a look at the photos and help diagnose my poor rhododendrons - I don't want to lose them.

 

Dont panic, its too soon for that!
See this:
When do evergreen trees lose their old leaves? - Barcham

 

I assume you have acid soil, and have been watering them during the hot spell.
Is your tap water hard if you have been using a hose?

Its just that they look chlorotic to me.

 

Thanks, I really do hope it's just part of their natural cycle/a wee bit of shock from being transplanted.

As I said though, I'm a total novice and am inclined to assume I've killed everything I've planted.

 

Thanks for replying, yes the soil is acidic with lots of rotted organic matter. I planted them with a healthy amount of ericacious compost as well.
They've been getting a good watering and our water is very soft (Renfrewshire, Scotland).

As to them being chlorotic, I agree. I was going to give them a dose of Vitax seaweed sequestered iron to see if that helps - is that a good/bad idea?

 

I dont think it would hurt, but might take a few weeks to work if it is the problem.

Maybe the plants are struggling to get out of the existing root ball if its been dry in your area.
Often the rootball of plants planted out late in the year dry out and without water added directly to the neck of the plant as a trickle, dry right out and are difficult to re wet.