Yellow-brown leaves on rhododendron

A few days ago my wife and I re-potted a rhododendron from the plastic pot it came in into a larger outdoor pot using Gro-sure ericaceous compost with some Miracle gro all purpose continuous release plant food mixed in. We finished it with some white decorative stones around the base of the plant to try and prevent weeds. The pot was then put out on the patio where it receives dappled sunlight for most of the day.

A few days after we did this the leaves at the top of the plant went from being solid green to having a yellow-brown tinge. We are worried we've done something wrong but we don't know what. We googled and came up with loads of possible problems, have we put the root-bulb too deep, perhaps it doesn't like having the stones around the base, it's getting burned by the sun, it's got a disease or any number of other possible causes.

Do I need to worry about the changes to the leaves?
What should I do about it?

Thank you!

 

It does look like the top leaves have scorched.
Possibly sunlight that it has not been used to.

I'd be a bit wary of those chippings they look like they could possibly be limey and rhododendron don't like lime.

 

Pete,

Thank you for the advice. You are right that it isn't used to sunlight as we had been keeping it indoors before.

I'll also remove the stones for safety.

 

OK, so best to acclimatise it gradually, its also not used to outdoor conditions either, so best to take it slowly.