Yellow leaves on Photinia

I have one of the smaller varieties of Photinia, I thought it was Little Red Robin but now have a feeling it's Carre Rouge.
It was beautiful a few weeks ago, lovely new red growth, but a lot of the leaves are now turning yellow.
I'd put money on it being due to drought, we have had no rain for weeks and clearing out plants from the bed around it the soil can best be described as dust.

Obviously I am making sure it's now getting plenty of water but I'm wondering whether or not I should feed it at the same time ?
Any advice gratefully received .

 

When I had a brief spell in a hedging nursery years ago, both laurels and photinia grown on from 7" pots had a annual top dressing of 20-20-20 fertiliser once planted out and seemed to thrive upon it

 

Thanks @infradig

 

I would not feed until there are signs of recovery. Keep up with the watering even when the leaves perk up.

 

Will do @Goldenlily26 .

 

Check for honey fungus - if it is, the sooner you know the better.

 

Will do @Howard Stone .