The shrubs probably need a good feed using Ericacious plant food or sequesterine, also give them a nice mulch, which will give them some TLC ! We have had some winds & frost too which does not help ! I have fed mine but we have had no rain for weeks so have to keep watering them with rain water only because these plants like an acid soil. Good luck

What rainwater? Iv'e run out of rain water and I have 3 butts! Not rained for a long time now in London area.

Yes I forgot to say I have no more rain water either, we need some desperately.