You could have a bit of tidying up around the plants with perhaps a mulch and a drop of magnesium (Epsom Salts). You would need to wait until the spring before giving a bit of a trim and feed in the shape of blood, fish and bone or Growmore or if the wallet will allow then Vitax Q4 is excellent.

Are they possibly being knocked by the mower when you cut the grass? The whole area looks a little sad and uncared for, as Jimmy says get rid of the dead vegetation around the shrubs and give them dome t.l.c.

Check the backs of the leaves looking for pink spores - best to eliminate box blight first