I think all plants need feeding, so I give mine a handful of ericaceous plant feed which I lightly hoe into the soil. I'm sure there are lots of different types of feed that would do, but it's safest to stick to the ones specifically for the kind of plants who need acidic soils.

I only feed mine once a year after it flowers but I do mulch it spring and autumn.

Thanks Louisa15 and Drc726 I will do what you have suggested