Sorry if this has been asked in the past - I know it can get irritating answering the same questions, but I have done searches on here, google and yahoo - honest :) - but can't really find an answer.
I've got two raspberry bushes as presents for the allotment- one is Glen Cova and one is Malling Jewel. GC is fine - all strong green growth at ground level - but MJ is turning purple on several leaves. I looked up diseases and began to worry that this might be cane blight but none of the pictures that I could find quite match. I've separated the two plants in case its contagious but don't want to do anything radical to the MJ in case it turns out this is not a problem.
Any advice would be greatly appreciated.