Last year around end of summer our two blueberries growing on our balkony got some illnes. On the branches grew a lot of bulges (a few mm width and height, but around 1cm long), first sporadic and later in dense packs. It was possible to remove them with a simple touch, they did not grew inside the branch, just outside. A gentle pinch on the bulge revealed a lot of white fluffy stuff. At the same time the leaves and everything else got covered by some black smut. The leaves itself did not turn black since it was possible to remove it with a sponge and some water. Not only on the plant, the pot and tiles below got covered in it as well.
I removed the worst leaves and the plants got its usual cut before the winter, they are both having new buds but still the black stuff is around on the branches. We have cold winters (was around -15C for a week or two). All bulges got removed. Sadly I do not have any pictures of it.
Does someone have an idea what it is and how to treat it?
Edit Living in Europe - Slovakia.