I have a Corkscrew Hazel (Corylus avellana 'Contorta') that has developed these rows of raised brown spots (for want of a better word) along quite a few branches. The spring growth on those branches was weak and there has been no further growth this year on the branches infected with these spots. The rest of the shrub has grown normally. These spots are in rows with sunken brown tissue connecting the spots along the branch making me think it may be some sort of fungal infection but I don't know. I know they are not scale insects as they cannot be scraped off or squashed like scale. Does anybody have any idea of what this is and if it is treatable at all? Is it best to dig out the shrub or can it be cut back and treated with a fungicide or something else?
