Hi. I have a bramble that came with the house. The first year it made big purplish raspberries. I wondered if it was a tayberry or loganberry. No way to know. But this is the third summer of small, crumbling berries. It is in a patch with lots of more standard type red raspberries which are all fine. Water has not been an issue (especially this year). I suspect a virus. There are lots of wild thimbleberry and black caps nearby. My guess is the red raspberries are not susceptible. Does this theory make sense? Is there any way to save this bramble?