karen brown, gardener
I just pruned some grape vines (12 years old) that have a dark brown center to the stems and the bark is shredded. Is this a fungus and how do I treat it?
Lake County Oregon
The vines are fine for now. The bark of the grapevine naturally shreds away. They call this exfoliating bark. It is just the non-functional part of the vine. It is normal. The central area may have discoloration. If it was badly winter injured then it may be a problem. If it buds out normally this spring then all is OK, if not then you may have a canker problem but I think that unlikely at this point.
BTW - you may see the cut portions of the vine "bleed" or drip sap as the weather gets nice. No worry there either.