A Bad Case of Five-Finger Blight

I have four Boysenberry/blackberry vines. Two are new this year and I knew I wouldn't get any fruit from them. But the two I planted last year showed great promise this Spring, with plenty of blossoms. I was sooo excited to get fresh, homegrown berries. I guess I gloated a bit too much to the kids about how good they were, though, as they started picking the berries before they were even fully ripe. Must be the current mania for sour candies that made them palatable.

This here vine should have been covered with fruit, but the only fruit I found was waaay up at the top of the vine, out of reach of the kids. Guess if I want to get any fruit for myself or for jam I will need to train next year's vines up on the top of the wall.