Something attacked black raspberry plants over the winter

Asked April 27, 2017, 11:52 AM EDT

I have a small patch (8 x 12?) of black raspberries that self-seeded 10 years ago or more. For the past five years I have using them to make unbelievably good jam. The plants are not nicely arranged,but I have resisted doing anything about that because they have been so productive. Last year they were especially fruitful. I trimmed the floricanes in the fall, didn't particularly inspect the primocanes but I think I would have noticed extensive damage. A few weeks ago I went out and saw a number of broken canes, thought it was animal damage. Now I went out to weed and discovered this disease on all but a couple of plants. I will trim off the plants that are fully infected (to the top of the knot of canes? to the ground? to below the ground?) but I wonder about both the couple of plants that seem uninfected and any that have both affected and unaffected canes. Can I leave any "good" canes alone, or should I just cut them all down? (Am I right that new growth will eventually produce fruit?) Thank you.

Hennepin County Minnesota

4 Responses

It appears to be rabbit damage and, yes you can leave any undamaged canes. Prune others to soil level, you might think about fencing you bed.

Thank you very ,much. Rabbits have been at my spring flowers; didn't suspect them in this.

How high should rabbit fencing go? Don't want to make the berries difficult to pick.