Those black necrotic lesions


I don’t have them on anything right now. I have had them in the past on two different cultivars, several years apart in gardens separated by several hundred feet.

The first were on both plants of Royal Bonica from Park Wayside that I had been growing for about four years. The two plants were three feet apart. Suddenly there were black lesions on about half the canes of each, not girding the canes but apparently moving down the stems on about half of the canes circumference. I had had some die back in spring issues with some new plants so I was obsessive about cleanliness and I cut the canes about an inch below the lowest black, then sanitized the pruners with lysol bacteria and virus spray, air dried them, and then recut an additional inch lower. One bush survived, one didn’t.

The second appearance was two years later on a bush of the poly Verdun that had been in place for four or five years. It came from Sequoia. On it, the black appeared within sprays and appeared to have moved downward. On this one, too, there didn’t appear to be a spread to gird the cane.

On this, I cut even deeper, ,about two inches down, twice, and that bush hasn’t had a recurrence.

The black on these was a deep black, one that grabbed attention because there was no transition…just black.

(And we sent the canes to the landfill double bagged in plastic, but that’s because of our other disease problems with RRD…cautions are us. )