Rosette Reckoning

'The Magician' Rose Rosette

I suppose some are wondering why ProfessorRoush has been so quiet for the past 9 days?  I'd like to tell you that I've been on a fabulous vacation to a tropical isle, but truthfully I've just been swamped with lots to do and haven't the extra energy to write.  Well, that, and my gardening depression over what I'm about to show you.

Last Saturday, after the leaves finally were blasted off the roses by a cold spell, I used the opportunity of the bare stems to assay my roses for any signs of Rose Rosette disease.  And, of course, I found plenty of possible lesions, on 5 different roses to be specific.  One of the more definitive examples is pictured at the upper right, from a cane on 'The Magician', a recent shrub rose bred by Dr. John Clements.  The red arrow shows the thickened, thorny cane in question, originating from the much smaller branch indicated by the white arrow.

'Darlow's Enigma' Rose Rosette

Other lesions, such as that on 'Darlow's Enigma', pictured at the right, and 'Vanguard', pictured below left were a little less certain, but still highly suggestive.  The fourth and fifth possible victims are unfortunately two Griffith Buck roses, 'Iobelle' and 'September Song'. 

In the positive column, only a single cane was affected on each rose and each one high on the cane at that, and I wacked every one of these diseased canes off at the ground level in hopes that the virus didn't spread to the base.  I would also note that none of these roses are over 3 years old (are they thus more susceptible than established roses?) and that I found no lesions on any of  my Old Garden Roses or my "real" Rugosa Hybrids (I don't really count 'Vanguard' here since its foliage is not very rugose).



'Vanguard' Rose Rosette

On the negative side, two of these newly affected roses were Griffith Buck roses, increasing the affected number of those hybrids to 3/6 in my garden.  Thus 50% of the roses affected so far are Buck roses, although Buck roses do not account for nearly 50% of the roses in my garden.  Are they more susceptible?  Or am I seeing more on Buck hybrids because they constitute a majority of my "modern" rose hybrids; those that are not either Hybrid Rugosa or Old Garden Roses?  I don't know.