Well, I had wondered what "taking great exception" meant, and unfortunately I found out. BS has been very bad this year and Hyde Hall was beginning to spot worse than last year, so I ignored the caution and sprayed (I use Honor Guard and apply strictly according to directions). Within two weeks 90% of the leaves dropped off. Just gone. I'm pretty convinced that it's the result of spraying because there are two shrubs at the end of the hedge that had been clean and I recall leaving them alone and they look ok. Not too badly spotted either.

Has anyone else had this reaction and if so on which of their roses? Are certain varieties more prone to this reaction? Would spraying with insecticide have this same effect or do you think the issue is strictly related to fungicide?

I've grown one rugosa rose and have never sprayed it--because it has never succumbed to blackspot.

I think it is the fungicide, not the insecticide, which causes the problem on some roses, but I can't say for sure. Will be interesting to see what others have to say also.

Kate


Meant to add that I'm so sorry to hear about your Hyde Halls. I'm sure they will recover--but that isn't much of a consolation as one is sitting there contemplating them in their disaster mode, is it!

It isn't just fungicides that can hurt rugosas. Some miticides are potentially phytotoxic, as are all oils, soaps, and detergents, and Wilt Pruf. I have heard reports of Sevin insecticide burning plants.

This is the first time I have heard of propiconazole burning roses.

Rosefolly

The hedge is long, situated N-S with the north end getting a bit of shade and hence more BS pressure. I had sprayed only the end that was showing BS. The last two plants on the south end had held onto some of their foliage but as the BS progressed, they also dropped their foliage.

I considered that I don't want a hedge of bare sticks and if fungicide and/or BS was going to cause defoliation, I may as well scrap HH (ouch$!) and plant something else. I figured I had nothing to lose so I began regular spraying and hoped for the best, first a dose of Moncozeb, then routine Honor Guard.

I fertilized with Neptune's Harvest kelp meal and a few doses of Miracle Grow and by the end of the summer I had decent new foliage. I can comfortably report that the fungicide isn't harming the foliage.

BTW the bushes remained constant bloom throughout the whole ordeal.