BTW, I’ve started spraying my roses with this stuff every 2-3 weeks. No black spots! And it’s WAY cheaper than the bought stuff for black spot. I dilute it a bit more, 6oz to a gallon.
Just saw your comment on use of the bleach solution for roses with the spotting. Some of our roses have that. Where do you get the bleach for this solution? All the stuff in the grocery stores around here have additives.