How often do you spray Hybrid Teas?
I missed a spraying and sure enough, some of my HTs are showing signs of blackspot--going 4 weeks without spraying is too long, even for Bayer Advanced disease control.
In the past, I've found that spraying Immunox every week works well, as does Bayer Advanced every other week. We have a humid climate--50 or 60% is hardly unusual, it is 80 degrees and 60% humidity right now. Rain in the past month has been 5 inches--on six occasions we got at least half an inch of rain.
Wonder what works for others if you want fully foliated Hybrid Teas throughout the growing season?