It's so late in the season, I wouldn't bother treating them unless you start to have rotting stems and those I'd treat by cutting them back to healthy looking pieces with sterilized cutters. Treating when fungal issues are already wide spread doesn't do much good, the treatments are preventative rather than restorative. This fall cut all herbaceous foliage and stems down to an inch of the ground, I'd wash whatever you use to cut them with a bleach/water soaked cloth between cuts and ABSOLUTELY between plants, try not to let infected foliage touch the ground and dispose of it in the trash, don't compost or keep on site.
