First day I've seen any frost on the plants so I had to snap some pictures. The burgundy glow is always a favorite of mine with frost. The first frost here average date is up for debate. I have seen tables saying anywhere from 12th to 19th for Peoria. The tables that haven't updated to the new hardiness zoning typically say 12 or 14th for Peoria, whereas the sites that changed our hardiness zone from 6a to 5b also changed our average first frost date to 19th. Now one year does not a study make, so this year's 25th date certainly doesn't prove anything by itself but as I have been gardening is it 4 or 5 years now the trend has been 19th or later.
So many of the perennials are beautiful when they are dusted with frost.