You know what I'm stunned by? The difference between
these maps showing the average "last frost date",
and the
USDA zone/hardiness map showing the minimum temperature
My average date of last spring frost is, for example, comparable to South Dakota, despite the fact that I'm two hardiness zones warmer. Or, phrased differently, the one zone difference between me and my mom in Alabama translates into a month difference in frost date, but only 2 weeks difference in length of growing season. Huh.
The moral of this story: I should stop looking at maps and get the indoor seeds started, or I'll be buying everything for $3/plant at the greenhouse.