Posted: 10/10/2013 at 21:07
It does depend on the seed you're sowing and the time of year. Some seeds need a peroid of cold and then others germinate in warmer weather.
I think of hardy as plants that can withstand the winter, half hardy might die if it gets cold enough. A frost will kill tender annuals such as nasturtiams, morning glory, lobelia, cosmos etc, some of these are still flowering now.
What other seeds have you got going?