Joanne,
You prompted me top look at my planning calendar. If my last frust date really is April 6, I should laready be starting Salvia & Petunia & Viola indoors.
The "start N weeks before last frost" info in it was scrounged from seed pkts, websites and old gardening books. Not really tested yet, because I usally start things late through procrastination, busyness due to business, and sloth.