Last Night's Frost warning

Last night, there was a frost warning in some part of New England including the area where I live. The weather was so good for the past couple of weeks so I planted some tomatoes and even eggplant in our small garden. I also had some flowering annuals that I planted. So last night when the frost warning was announced I covered some of my plants to protect from frost. I learned my lesson, next year I won't plant sensitive plants until after Memorial Day.