When to Start Plants from Seeds

Starting plants from seed is one of the most rewarding gardening practices - if only for the chance to get your hands in the soil in the dead of winter. When to start seeds is a matter of experience, guessing and math. Many gardeners still plant by the moon. Others rely on phenology, the study of how plants and animals respond to seasonal changes in their environment. For example, you know it's time to plant your peas when the forsythia blooms.

http://gardening.about.com/od/gardenprimer/a/SeedStarting.htm