When you say lettuce most people think Iceburg head lettuce. In reality lettuce has a lot of varieties but all of the varieties of lettuce can be narrowed into two groups; head lettuce (such as Great Lakes 118 and Romaine) and leaf lettuce (such as Black Seeded Simpson and Prizehead). Lettuce seeds can be direct seeded as early as soil can be worked or started indoors in early spring. Lettuce Heirloom Seeds grow into annual plants. Lettuce is easy to grow, but will bolt quickly in the high heat of summer.