There is 4 basic types of lettuce;Looseleaf lettuce is the most heat tolerant and easiest to grow. The leaves are loosely bunched instead of a tight head and harvest can be extended by cutting a few leaves at a time. There are many types and colours such as Grand Rapids, Simpson & Salad Bowls.Head Lettuce includes both Butterhead, Boston & Iceburg types. All are wonderful in salads. Butterhead has leaves that form small open heads, and get their name from the buttery center of the head. Iceburg, or Crisphead is your traditional head lettuce. Romaine (or Cos) lettuce forms upright clusters of leaves. The crisp texture is a salad staple in Caesar Salads. Simply Salad™ delivers the first-ever multi-species, multi-pellet salad mixes. Each pellet contains a tasty, good looking, well balanced mix of greens that can be grown in 4 –6 in/10-15 cm pots or color bowls. Gardeners can harvest every 3 weeks by cutting back to 2 in/5 cm and re-grow several times.